Use of inhibitor and therapy

Abstract

The present invention relates to a combination therapy for treating metastasis of a GD2-positive cancer, such as relapsed or refractory neuroblastoma. In particular, the combination therapy comprises administration of stereotactic body radiotherapy (SBRT) at one or more metastatic sites in combination with administration of an anti-GD2 antibody or fragment thereof.

Description

[0001] USE OF INHIBITOR AND THERAPY

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority under 35 U.S.C. 119(e) to the U.S. Provisional Application No. 63 / 673,805, filed on July 22, 2024, which is hereby incorporated by reference herein in its entirety.

[0004] REFERENCE TO A SEQUENCE LISTING

[0005] This application contains a Sequence Listing XML, which has been submitted electronically and is hereby incorporated by reference in its entirety. Said Sequence Listing XML, created on July 18, 2025, is named EPCLP0121WO Sequence Listing. xml and is 20,208bytes in size.

[0006] FIELD

[0007] The present invention relates to a combination therapy for treating metastasis of a GD2-positive cancer, such as relapsed or refractory neuroblastoma. In particular, the combination therapy comprises administration of stereotactic body radiotherapy (SBRT) at one or more metastatic sites in combination with administration of an anti- GD2 antibody or fragment thereof.

[0008] BACKGROUND

[0009] Neuroblastoma typically develops in the sympathetic nervous system, originating from neuro crest cells. The genetic basis for neuroblastoma is complex, with the disease arising from both hereditary and non-familial pathways. Sequencing data from large patient cohorts has shown that multiple genes play a role in disease causation with mutation in MYCN, ALK, ATRX, CD79B, and SOX9 frequently observed.70Recent genome-wide association studies (GWAS) have identified common single nucleotide polymorphisms (SNPs) that increase the likelihood of disease susceptibility including SNPs in genes such as BARD1 and LM01.

[0010] Neuroblastoma is one of the most prominent solid tumour cancers occurring in children under 5 years of age with nearly all patients diagnosed by age 10. Neuroblastoma accounts for up to 8% of malignant cancers and contributes to approximately 15% of childhood cancer mortality. Approximately half of all patients diagnosed have high risk disease with an approximate survival rate of around 50%. Around 15% of neuroblastoma cases can be classified as either refractory or relapsed in which the disease either proves recalcitrant to therapy or subsequently recurs. For these cases, disease outcomes are substantially poorer. Therefore, the identification of effective regimes remains a high priority.

[0011] Current treatment options are divided into three phases: induction, consolidation, and post-consolidation / maintenance therapy. Potential treatment options include chemotherapy, surgical resection, combination therapy of chemotherapy and autologous stem cell rescue, radiation therapy, immunotherapy, and isotretinoin.71Long term side effects from treatment can include neurological problems, secondary cancers and maldevelopment of bones and muscles.

[0012] Monoclonal antibodies that target specific antigens are becoming increasingly prevalent in oncology. The differences in their mode of action compared to traditional cytotoxic therapies have made them valuable front-line agents as shown with rituximab (leukemia and lymphoma), cetuximab (bowel and head / neck cancer), and trastuzumab (breast and stomach cancer). The disialoganglioside GD2, a glycosphingolipid, has been shown to be expressed on the cell surface of nervous tissue but is rarely expressed in normal tissues. Additionally, GD2 is uniformly expressed in neuroblastomas and to varying degrees other cancer tissues including melanomas, bone and soft-tissue sarcomas, small-cell lung cancer, renal cell carcinoma, and brain tumors, Ewing sarcoma, breast cancer, desmoplastic small round cell tumor and retinoblastoma. As such, GD2 represents an attractive target for therapeutic development.

[0013] New therapeutic protocols are required for patients with GD2-positive cancers that have metastasised. The present disclosure intends to provide new and inventive protocols that can bring improved outcomes to these patients, such as improved response to treatment, overcoming refractory status, reduced cancer load, reduced number of metastatic sites, better quality of life or increased survival time.

[0014] All documents referred to herein are incorporated by reference in their entirety.

[0015] The listing or discussion of an apparently prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge. SUMMARY OF INVENTION

[0016] An object of the invention is to provide a treatment for metastasis of a GD2-positive cancer in a patient in need thereof.

[0017] In a first aspect, the present invention provides a method of treating metastasis of a GD2-positive cancer in a patient in need thereof, the method comprising administering an anti-GD2 antibody, or fragment thereof, to the patient in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites.

[0018] In a second aspect, the present invention provides an anti-GD2 antibody for use in a method of treating metastasis in a GD2-positive cancer in a patient by administering anti-GD2 antibody to the patient in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites.

[0019] In a third aspect, the present invention provides a use of anti-GD2 antibody in the preparation of a medicament for treating metastasis in a GD2-positive cancer in a patient, wherein the medicament is for administration to the patient in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites.

[0020] In a fourth aspect, the present invention provides a use of anti-GD2 antibody for treating metastasis in a GD2-positive cancer in a patient in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites.

[0021] DETAILED DESCRIPTION

[0022] As described above, the present invention uses anti-GD2 antibodies in combination with SBRT at one or more metastatic sites to treat metastasis in a GD2 positive (GD2+) cancer.

[0023] The molecular properties of anti-GD2 monoclonal antibodies which have been developed clinically, and are derived from 14G2a or 3F8, are described in Sterner et al75. Antibody 14G2a has been developed as chimeric (murine / human) forms known as ch!4.18, in particular, dinutuximab beta (Qarziba®) and dinutuximab (Unituxin®).

[0024] Fragment formats based upon chl4.18 have been reported and include minibodies and scFvs which after conjugation with MMAE or MMAF, can induce cytotoxic and cytostatic effects in GD2+ neuroblastoma cell lines. An independently generated murine antibody 3F8, humanized as naxitamab, has been approved for patients with relapsed or refractory high-risk neuroblastoma.(73)According to Sterner (Cell Reports, supra), humanized 3F8 has an apparent kD of 7.7 nM for binding to GD2, a binding preference for GD2 versus the related glycan structure GT2 of 1500, and a binding preference for GD2 versus the related glycan structure GQ2 of 200, whereas dinutuximab (Unituxin®) has an apparent kD of 60 nM for binding to GD2, a binding preference for GD2 versus GT2 of >5000 and a binding preference for GD2 versus GQ2 of 1000. These differences reflect the different binding regions of the antibodies. Dinutuximab beta (Qarziba®), which is produced in Chinese Hamster Ovary (CHO) cells, and dinutuximab (Unituxin®), which is produced in SP2 / 0 murine hybridoma cells, differ in their glycosylation patterns. Dinutuximab beta has a single N-linked glycosylation site (Asn 293), and mass spectrometry analysis revealed that the heavy chain contains the typical IgG diantennary fucosylated N-glycans with 0, 1, or 2 galactose residues, with a smaller fraction of glycans with sialic acid and oligomannose residues, and no Gal-o-1,3 Gal, typical for IgG expression in CHO cells (European Public Assessment Report (EPAR) of the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) for Dinutuximab beta Apeiron (EMA / 263814 / 2017, 23 March 2017). A humanized version of chl4.18 known as hul4.18K322A is described in W02005 / 070967 and has a point mutation in the Fc region in order to reduce complement-dependent cytotoxicity (CDC) but still maintain antibody-dependent cellular cytotoxicity (ADCC). The reduction in CDC is considered to result in reduced pain associated with the antibody treatment. However, it is shown in US 9,777,068B2 that the cytolysis capacity of an anti-GD2 antibody as measured by a CDC assay is essential for the anti-tumour effect.

[0025] Dinutuximab beta, also referred to as chl4.18 / CHO or APN311 is licensed in the European Union (EU) subject to additional monitoring as Qarziba® and is administered at 10 mg / m2 / day as an 8-hour or 24-hour infusion (Dinutuximab Beta Investigator's Brochure. Version 3.0 dated 14 May 2019). Dinutuximab beta is indicated for the treatment of high-risk neuroblastoma in patients aged 12 months and above, who have previously received induction chemotherapy and achieved at least a partial response, followed by myeloablative therapy and stem cell transplantation, as well as patients with history of relapsed or refractory neuroblastoma, with or without residual disease. Dinutuximab beta is also authorised as a medicinal product in Australia and Israel. Various patents cover methods of using Dinutuximab beta, particularly US 9,777,068 B2 (see also WO 2013 / 189554 Al) which discloses a continuous intravenous infusion regimen which reduces the side-effect of pain; and US 9,840,566 B2 and US 10,294,305 B2 which disclose treatment regimens in which IL-2 is not administered in the same treatment cycle or overall treatment period.

[0026] Individual GD2+ antibody therapy, whilst significantly improving survival rates for high-risk neuroblastoma patients, is accompanied by a substantial toxicity burden. A 2020 study using Dinutuximab (Unituxin®) showed that 73% of patients experienced toxicities of grade 4. Commonly reported effects included pain, fever, coughing, edema, and liver enzyme abnormalities. As such supplementing chemotherapy regimens with anti-GD2+ immunotherapies can result in potentially unacceptable patient toxicity profiles. There remains a need to improve GD2+ immunotherapy for patients with relapsed or refractory neuroblastoma without chemotherapy supplementation.

[0027] The present invention provides methods of treating metastasis in GD2 positive cancers, such as relapsed or refractory neuroblastoma in a patient and compositions for use in the methods. Neuroblastomas are cancers that start in early nerve cells (called neuroblasts) of the sympathetic nervous system, and they can be found anywhere along this system. Most primary tumors (65%) occur within the abdomen with at least half of these arising in the adrenal medulla. Other common sites of disease include the neck, chest, pelvis and spine. Presenting signs and symptoms are highly variable and dependent on site of primary tumor as well as the presence or absence of metastatic disease and / or paraneoplastic syndromes.

[0028] International Neuroblastoma Risk Group Staging System (INRGSS) is a clinical classification system that is determined prior to any treatment, including surgery, based on preoperative imaging. It classifies according to 2 stages of localized (LI and L2) and 2 stages of metastatic disease (M and MS).75A new International Neuroblastoma Risk Group (INRG) classification system has been proposed in 2009 with 4 broad categories —very low risk, low risk, intermediate risk, and high risk — based on the assessment of the following prognostic factors: age at diagnosis (2 cutoffs, 12 and 18 months), INRG tumour stage (LI, L2, M, MS), histologic category, grade of tumour differentiation, DNA ploidy (hyperploidy / diploidy), MYCN oncogene status (amplified or not), aberrations at chromosome llq (presence / absence).1(This system uses combinations of the seven prognostic risk factors to define 16 pretreatment groups stratified by the prognostic markers within four categories, namely very low-, low-, intermediate- and or high-risk group, the categories based on the 5-year event-free survival (EFS) rates of the 16 pretreatment groups. The pretreatment groups (labeled A to R) and risk categories are summarized in Table I.4 Table 1 : Neuroblastoma pretreatment groups and risk categories

[0029] Abbreviations: GN, Neuroblastoma Risk Group; NA, not amplified, Hp, Hyperdiploid; Dp, Diploid.

[0030] 4925-6375-4071 , v. 1

[0031] Stereotactic Body Radiation Therapy (SBRT) is a high precision radiotherapy technique used in the treatment of small to moderate extra-cranial tumours. The technique utilises radiotherapy from different angles around the body, therefore exposing the tumour to a high dose of radiation whilst the surrounding tissue receives a relatively lower dose. SBRT therapy can deliver an optimal dosage of radiation over a shorter period and requires no hospitalisation in contrast to conventional radiation therapy. Recent evidence suggests that SBRT therapy assists in enhancing immune surveillance of tumors.(8'9)SBRT treatment causes increased exposure of the immune system to tumour antigen-stimulating T-cell activation, while also increasing vascular permeability and altering the tumour microenvironment eliciting a favourable antitumor immune response. This can improve treatment response within and potentially outside of the irradiated field. Respective studies have suggested that patients treated with prior radiation therapy experienced greater benefit from immunotherapy. In a recent phase 1 study, prior radiation therapy was shown to significantly improve survival after treatment with pembrolizumab.(74)

[0032] Post-consolidation chimeric anti-GD2 monoclonal antibody (dinutuximab) with cytokines and isotretinoin has led to significant improvement in the survival of children with high-risk neuroblastoma.11Retrospective analysis also demonstrates that there may be improved survival with the addition of dinutuximab beta versus isotretinoin alone in the post-consolidation setting among patients with high-risk neuroblastoma.15Dinutuximab combined with irinotecan and temozolomide has also been shown to be effective in the setting of relapsed / refractory disease, with a response rate of ~ 40%.13- 14

[0033] As discussed above, there is an unmet need for improved treatments for metastasis of a GD2-positive cancer in a patient in need thereof, especially in neuroblastoma. The present invention relies on the use of an anti-GD2 antibody (or a fragment thereof), such as but not limited to dinutuximab beta, to prevent, treat, inhibit, or reduce metastasis of a GD2-positive cancer or the recurrence thereof, in patients. These anti- GD2 antibodies (or fragments thereof), such as dinutuximab beta, are to be used in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites.

[0034] While immunotherapy with anti-GD2 therapy has transformed the approach for treating high-risk neuroblastoma, a large subset of patients will not respond to anti-GD2 therapy. Pediatric cancers often demonstrate low mutational burden and are non-T cell-inflamed or "cold", with scarce tumor infiltrating lymphocytes amongst anti- inflammatory M2 tumor associated macrophages.15 17The inventors have surprisingly found that a potential approach to augment the activity of immunotherapy in this setting is by altering the tumor microenvironment through stereotactic body radiotherapy (SBRT).

[0035] These and other aspects of the disclosure are described in detail below.

[0036] Unless indicated otherwise, all technical and scientific terms used herein will have their common meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0037] It is contemplated that any method, use or treatment described herein can be implemented with respect to any other method, use or treatment described herein. All features disclosed herein in connection with any particular aspect are applicable to each of the other aspects, mutatis mutandis. In particular, all features disclosed herein in connection with the first aspect are applicable to each of the second to fourth aspects, mutatis mutandis. Other objects, features and advantages of the present disclosure will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure will become apparent to those skilled in the art from this detailed description.

[0038] The term "comprises" or "comprising" will take its usual meaning in the art, namely indicating that the component includes but is not limited to the relevant features (i.e. including, among other things). As such, the term "comprises" will include references to the component consisting essentially of (such as consisting of) the relevant features. The term "consists of" or "consisting of" will take its usual meaning in the art, namely indicating that the component includes and is limited to the relevant features.

[0039] The use of the word "a" or "an" when used in conjunction with the term "comprising" in the claims and / or the specification may mean "one," but it is also consistent with the meaning of "one or more," "at least one," and "one or more than one." The word "about" means plus or minus 5% of the stated number.

[0040] Where a numerical range is provided herein for any parameter, it is understood that all numerical subsets of that numerical range, and all the individual integer values contained therein, are provided as part of the invention. As used herein, the term "optionally" means that the subsequently described event(s) may or may not occur, and includes both event(s) which occur, and events that do not occur.

[0041] Methods of Treatment

[0042] The first aspect of the invention is a method of treating metastasis of a GD2-positive cancer in a patient in need thereof, the method comprising administering an anti-GD2 antibody, or fragment thereof, to the patient in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites.

[0043] The term "treatment", "treat" or "treating" as used herein, refers to therapeutic (curative) treatment including amelioration. Treatment also includes stopping the disease from developing or slowing further progression of the disease. For example, treatment may include preventing symptoms from worsening. The terms "prevention", "prevent" and "preventing" as used herein, refers to prophylaxis treatment i.e., action taken to prevent disease.

[0044] The terms "patient", "recipient" and "subject" are used interchangeably. By "a patient", "a subject" or "a recipient" the inventor(s) intend a human patient, subject or recipient. Typically, the patient is an adult i.e. > 18 years old at the commencement of the treatment. Alternatively, the patient may be a paediatric patient i.e. < 18 years old at the commencement of the treatment.

[0045] In a preferred embodiment of any of the aspects of the invention, the subject is a human.

[0046] In the context of this invention, "in combination" means that both the anti-GD2 antibody and SBRT are administered in combination as a treatment to the patient, which may be referred to as a combination therapy. By "in combination" or "combination therapy" the inventor(s) do not necessarily mean that the antibody is administered at the same time as the SBRT.

[0047] GD2-positive Cancer

[0048] The methods of the invention are for treating metastasis of a GD2-positive cancer. A GD2-positive cancer is a cancer which expresses or overexpresses GD2. "GD2" may also be referred to as "Ganglioside G2". GD2 is a disialoganglioside which may be expressed on tumours of neuroectodermal origin, including human neuroblastoma and melanoma, and typically has highly restricted expression on normal (i.e. non- cancerous) tissues.

[0049] In the context of this invention, "metastasis" refers to the spread of cancer cells from the place where they first formed to another part of the body. In metastasis, cancer cells break away from the original (primary) tumor, travel through the blood or lymph system, and form a new tumor in other organs or tissues of the body.

[0050] When tumor cells metastasize, the new tumor may be called a secondary or metastatic tumor, and its cells are typically similar to those in the original or primary tumor. Metastasis is typically a key element in cancer staging systems. For example, in overall stage grouping, metastasis may place a cancer in Stage IV. The possibilities of curative treatment are typically reduced, or may be entirely removed, when a cancer has metastasised.

[0051] Examples of GD2-positive cancers include, but are not limited to, neuroblastoma, ganglioneuroblastoma, glioblastoma, medulloblastoma, astrocytoma, melanoma, small- cell lung cancer, desmoplastic small round cell tumor, osteosarcoma, rhabdomyosarcoma, or another soft tissue sarcoma. Preferably, the GD2-positive cancer is neuroblastoma. More preferably, the GD2-positive cancer is high-risk neuroblastoma.

[0052] In particular, the invention may be used to treat a GD2-positive cancer that is relapsed or refractory. Preferably, the relapsed or refractory GD2-positive cancer is relapsed or refractory neuroblastoma. In one embodiment, the patient suffers from primary refractory or relapsed high risk-neuroblastoma. The patient may have previously been treated with another therapy such as, for example, surgery, chemotherapy, radiation, stem cell transplantation, cytokine treatment (e.g. with IL-2 and / or GM-CSF) and / or retinoid treatment (e.g. with isotretinoin).

[0053] "Relapsed" means a cancer that has come back after a period of improvement (e.g., due to treatment), such as after a period of remission. There is no time limit on how long a cancer can be in a period of improvement or remission before a returning cancer is referred to as "relapsed", but typically the period of improvement or remission may be in the order of weeks, months, or years. For example, a patient with relapsed cancer may have already undergone initial treatment for the cancer, resulting in a period of improvement (such as a period with reduced symptoms of cancer, and / or an improved prognosis), and / or a period of partial or complete remission, followed by the return of the cancer (relapsed cancer). Remission means that the signs and / or symptoms of the cancer are reduced. Remission can be partial or complete. In a complete remission, all signs and symptoms of cancer may have disappeared, so that the cancer can no longer be detected in the patient. In partial remission, some signs and symptoms of cancer may be reduced and / or have disappeared, but some signs and / or symptoms may remain. A "relapsed" cancer may also be referred to as a "recurrent" cancer.

[0054] "Refractory" means a cancer that does not respond (primary refractory), or has stopped responding (secondary refractory), to treatment. "Primary refractory" refers to a patient who has never achieved a complete remission from previous treatments, and who was not in partial remission at the time of the last evaluation prior to commencing treatment according to the invention. Partial remission may have been achieved at some point for the primary refractory, but the patient may no longer be in partial remission. "Secondary refractory" refers to a cancer that has stopped responding to treatment (prior to commencing treatment according to the invention).

[0055] Relapsed neuroblastoma refers to the return of neuroblastoma in patients who have already undergone treatment for the disease and achieved partial or complete remission. Relapse is more common in neuroblastoma than in many other cancers.

[0056] Patients may be considered to have refractory neuroblastoma if at least one tumour does not respond to initial treatment.

[0057] Anti-GD2 Antibodies

[0058] By "antibody" the inventor(s) include substantially intact antibody molecules, as well as chimeric antibodies, humanised antibodies, human antibodies (wherein at least one amino acid is mutated relative to the naturally occurring human antibodies), single chain antibodies, bi-specific antibodies, antibody heavy chains, antibody light chains, homo-dimers and heterodimers of antibody heavy and / or light chains, and antigen binding fragments and derivatives of the same. The term also includes antibody-like molecules which may be produced using phage-display techniques or other random selection techniques for molecules. The term also includes all classes of antibodies, including IgG, IgA, IgM, IgD, and IgE. Also included for use in the invention are antibody fragments such as Fab, F(ab')2, Fv, Fab', scFv (single-chain variable fragment), or di-scFv and other fragments thereof that retain the antigen-binding site. Similarly, the term "antibody" includes genetically engineered derivatives of antibodies such as single-chain Fv molecules (scFv) and single-domain antibodies (dAbs).

[0059] Preferred antibodies are chimeric, such as mouse-human chimeric antibodies, CDR- grafted antibodies, humanised antibodies, or human antibodies. For example, the anti- GD2 antibody may be a chimeric, humanized or CDR grafted anti-GD2 antibody. In an embodiment, the anti-GD2 antibody is a chimeric anti-GD2 antibody. Although the antibody may be a polyclonal antibody, it is preferred if it is a monoclonal antibody, or that the antigen-binding fragment is derived from a monoclonal antibody. Suitable monoclonal antibodies may be prepared by known techniques, for example those disclosed in "Monoclonal Antibodies; A manual of techniques"77and in "Monoclonal Hybridoma Antibodies: Techniques and Application"78. The antibodies may be human antibodies in the sense that they have the amino acid sequence of human antibodies with specificity for GD2; however, it will be appreciated that they may be prepared using methods known in the art that do not require immunisation of humans. Suitable antibodies may be prepared from transgenic mice which contain human immunoglobulin loci, as described in "Complete humanization of the mouse immunoglobulin loci enables efficient therapeutic antibody discovery"79.

[0060] Suitably prepared non-human antibodies can be "humanised" in known ways, for example, by inserting the CDR regions of mouse antibodies into the framework of human antibodies. Chimeric antibodies are discussed in Neuberger et al80.

[0061] It will be appreciated by persons skilled in the art that the binding specificity of an antibody or antigen-binding fragment thereof is conferred by the presence of complementarity determining regions (CDRs) within the variable regions of the constituent heavy and light chains. As discussed below, in a particularly preferred embodiment of the antibodies and antigen-binding fragments, binding specificity for GD2 is conferred by the presence of one or more and typically all six of the CDR amino acid sequences defined herein.

[0062] Preferably, the antibody or antigen-binding fragment comprises an antibody Fc region. It will be appreciated by the skilled person that the Fc portion may be from an IgG antibody, or from a different class of antibody (such as IgM, IgA, IgD, or IgE). For example, the Fc region may be from an IgGl, IgG2, IgG3, or IgG4 antibody. Advantageously, however, the Fc region is from an IgGl antibody. It is preferred that the antibody or antigen-binding fragment is an IgG molecule, or is an antigen-binding fragment or variant of an IgG molecule. Anti-GD2 antibodies which may be used in the invention include, but are not limited to, dinutuximab, dinutuximab beta, and naxitamab. Fragments of any of these antibodies may also be used. Suitably, the anti-GD2 antibody or fragment is a chimeric, humanized or CDR grafted antibody or fragment thereof.

[0063] Naxitamab is FDA-approved for treatment of high-risk neuroblastoma in combination with GM-CSF for pediatric patients one year of age and older and adult patients with relapsed or refractory high-risk neuroblastoma in the bone or bone marrow demonstrating a partial response, minor response, or stable disease to prior therapy. Efficacy was evaluated in patients with relapsed or refractory neuroblastoma in the bone or bone marrow enrolled in two single-arm, open-label trials: Study 201 (NCT 03363373) and Study 12-230 (NCT 01757626).

[0064] Dinutuximab and dinutumximab beta are approved monoclonal antibodies for postconsolidation therapy in paediatric patients with high-risk neuroblastoma. Dinutuxmab is approved by the FDA and sold under the name Unituxin®. It is administered to high- risk neuroblastoma patients who achieve at least a partial response to prior first-line multiagent, multimodality therapy. Administration is performed intravenously over 10 or 20 hours or 4 consecutive days for up to 5 cycles. Efficacy was evaluated in a paediatric study of 226 patients in a two single-arm trial. The treatment is given in conjunction with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-2 and isotretinoin.

[0065] Dinutuximab beta is approved in Europe and approval is pending in the US and other countries. It is also used as a second line treatment for children with high-risk neuroblastoma; it was tested and is used with a longer and slower dosing regime, and is given on its own, although it may be combined with IL-2 if a stronger immune response is needed.

[0066] Nucleotide sequences encoding dinutuximab and dinutuximab beta are provided below as SEQ ID NO: 1 and SEQ ID NO: 2. The skilled person will appreciate that these sequences can be inserted into any suitable expression vector for production of the antibody.

[0067] SEQ ID NO: 1 (Light chain DNA sequence):

[0068] ATGGAAGCCCCAGCGCAGCTTCTCTTCCTCCTGCTACTCTGGCTCCCAGATACCACTGGAGA AATAGTGATGACGCAGTCTCCAGCCACCCTGTCTGTGTCTCCAGGGGAAAGAGCCACCCTCT CCTGCAGATCTAGTCAGAGTCTTGTACACCGTAATGGAAACACCTATTTACATTGGTACCTGC AG AAG CCAG G CCAGTCTCCAAAG CTCCTG ATTCACAAAGTTTCCAACCG ATTTTCTG G G GTC CCAGACAGGTTCAGTGGCAGTGGATCAGGGACAGATTTCACACTCAAGATCAGCAGAGTGG AG G CTG AG G ATCTG G G AGTTTATTTCTGTTCTCAAAGTACACATGTTCCTCCG CTCACGTTCG GTG CTG G G ACCAAG CTG GAG CTG AAACG AACTGTG G CTG CACCATCTGTCTTCATCTTCCCG CCATCTGATGAGCAGTTGAAATCTGGAACTGCCTCTGTTGTGTGCCTGCTGAATAACTTCTAT CCCAGAGAGGCCAAAGTACAGTGGAAGGTGGATAACGCCCTCCAATCGGGTAACTCCCAGG AGAGTGTCACAGAGCAGGACAGCAAGGACAGCACCTACAGCCTCAGCAGCACCCTGACGCT GAGCAAAGCAGACTACGAGAAACACAAAGTCTACGCCTGCGAAGTCACCCATCAGGGCCTG AG CTCG CCCGTCACAAAG AG CTTCAACAG G G G AG AGTGTTAG

[0069] SEQ ID NO: 2 (Heavy chain DNA sequence):

[0070] ATGGGATGGACCTGGATCTTTATTTTAATCCTGTCGGTAACTACAGGTGTCCACTCTGAGGTC CAACTGCTGCAGTCTGGACCTGAGCTGGAGAAGCCTGGCGCTTCAGTGATGATATCCTGCAA GGCTTCTGGTTCCTCATTCACTGGCTACAACATGAACTGGGTGAGGCAGAACATTGGAAAGA GCCTTGAATGGATTGGAGCTATTGATCCTTACTATGGTGGAACTAGCTACAACCAGAAGTTC AAGGGCAGGGCCACATTGACTGTAGACAAATCGTCCAGCACAGCCTACATGCACCTCAAGA GCCTGACATCTGAGGACTCTGCAGTCTATTACTGTGTAAGCGGAATGGAGTACTGGGGTCAA GGAACCTCAGTCACCGTCTCCTCAGCCTCCACCAAGGGCCCATCGGTCTTCCCCCTGGCACC CTCCTCCAAGAGCACCTCTGGGGGCACAGCGGCCCTGGGCTGCCTGGTCAAGGACTACTTC CCCGAACCGGTGACGGTGTCGTGGAACTCAGGCGCCCTGACCAGCGGCGTGCACACCTTCC CGGCTGTCCTACAGTCCTCAGGACTCTACTCCCTCAGCAGCGTGGTGACCGTGCCCTCCAGC AGCTTGGGCACCCAGACCTACATCTGCAACGTGAATCACAAGCCCAGCAACACCAAGGTGG ACAAG AG AGTTG AG CCCAAATCTTGTG ACAAAACTCACACATG CCCACCGTG CCCAG CACCT G AACTCCTG G G G G G ACCGTCAGTCTTCCTCTTCCCCCCAAAACCCAAG G ACACCCTCATG AT CTCCCGG ACCCCTG AG GTCACATG CGTG GTGGTG G ACGTG AG CCACG AAG ACCCTG AGGTC AAGTTCAACTGGTACGTGGACGGCGTGGAGGTGCATAATGCCAAGACAAAGCCGCGGGAG GAGCAGTACAACAGCACGTACCGTGTGGTCAGCGTCCTCACCGTCCTGCACCAGGACTGGC TG AATG G CAAG G AGTACAAGTG CAAG GTCTCCAACAAAG CCCTCCCAG CCCCCATCG AG AA AACCATCTCCAAAGCCAAAGGGCAGCCCCGAGAACCACAGGTGTACACCCTGCCCCCATCC CGGGAGGAGATGACCAAGAACCAGGTCAGCCTGACCTGCCTGGTCAAAGGCTTCTATCCCA GCGACATCGCCGTGGAGTGGGAGAGCAATGGGCAGCCGGAGAACAACTACAAGACCACGC CTCCCGTGCTGGACTCCGACGGCTCCTTCTTCCTCTATAGCAAGCTCACCGTGGACAAGAGC AGGTGGCAGCAGGGGAACGTCTTCTCATGCTCCGTGATGCATGAGGCTCTGCACAACCACT ACACGCAGAAGAGCCTCTCCCTGTCCCCGGGTAAATGA Protein sequences of the light (SEQ ID NO: 3) and heavy (SEQ ID NO: 4) chains of dinutuximab or dinutuximab beta including signal peptide sequence are shown below. The signal peptide sequence (shown in bold underlined font) is removed during post translational processing and does not form part of the final recombinant protein, which therefore has a light chain sequence of SEQ ID NO: 18 and a heavy chain sequence of SEQ ID NO: 19. In any event, the skilled person will appreciate how to determine the identity of the signal peptide sequence and the positioning of the cleavage site. For example, the cleavage site for the light chain sequence (SEQ ID NO: 3) may be between positions 20 and 21 (Gly20-Glu21); the cleavage site for the heavy chain sequence (SEQ ID NO:4) may be between positions 19 and 20 (Serl9-Glu20). Alternative signal peptide sequences may also be used.

[0071] SEQ ID NO:3 (Light chain protein sequence with signal peptide):

[0072] MEAPAOLLFLLLLWLPDTTGEIVMTOSPATLSVSPGERATLSCRSSOSLVHRNGNTYLHWYL QKPGQSPKLLIHKVSNRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYFCSQSTHVPPLTFGA GTKLELKRTVAAPSVFIFPPSDEQLKSGTASWCLLN NFYPREAKVQWKVDNALQSGNSQESVT EQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC

[0073] SEQ ID NO:4 (Heavy chain protein sequence with signal peptide):

[0074] MGWTWIFILILSVTTGVHSEVOLLOSGPELEKPGASVMISCKASGSSFTGYN MNWVRONIG KSLEWIGAIDPYYGGTSYNQKFKGRATLTVDKSSSTAYM HLKSLTSEDSAVYYCVSGMEYWGQ GTSVTVSS ASTKG PSVFP LAPSS KSTSG GTAALG CLVKDYFPE PVTVS W N SG ALTSG VHTFPAV LQSSGLYSLSSWTVPSSSLGTQTYICNVNHKPSNTKVDKRVEPKSCDKTHTCPPCPAPELLGGP SVFLFPPKPKDTLMISRTPEVTCVWDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRV VSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLT CLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVM H EALHN HYTQKSLSLSPGK

[0075] SEQ ID NO:18 (Final light chain protein sequence):

[0076] EIVMTQSPATLSVSPGERATLSCRSSQSLVHRNGNTYLHWYLQKPGQSPKLLIHKVSN RFSGVP DRFSGSGSGTDFTLKISRVEAEDLGVYFCSQSTHVPPLTFGAGTKLELKRTVAAPSVFIFPPSDE QLKSGTASWCLLNN FYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADY EKH KVYACEVTHQG LSS PVTKSFN RG EC SEQ ID NO:19 (Final heavy chain protein sequence):

[0077] EVQLLQSGPELEKPGASVMISCKASGSSFTGYNMNWVRQNIGKSLEWIGAIDPYYGGTSYNQK FKGRATLTVDKSSSTAYMHLKSLTSEDSAVYYCVSGMEYWGQGTSVTVSSASTKGPSVFPLAP SSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSWTVPSSSLG TQTYICNVNHKPSNTKVDKRVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEV TCVWDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRWSVLTVLHQDWLNGKEYKC KVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQ PENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK Table 2 shows some exemplary CDR sequences of antibodies that may be suitable for the invention. The sequences are given according to three different definitions that the skilled person is aware how to use. The Kabat definition is based on sequence variability. The Chothia definition is based on the location of the structural loop regions. The IMGT numbering scheme was originally based on alignment of germ-line V genes, spanning from FR1 to the beginning of the CDR3, and was later extended to cover the entire variable region; the numbering runs from 1 to 128 based on the V- gene sequence alignment, with an insertion point only between positions 111 and 112 in the CDR3 for lengths exceeding 13 amino acids.

[0078] Table 2: CDR sequences for variable heavy (VH) and variable light (VL) chain regions of an antibody (dinutuximab or dinutuximab beta) according to three different definitions (IMGT, Kabat, Chothia) Suitable antibodies and fragments are also described in WO 2013 / 189554 Al.

[0079] Suitably, the antibody or fragment is a chimeric, humanized or CDR grafted antibody or fragment thereof comprising a light chain variable region in which CDR1, CDR2, and CDR3 comprise the amino acid sequences SEQ ID NO: 5, SEQ ID NO: 6 and SEQ ID NO: 7, respectively; and a heavy chain variable region in which CDR1, CDR2, and CDR3 comprise the amino acid sequences SEQ ID NO: 8, SEQ ID NO: , 9 and SEQ ID NO: 10, respectively, and a constant region derived from a human IgG antibody or a humanised IgG antibody. Suitably, the antibody or fragment is a chimeric, humanized or CDR grafted antibody or fragment thereof comprising a light chain variable region in which CDR1, CDR.2, and CDR.3 comprise the amino acid sequences SEQ ID NO: 11, SEQ ID NO: 12 and SEQ ID NO: 7, respectively; and a heavy chain variable region in which CDR.1, CDR2, and CDR3 comprise the amino acid sequences SEQ ID NO: 13, SEQ ID NO:, 14 and SEQ ID NO: 15, respectively, and a constant region derived from a human IgG antibody or a humanised IgG antibody.

[0080] Suitably, the antibody or fragment is a chimeric, humanized or CDR grafted antibody or fragment thereof comprising a light chain variable region in which CDR1, CDR2, and CDR3 comprise the amino acid sequences SEQ ID NO: 11, SEQ ID NO: 12 and SEQ ID NO: 7, respectively; and a heavy chain variable region in which CDR1, CDR2, and CDR3 comprise the amino acid sequences SEQ ID NO: 16, SEQ ID NO: 17 and SEQ ID NO: 15, respectively, and a constant region derived from a human IgG antibody or a humanised IgG antibody.

[0081] Optionally, the antibody is dinutuximab beta. The protein component of Dinutuximab beta consists of 2 light chains (220 amino acids) and 2 heavy chains (443 amino acids) and is of the IgGl subclass. The monoclonal antibody incorporates human constant regions for the heavy chain IgGl and the kappa light chain, along with the mouse variable regions targeted specifically against human GD2. The relative molecular mass of the intact antibody is approximately 150,000 daltons. The encoding nucleotide sequences and the amino acid sequences of chimeric anti-GD2 antibody dinutuximab beta are also provided in WO 2013 / 189554 Al (SEQ ID NOs: l-4 therein). Methods of manufacture and formulation of dinutuximab beta for clinical use are described in the European Public Assessment Report (EPAR) of the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) for Dinutuximab beta Apeiron (EMA / 263814 / 2017, 23 March 2017).

[0082] A preparation comprising a dinutuximab beta may further comprise salts and WFI. In one embodiment, the preparation comprising dinutuximab beta may further comprise a buffer, e.g., phosphate-buffered saline, comprising said salts and WFI. A preparation comprising dinutuximab beta may further comprise stabilizing agents, preservatives and other carriers or excipients. The preparation comprising a dinutuximab beta may be freeze-dried and reconstituted for use. In one embodiment, the preparation comprising dinutuximab beta does not comprise preservatives and other excipients. The preparation comprising dinutuximab beta may be added to an infusion bag, e.g., an infusion bag containing 100 mL NaCI 0.9% and 5 mL human serum albumin 20%.

[0083] Properties of dinutuximab beta are further shown in Table 3.

[0084] Table 3: Properties of dinutuximab beta

[0085] Stereotactic Body Radiotherapy (SBRT)

[0086] Stereotactic body radiotherapy (SBRT) is a non-invasive treatment that can precisely deliver high radiation doses to small targets, preferably sparing healthy tissues. Stereotactic body radiotherapy (SBRT) is a type of radiation therapy that uses multiple beams of energy (fractions). SBRT gives radiotherapy from many different angles around the body to target one or more metastatic sites. The beams meet at the one or more metastatic sites. This means the one or more tumours receive a high dose of radiation and the tissues around them receive a much lower dose, which reduces the risk of side effects.

[0087] SBRT may involve the use of sophisticated image guidance that pinpoints the exact three-dimensional location of a tumor so that the radiation can be more precisely delivered to the one or more metastatic sites. SBRT typically uses 3D or 4D imaging and one or more highly focused radiation beams (one or more fractions) to send high doses of radiation to the area to be treated (e.g. to one or more metastatic sites). SBRT may be administered to each metastatic site, but SBRT does not have to be delivered to every metastatic site present in the patient's body in the treatment described herein.

[0088] Each dose of SBRT may be administered in two or more fractions. The number of fractions may be selected depending on the characteristics of the patient, the characteristics (e.g. size, diameter, location) and number of metastatic sites, and the treatment that the patient has already been administered or is simultaneously being administered. For example, the SBRT may be administered at one or more metastatic sites in 5 fractions or fewer, preferably 3, 4, or 5 fractions, more preferably 5 fractions. Each fraction may or may not have the same strength of radiation dosage.

[0089] SBRT typically may be used to treat tumors, including but not limited to those in the lungs, spine, liver, neck, lymph nodes and / or other soft tissues. SBRT is sometimes called stereotactic ablative radiotherapy (SABR). When used on the brain, it may be called stereotactic radiosurgery (SRS). "SBRT", "SRT", "stereotactic body radiotherapy" and "stereotactic radiotherapy" are used interchangeably throughout this application.

[0090] Stereotactic body radiotherapy can treat areas of the body that have had radiotherapy before. For example, if a patient has had radiotherapy to their pelvis, they usually can't have radiotherapy to the same area again. As stereotactic treatment is so precise, it may mean re-treatment with SBRT to the same area is possible.

[0091] By "one or more metastatic sites", the inventor(s) mean one or more sites in the patient's body where metastasis has occurred, for example one or more metastatic tumors or metastatic tumor lesions. The skilled person would be able to determine whether a metastatic tumor lesion is suitable for SBRT.

[0092] The patient preferably has at least one metastatic tumor lesion suitable for SBRT. More preferably, the patient has at least one metastatic tumor lesion in the lung, liver, mediastinal / cervical nodes, spinal / paraspinal / osseous, or abdominal-pelvic (lymph node / adrenal gland) region suitable for SBRT. Alternatively, the patient has at least one metastatic tumor lesion in the mediastinal / cervical nodes, spinal / paraspinal / osseous, or abdominal-pelvic (lymph node / adrenal gland) region suitable for SBRT.

[0093] The patient may have at least one metastatic tumour lesion that has a diameter > (greater than or equal to) 10 mm in at least one dimension. The diameter of each of the one or more metastatic tumour lesions may be measured by conventional methods for measuring tumour lesions, for example by using an MRI or CT scan. The patient may have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more metastatic tumour lesions with a diameter > (greater than or equal to) 10 mm in at least one dimension.

[0094] By "at least one dimension" the inventor(s) mean that one dimension has a diameter of greater than or equal to 10 mm, and diameters around one or more other axes of the lesion may also be greater than or equal to 10 mm. Alternatively, diameters around one or more other axes of the lesion may not be greater than or equal to 10 mm

[0095] By "a diameter > 10 mm" the inventor(s) mean a metastatic tumor lesion with a diameter of greater than or equal to 10 mm, such as with a diameter of 10mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 13 mm, 14 mm, 15 mm and so on. "Greater than or equal to" and ">" are used interchangeably throughout the application.

[0096] The patient may have at least one metastatic tumor lesion that is a discrete lymph node with a diameter greater than or equal to 15 mm on its short axis. The diameter may be measured by conventional methods for measuring tumour lesions, for example by using an MRI or CT scan.

[0097] To be considered pathologically enlarged and measurable, a metastatic lymph node may be > 15 mm in short axis when assessed by CT or MRI scan (CT scan slice thickness is recommended to be no greater than 5 mm). At baseline and in follow-up, the short axis of a discreet lymph node may be measured and followed as per RECIST criteria. Patients with neuroblastoma may have conglomerate masses of non-discrete lymph nodes (such as multiple contiguous retroperitoneal nodes). When a short axis of a discreet node cannot be identified, a lymph node conglomerate may be measured using the longest diameter of the composite lesion. Tracer avidity of metastatic nodes may be recorded at baseline and during disease evaluations.

[0098] The patient may have at least one metastatic tumor lesion that is MIBG avid or demonstrates increased FDG uptake on PET scan.

[0099] MIBG avidity is an adverse prognostic factor in neuroblastoma. Patients with MIBG avid disease typically have inferior clinical outcomes. "MIBG" and "Meta-Iodo-Benzyl- Guanidine" are used interchangeably throughout the application. MIBG is a type of internal radiotherapy. Internal radiotherapy means giving radiotherapy to the cancer cells (tumours or metastatic sites) from inside the body. Internal radiotherapy may give a high dose of radiation to the tumour, but little to the surrounding (healthy) tissues.

[0100] I-MIBG uses a radioactive form of iodine, such as iodine 123 (I123) or iodine 131 (I131), preferably iodine 123 (I123).131I-MIBG was approved by the FDA as a diagnostic agent in 1994. However, because of the properties of131I-MIBG including a higher energy imaging photon of 364 kEV (compared to 159 kEV in I123), and a longer half-life,123I- MIBG has higher image quality with lower scatter.

[0101] 123I-MIBG was approved by the FDA in 2008 for imaging of pediatric neuroblastoma. The effectiveness of123I-MIBG in a diagnostic capacity is well known. The sensitivity ranges from 88 to 93% and specificity ranges from 83 to 92%. Some cancers, such as approximately 10% of neuroblastomas, are not MIBG avid and therefore may require alternative imaging with fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography (PET) or technetium 99m-methylene diphosphonate (99mTc- MDP) bone scintigraphy. Suitably, FDG-PET imaging may be used for MIBG non-avid tumours, such as123I-MIBG non-avid tumours.

[0102] "FDG" and "fluorodeoxyglucose" are used interchangeably throughout the application. "PET" and "positron emission tomography" are used interchangeably throughout the application.

[0103] A patient may have a primary metastatic site. If the patient has only one metastatic site then this may be considered as the primary metastatic site. In patients with more than one metastatic site, the primary metastatic site may be identified as a measurable lesion > 10 mm in diameter as assessed by cross sectional imaging (for example by CT or MRI scan), for example it may be the measurable lesion with the greatest diameter as assessed by cross sectional imaging. Site measurements may be recorded in millimeters (or decimal fractions of centimeters). The longest diameter of a tumor (e.g. a primary site) may be recorded at baseline. Serial measurements of a tumor (e.g. a primary site) may include assessment of tumor size in the same orthogonal plane at the time of each evaluation.58In patients with bilateral adrenal lesions, response can be based on the sum of the longest dimensions of both adrenal lesions, unless biopsy proves one to be ganglioneuroma rather than neuroblastoma / ganglioneuroblastoma. In patients with multi-focal non-adrenal disease, the largest tumor may be considered as the primary tumor.

[0104] Tracer avidity (123I-MIBG or FDG-PET) in a site, such as the primary site, may be recorded at baseline. The scan appropriate for serial disease assessments may be used at each disease re-evaluation time point (e.g.,123I-MIBG avid lesions, such as I-MIBG avid primary lesions, may be followed using123I-MIBG scans during treatment according to the invention).

[0105] The SBRT may be administered in a dose of from 10 Gy to 50 Gy per site. For example, the SBRT dose may be 10 Gy, 12.5 Gy, 15 Gy, 17.5 Gy, 20 Gy, 22.5 Gy, 25 Gy, 27.5 Gy, 30 Gy, 35 Gy, 40 Gy, 45 Gy or 50 Gy at one or more sites.

[0106] By "Gy" the inventor(s) mean gray which is the international system (SI) unit of radiation dose, expressed as absorbed energy per unit mass of tissue. 1 Gy = 1 Joule / kilogram = 100 rad. The SBRT dose may be different between two or more sites. For example, the SBRT dose may be 10 Gy, 12.5 Gy, 15 Gy, 17.5 Gy, 20 Gy, 22.5 Gy, 25 Gy, 27.5 Gy, 30 Gy, 35 Gy, 40 Gy, 45 Gy or 50 Gy at one site, and a different dose selected from 10 Gy, 12.5 Gy, 15 Gy, 17.5 Gy, 20 Gy, 22.5 Gy, 25 Gy, 27.5 Gy, 30 Gy, 35 Gy, 40 Gy, 45 Gy and 50 Gy at any other sites. If there are three or more sites, then the same dose may be administered at two sites and a different dose may be administered at a third site. If there are four or more sites, then the same dose may be administered at two sites and a different dose may be administered at a third and / or fourth site.

[0107] The SBRT dose may be the same at two or more sites, for example the SBRT dose may be 10 Gy, 12.5 Gy, 15 Gy, 17.5 Gy, 20 Gy, 22.5 Gy, 25 Gy, 27.5 Gy, 30 Gy, 35 Gy, 40 Gy, 45 Gy or 50 Gy at each site.

[0108] The SBRT dose may be chosen based on the anatomic site of metastatic disease. For example, the SBRT dose to a metastatic site (tumour) in the lung, liver, abdominal, pelvic, mediastinal, thoracic (axillary or cervical) may be higher than a dose for a spinal, paraspinal, and / or osseous metastatic site. In particular, the SBRT dose, such as an initial SBRT dose, administered to a metastatic site (tumour) in the lung, liver, abdominal, pelvic, mediastinal, thoracic (axillary or cervical), and / or lymph node may be 25 Gy, optionally administered as a fraction per day for 5 consecutive days (5 daily fractions). The SBRT dose, such as an initial SBRT dose, to a spinal, paraspinal, and / or osseous metastatic site may be 20 Gy, optionally administered as a fraction per day for 5 consecutive days.

[0109] The SBRT may be administered at an initial dose and one or more subsequent doses may be administered at a reduced dose. The dose may be reduced according to tolerance by the patient. Similarly to the initial dose, the reduced dose may be chosen according to the location of the one or more metastatic sites. In particular, the SBRT dose, such as a subsequent reduced SBRT dose, administered to a metastatic site (tumour) in the lung, liver, abdominal, pelvic, mediastinal, thoracic (axillary or cervical), and / or lymph node may be 20 Gy, optionally administered as a fraction per day for 5 consecutive days. The SBRT dose, such as a subsequent reduced SBRT dose, to a spinal, paraspinal, and / or osseous metastatic site may be 17.5 Gy, optionally administered as a fraction per day for 5 consecutive days.

[0110] The SBRT at the one or more metastatic sites may be completed within a total period of up to 1 week. The SBRT at the one or more metastatic sites may be completed within a total period of up to 5 days. In this context, by "total period" the inventor(s) mean the period of time in one treatment cycle in which all of the SBRT is administered to the patient. For example, if SBRT is administered for 2 consecutive days, followed by 2 days of no administration of the SBRT, then the total period for that cycle for SBRT is 2 days. In another example, if SBRT is administered for 2 consecutive days, followed by 2 days of no administration of the SBRT, followed by administration of SBRT for 2 consecutive days then the total period for that treatment cycle for SBRT is 6 days (i.e. within 1 week). Preferably, the SBRT is administered over five consecutive days in a cycle, and so the total period per cycle is preferably 5 days. The total period may be reduced over subsequent treatment cycles.

[0111] Patients may be administered SBRT to one or more (preferably to 1, 2, 3, or 4) metastatic lesions over the course of 1 week. For example, the SBRT at all of the one or more metastatic sites may be completed within a total period of up to 1 week, preferably up to 5 or 6 days. Alternatively, the SBRT may not be administered to all of the one or more metastatic sites, even if they are all suitable for SBRT.

[0112] The term "treatment cycle" as used herein means a course of one or more treatments or treatment periods that is repeated on a regular schedule and may encompass a period of rest. The treatment cycle may be repeated, either identically or in an amended form, e.g., with a different dose or schedule, or with different additional treatments. For example, a treatment cycle according to the invention may include administration of an anti-GD2 antibody and SBRT to a patient in need thereof. A "treatment interval" is the interval between starting and completing a treatment cycle.

[0113] The "overall treatment time" means the time period comprising all treatment cycles. As described above, treatment cycles may comprise time periods of no treatment (intervals in which no treatment is administered to the patient, i.e., no chemotherapy, no antibody, no SBRT, no other drug). Thus, as used herein, the overall treatment time may also comprise said intervals of no treatment within treatment cycles. For example, if the patient receives 8 treatment cycles of 10 days, then the overall treatment time is 80 days. The overall treatment time may comprise at least 1, or 2 or more, cycles, such as up to 16 cycles. In one embodiment, the overall treatment time comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 cycles.

[0114] The term "antibody treatment period" as used herein means the time period over which the anti-GD2 antibody is administered according to the invention. The antibody treatment period comprises or consists of all the antibody treatment days within a treatment cycle. For example, the antibody treatment period may consist of all the antibody treatment days within a treatment cycle. The antibody treatment days do not have to be consecutive days within a cycle. The antibody treatment period may be the same period as the treatment cycle, but if the treatment cycle also includes SBRT, then the antibody treatment period is preferably fewer days than a treatment cycle.

[0115] Administration of the Combination Therapy

[0116] In one embodiment, the anti-GD2 antibody or fragment may be prepared e.g. for parenteral administration e.g., subcutaneous, intramuscular, intravenous, intradermal, intra-articular or peri-articular administration, particularly in the form of liquid solutions or suspensions; or for inhalation to the lungs e.g. pulmonary administration, particularly in the form of solutions, suspensions including nanosuspensions for nebulisation, or suspension or solution pressurised or non-pressurised aerosols.

[0117] The anti-GD2 antibody or fragment may be administered by inhalation. An advantage of inhaled medications is their direct delivery to the area of rich blood supply in comparison to many medications taken by oral route. Thus, the absorption is very rapid as the alveoli have an enormous surface area and rich blood supply and first pass metabolism is bypassed.

[0118] The anti-GD2 antibody or fragment may conveniently be administered in unit dosage form and may be prepared by any of the methods well-known in the pharmaceutical art. The anti-GD2 antibody or fragment may also conveniently be administered in multiple unit dosage form.

[0119] The present invention also provides an inhalation device containing the anti-GD2 antibody or fragment of the present invention. Typically said device is a metered dose inhaler (MDI), which contains a pharmaceutically acceptable chemical propellant to push the medication out of the inhaler.

[0120] In a preferred embodiment of any of the aspects of the invention, the administration to the patient of the anti-GD2 antibody or fragment is by intravenous administration, optionally by infusion, optionally by an infusion pump.

[0121] Preferably, the anti-GD2 antibody is administered by using a mini-pump. Suitably, the mini-pump is a commercially available mini-pump. The present disclosure provides pharmaceutical compositions comprising anti-GD2 antibodies or fragments thereof. Such compositions may comprise a prophylactically or therapeutically effective amount of the active drug (anti-GD2 antibodies or fragments thereof), and a pharmaceutically acceptable carrier. In a specific embodiment, the term "pharmaceutically acceptable" means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans. The term "carrier" refers to a diluent, excipient, or vehicle with which the therapeutic is administered. Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Water is a particular carrier when the pharmaceutical composition is administered intravenously. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions. Other suitable pharmaceutical excipients include starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like.

[0122] The various compositions in the context of the therapies and administrations described herein, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents. These compositions can take the form of solutions, suspensions, emulsion, tablets, pills, capsules, powders, sustained-release formulations and the like. Oral formulations can include standard carriers such as pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, magnesium carbonate, etc. Examples of suitable pharmaceutical agents are described in "Remington's Pharmaceutical Sciences." Such compositions will contain a prophylactically or therapeutically effective amount of the agent, preferably in purified form, together with a suitable amount of carrier so as to provide the form for proper administration to the patient. The formulation should suit the mode of administration, which can be oral, intravenous, intraarterial, intrabuccal, intranasal, nebulized, bronchial inhalation, intra-rectal, vaginal, topical or delivered by mechanical ventilation.

[0123] Pharmaceutically acceptable salts include the acid salts and those which are formed with inorganic acids such as, for example, hydrochloric or phosphoric acids, or such organic acids as acetic, oxalic, tartaric, mandelic, and the like. Salts formed with the free carboxyl groups may also be derived from inorganic bases such as, for example, sodium, potassium, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropylamine, trimethylamine, 2-ethylamino ethanol, histidine, procaine, and the like.

[0124] Generally, the ingredients of compositions of the disclosure are supplied either separately or mixed together in unit dosage form, for example, as a dry lyophilized powder or water-free concentrate in a hermetically sealed container such as an ampoule or sachette indicating the quantity of active agent. Where the composition is to be administered by infusion, it can be dispensed with an infusion bottle containing sterile pharmaceutical grade water or saline. Where the composition is administered by injection, an ampoule of sterile water for injection or saline can be provided so that the ingredients may be mixed prior to administration.

[0125] The anti-GD2 antibody or fragment, and / or the SBRT may be administered according to a dosage regimen.

[0126] An antibody fragment is to be administered at an equivalent fragment dose having an equivalent antagonistic effect on GD2 to the whole antibody from which the fragment is derived. The equivalent fragment dose may be calculated according to the fragment molecular weight compared to the molecular weight of the whole antibody, also referred to as parent antibody. For example, if a given antibody has a molecular weight of 150 kD, and a Fab fragment has a molecular weight of 50 kD, then a fragment dose that is one third of the antibody dose should provide an equivalent antagonistic effect on GD2. The equivalent antagonistic effect on GD2 may also be determined according to the amount of GD2 that the fragment can specifically bind to, compared to the amount of GD2 that the parent antibody can specifically bind to. These amounts may be determined by various assays, including ELISA.

[0127] The anti-GD2 antibody administration is preferably initiated within 1 week of completion of administration of the SBRT at the one or more metastatic sites. For example, the anti-GD2 antibody administration may be initiated on day 7, 6, 5, 4, 3, 2, or 1 of, or on the same day as, the completion of the administration of the SBRT at the one or more metastatic sites. Optionally, the anti-GD2 antibody administration may be initiated within 3 days of completion of administration of the SBRT at the one or more metastatic sites, preferably wherein the anti-GD2 antibody is dinutuximab beta. By "cumulative dose", the inventor(s) mean the total dose that is administered during the overall treatment time. The units of dose are expressed in mg / m2, where the area (in m2) refers to the patient's body surface area (BSA). For example, if a patient has a body surface area of 0.7 m2, then a cumulative dose of 3000 mg / m2would be 2100 mg.

[0128] The anti-GD2 antibody (such as dinutuximab beta) may be administered at a cumulative dose of up to 3000 mg / m2, such as at a cumulative dose of at least 100 mg / m2, such as from 100 to 200 mg / m2, from 200 to 300 mg / m2, from 300 to 400 mg / m2, from 400 to 500 mg / m2, from 500 to 600 mg / m2, from 600 to 700 mg / m2, from 700 to 800 mg / m2, from 800 to 900 mg / m2, from 900 to 1000 mg / m2, from 1000 to 1100 mg / m2, from 1100 to 1200 mg / m2, from 1200 to 1300 mg / m2, from 1300 to

[0129] 1400 mg / m2, from 1400 to 1500 mg / m2, from 1500 to 1600 mg / m2, from 1600 to

[0130] 1700 mg / m2, from 1700 to 1800 mg / m2, from 1800 to 1900 mg / m2, from 1900 to

[0131] 2000 mg / m2, from 2000 to 2100 mg / m2, from 2100 to 2200 mg / m2, from 2200 to

[0132] 2300 mg / m2, from 2300 to 2400 mg / m2, from 2400 to 2500 mg / m2, from 2500 to

[0133] 2600 mg / m2, from 2600 to 2700 mg / m2, from 2700 to 2800 mg / m2, from 2800 to

[0134] 2900 mg / m2, or from 2900 to 3000 mg / m2. Preferably the cumulative dose is up to

[0135] 850 mg / m2, up to 950 mg / m2, up to 1050 mg / m2, up to 1250 mg / m2, up to 1350 mg / m2, up to 1450 mg / m2, up to 1550 mg / m2, or up to 2050 mg / m2.

[0136] The anti-GD2 antibody (such as dinutuximab beta) may be administered to the patient in a dose of up to 200 mg / m2per cycle during one or more cycles, For example, the anti-GD2 antibody (such as dinutuximab beta) may be administered to the patient in a dose of up to 200 mg / m2per cycle during 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 cycles. For example, the anti-GD2 antibody (such as dinutuximab beta) may be administered to the patient in a dose of up to 150 mg / m2per cycle during 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 cycles. For example, the anti-GD2 antibody (such as dinutuximab beta) may be administered to the patient in a dose of up to 100 mg / m2per cycle during 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 cycles. Each cycle may be the same number of days as one or more of the other cycles in the treatment. For example, all the cycles may last 35 days.

[0137] The one or more cycles during which the anti-GD2 antibody is administered are preferably of 35 ± 3 days per cycle, such as 32, 33, 34, 35, 36, 37, 38 days, more preferably of 35 days per cycle. The cycles may all be from 32 to 38 days per cycle. The anti-GD2 antibody may be administered to the patient in a dose per cycle that is equal for all cycles during which the anti-GD2 antibody is administered. For example, the anti-GD2 antibody may be administered to the patient in a dose per cycle that is at least 10 mg / m2per cycle, such as from 10 to 30 mg / m2per cycle, from 20 to 40 mg / m2per cycle, from 30 to 50 mg / m2per cycle, from 40 to 60 mg / m2per cycle, from 50 to 70 mg / m2per cycle, from 60 to 80 mg / m2per cycle, from 70 to 90 mg / m2per cycle, from 80 to 100 mg / m2per cycle, from 90 to 110 mg / m2per cycle, from 100 to 120 mg / m2per cycle, from 110 to 130 mg / m2per cycle, from 120 to 140 mg / m2per cycle, from 130 to 150 mg / m2per cycle, from 140 to 160 mg / m2per cycle, from 150 to 170 mg / m2per cycle, from 160 to 180 mg / m2per cycle, from 170 to 190 mgm2per cycle, from 180 to 200 mg / m2per cycle, or from 190 to 200 mg / m2per cycle.

[0138] Each dose administered in the same dosage regimen or cycle does not have to be of the same dosage amount. Further, the subject may be administered a different anti- GD2 antibody or fragment as part of the same dosing regime. For example, the first dose may comprise dinutuximab beta, and the second dose may comprise a different anti-GD2 antibody or fragment, such as one or more selected from dinutuximab or naxitamab. A third dose may comprise the same antibody or fragment as the first and / or second dose, or a different antibody or fragment as the first and / or second dose.

[0139] Alternatively, the same anti-GD2 antibody or fragment may be used throughout the treatment (e.g., for each dose). Preferably, each dose comprises or consists of dinutuximab beta. Preferably, the anti-GD2 antibody in each cycle is dinutuximab beta.

[0140] In particular, the anti-GD2 antibody, such as dinutuximab beta, may be administered continuously over the first 10 consecutive days of a cycle at the daily dose of 10 mg / m2, particularly for patients over 12 kg. It may alternatively be administered as 5 daily discontinuous infusions of 20 mg / m2, optionally each infusion is over 8 hours, Preferably the 5 daily discontinuous infusions are on the first 5 days of one or more (e.g. each) cycle. Infusion times and rate may be extended and / or lowered to increase tolerability.

[0141] Each dose of anti-GD2 antibody, such as dinutuximab beta, may calculated based on the body surface area (BSA) or body weight as follows:

[0142] • Patients >12 kg may be dosed based on the BSA, for example 10 mg / m2 / day • Patients < 12 kg may be dosed according to their body weight, for example 0.33 mg / kg / day

[0143] The anti-GD2 antibody may be administered to the patient in a dose per cycle that varies by up to 20 mg / m2between different cycles during which the anti-GD2 antibody is administered. For example, the anti-GD2 antibody may be administered to the patient in a dose per cycle that varies by, such as, up to 10 mg / m2between different cycles during which the anti-GD2 antibody is administered. In these embodiments, the same dose of anti-GD2 antibody may be administered for one or more cycles but at least one cycle comprises the administration of a different antibody dose.

[0144] Suitably, the anti-GD2 antibody, such as dinutuximab beta, may be administered to the patient in a dose per cycle of at least 10 mg / m2per cycle for all cycles, such as: from 10 to 30 mg / m2per cycle for one or more cycles and from 20 to 40 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 20 to 40 mg / m2per cycle for one or more cycles and from 30 to 50 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 20 to 40 mg / m2per cycle for one or more cycles and from 40 to 60 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 40 to 60 mg / m2per cycle for one or more cycles and from 60 to 80 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 60 to 80 mg / m2per cycle for one or more cycles and from 80 to 100 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 100 to 120 mg / m2per cycle for one or more cycles and from 120 to 140 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 120 to 140 mg / m2per cycle for one or more cycles and from 140 to 160 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 140 to 160 mg / m2per cycle for one or more cycles and from 160 to 180 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 160 to 180 mg / m2per cycle for one or more cycles and from 180 to 200 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered.

[0145] The anti-GD2 antibody may be administered to the patient in a dose per cycle of 20 mg / m2, 30 mg / m2, 40 mg / m2, 50 mg / m2, 60 mg / m2, 70 mg / m2, 80 mg / m2, 90 mg / m2, 100 mg / m2, 110 mg / m2, 120 mg / m2, 130 mg / m2, 140 mg / m2, 150 mg / m2, 160 mg / m2, 170 mg / m2, 180 mg / m2, 190 mg / m2, or 200 mg / m2. As discussed above, the dose in each cycle does not need to be the same, or on the same antibody treatment days within each cycle. One or more cycles may comprise administration of the antibody at different doses.

[0146] The anti-GD2 antibody may be administered to the patient at a dose of at least 1 mg / m2 / day, such as from 1 to 2 mg / m2 / day, from 2 to 3 mg / m2 / day, from 3 to 4 mg / m2 / day, from 4 to 5 mg / m2 / day, from 5 to 6 mg / m2 / day, from 6 to 7 mg / m2 / day, from 7 to 8 mg / m2 / day, from 8 to 9 mg / m2 / day, from 9 to 10 mg / m2 / day, or 10 mg / m2 / day. As discussed above, the dose in each cycle does not need to be the same, or on the same antibody treatment days within each cycle. One or more cycles may comprise administration of the antibody at different doses.

[0147] If the patient has a weight of greater than 12 kg, the anti-GD2 antibody is preferably administered to the patient at a dose of from 8 to 12 mg / m2 / day, preferably 10 mg / m2 / day. If the patient has a weight of from greater than 5 kg to 12 kg, the anti- GD2 antibody is preferably administered to the patient at a dose of from 0.25 to 0.5 mg / kg / day, more preferably 0.33 mg / kg / day. If the patient has a weight of 5 kg or less, the anti-GD2 antibody is preferably administered to the patient at a dose of from 0.15 to 0.3 mg / kg / day, more preferably 0.22 mg / kg / day. Suitably, patients with a body weight < 12 kg may be dosed according to their weight in kg instead of their body surface area (m2) according to the known formula of 30 kg= 1 m2.

[0148] The anti-GD2 antibody is administered to the patient in a daily dose of from 1 to 25 mg / m2, such as a daily dose of 1, 2, 3, 4, 5, 6, 7, 7.5, 8, 9, 10, 11, 12, 12.5, 13, 14, 15, 16, 17, 17.5, 18, 19, 20, 21, 22, 22.5, 23, 24 or 25 mg / m2. The daily dose may not be the same on every antibody treatment day of a cycle and / or of a treatment period. Preferably, the anti-GD2 antibody is administered to the patient in a daily dose of 7, 10, 15 or 20 mg / m2.

[0149] The anti-GD2 antibody, such as dinutuximab beta, may be administered to the patient as a continuous intravenous infusion over 24 hours per day, optionally wherein the continuous intravenous infusion of the anti-GD2 antibody is in any of the daily doses listed above, preferably 10 mg / m2. The continuous intravenous infusion over 24 hours per day may be administered by a mini-pump, for example a commercially available mini-pump.

[0150] The anti-GD2 antibody may be administered to the patient on consecutive days of a cycle until all of the dose per cycle of the anti-GD2 antibody has been administered. For example, if there are 5 daily doses of the anti-GD2 antibody in a cycle, the 5 daily doses may be given on 5 consecutive days. The consecutive days may be at the beginning, middle or end of a cycle. For example, if a cycle has 10 days, and there are 5 daily doses, the treatment may be initiated on day 1, 2, 3, 4, 5 or 6. For example, if a cycle has 7 days, and there are 5 daily doses, the treatment may be initiated on day 1, 2, or 3.

[0151] Suitably, the anti-GD2 antibody may be administered to the patient as a number of daily discontinuous infusions of from 10 to 30 mg / m2, preferably 20 mg / m2. Each infusion may be 8 or more hours, preferably over 8, 9, 10, 11, 12 hours. The number of daily continuous infusions may be from 1 to 10 infusions per cycle. The infusions may be on the first days of each cycle. For example, if there are 5 daily discontinuous infusions, they may be on the first 5 days of each cycle. Infusion times and rate may be extended or lowered as needed between infusions and / or treatment cycles to increase tolerability.

[0152] Preferably, the anti-GD2 antibody may be administered to the patient as 5 daily discontinuous infusions of 20 mg / m2, each over 8 hours, on the first 5 days of each cycle.

[0153] The SBR.T treatment may be completed in an outpatient setting, and the administration of dinutuximab beta may occur in the inpatient setting.

[0154] The anti-GD2 antibody may preferably be administered without concomitant administration of IL-2. Studies have shown that the addition of (subcutaneous) IL-2 to dinutuximab beta (for example, 8-hr / short-term infusion) did not significantly improve survival. In an intention-to-treat analysis, there was no differences in 3-year event-free survival (EFS) between patients treated without versus with subcutaneous IL-2 and the cumulative incidence of relapse or progression at 3 years did not differ between both groups. There was also no difference in 5-year OS between patients treated without versus with IL-2. Further, the addition of subcutaneous IL-2 to dinutuximab beta resulted in greater toxicity than dinutuximab beta alone. Patients assigned to receive IL-2 had higher rates of fever, pain, allergic reaction, capillary leak syndrome, hematologic toxicity, neurotoxicity, and gastrointestinal toxicity.37

[0155] Further studies have shown that 2-year EFS did not differ between those randomized to dinutuximab beta LTI alone or with (dose-reduced) subcutaneous IL-2 (EFS: 64%±4% vs 63%±5%, p = 0.844 and OS: 83%±3% vs 74%±4%, p = 0.337). Patients who received dinutuximab beta LTI alone compared to with subcutaneous IL- 2 had lower rates of Grade 3 and 4 toxicities of fever (14% vs 31%, p < 0.001) and pain (7%vsl8%, p = 0.005). There were not significant differences in allergic reaction, capillary leak, elevated transaminases, and neurologic toxicities.35

[0156] Additional data from patients with relapsed or refractory neuroblastoma demonstrated that the combination of dinutuximab LTI and subcutaneous IL-2 resulted in the induction of T regulatory cells (Tregs). Treg levels were inversely correlated with IFN- y serum concentrations, and thus potentially inhibiting NK cell activity. Patients with low Treg levels had higher progression free survival compared to those with high Treg levels.40Therefore, advantageously, the anti-GD2 antibodies of the methods of the present invention may be administered without concomitant administration of IL-2.

[0157] Neuropathic pain, allergic reactions, and fever may be seen in patients who are administered an anti-GD2 antibody, such as dinutuximab beta. Institutional guidelines for supportive care for administration of an anti-GD2 antibody, such as dinutuximab beta, may be followed. For instance, a pain management therapy, such as an analgesic, may be administered in combination with the anti-GD2 antibody.

[0158] The administration of the anti-GD2 antibody may be accompanied by the administration of an analgesic, preferably wherein the analgesic comprises an opiate such as morphine. For example, the administration of the anti-GD2 antibody, such as dinutuximab beta, may be accompanied by the administration of morphine and / or one or more other analgesics. By "accompanied by" the inventor(s) mean that the treatment of the invention comprises administration to the patient of morphine and / or one or more other analgesics in combination with the rest of the treatment as described herein (SBRT and anti-GD2 antibody or fragment thereof). For example, the analgesic may comprise or consist of morphine. The morphine may be administered only for some but not all days on which the anti-GD2 antibody is administered. Alternatively, the morphine may be administered on or for all days on which the anti-GD2 antibody is administered.

[0159] The analgesic (such as morphine) dose administered during one or more hours or days of the administration of the anti-GD2 antibody and / or of all analgesic treatment hours or days may be lower than 50 mcg / kg / h, or lower than 30 mcg / kg / h.

[0160] To reduce opiate requirements during the anti-GD2 antibody (such as dinutuximab beta) therapy, gabapentin dosing may be used. To optimize the effect of gabapentin, it may be initiated 1 week prior to expected start of antibody dosing so that gabapentin can be increased to full dose by the start of the anti-GD2 antibody administration. Dosing typically will follow institutional standards.

[0161] An exemplary dosing of gabapentin in the week before the commencement of cycle 1 of antibody treatment may be as follows:

[0162] • First day of gabapentin: 5 mg / kg / dose (max 300 mg / dose) at bedtime

[0163] • Second day of gabapentin: 5 mg / kg / dose (max 300 mg / dose) BID

[0164] • Third day of gabapentin: 5 mg / kg / dose (max 300 mg / dose) TID (patients are preferably at this dose by the time of admission for Cycle 1 of the antibody, such as dinutuximab beta)

[0165] Suitably, gabapentin doses may be increased further if necessary.

[0166] Use of a patient-controlled analgesia device (PCA) or continuous opioid infusion during the anti-GD2 antibody, such as dinutuximab beta, infusion is preferred. Morphine is the most preferred analgesic / opioid for this use. Hydromorphone or fentanyl may be used in addition to, or alternatively instead of, morphine. For example, hydromorphone or fentanyl may be used in patients with known indications for use of hydromorphone or fentanyl.

[0167] A preferred starting dose of analgesics may comprise one or more of the following points:

[0168] • Morphine may be administered at 0.1 mg / kg / dose, preferably 20 minutes prior to initiation of the first antibody, such as dinutuximab beta, infusion. A continuous morphine infusion of 0.02 mg / kg / hr may also be initiated optionally with bolus doses of 0.01 mg / kg / dose ql5 minutes prn for pain.

[0169] • If a hydromorphone PCA is used, it is preferred to initiate the hydromorphone pre-infusion at a dose of 0.02 mg / kg / dose, preferably 20 minutes prior to starting the infusion of the first antibody, such as dinutuximab beta, infusion. A continuous hydromorphone infusion of 0.004 mg / kg / hr (maximum initial rate is preferred to be 0.2 mg / hour for opioid naive patients) may also be initiated optionally with bolus doses of 0.002 mg / kg / dose ql5 minutes prn for pain.

[0170] • If fentanyl PCA is used, it is preferred to initiate administration of fentanyl 1 mcg / kg, preferably 10 minutes prior to starting the first infusion of the antibody (such as dinutuximab beta). A continuous fentanyl infusion of 0.5 micrograms / kg / hr may also be initiated optionally with bolus doses of 0.25 micrograms / kg / dose qlO minutes prn pain. • For patients unable to use a PCA, a continuous basal infusion of morphine and / or alternative analgesic medication may be administered and, optionally, as- needed boluses of the same medication may be used.

[0171] Starting doses of the basal infusion and boluses are preferably based on one or more of patient weight, institutional standard practices, and doses required by individual patients for treatment of pain associated with previous interventions / treatments.

[0172] Doses may be titrated as needed in accordance with institutional guidelines.

[0173] The dose of one or more analgesics, optionally morphine and / or another analgesic, may be reduced, optionally continually reduced, from the starting dose in one or more subsequent doses of analgesic.

[0174] The dose of the one or more analgesics, optionally morphine, may be reduced within one or more of the overall treatment time, a treatment cycle, during the antibody treatment period within a treatment cycle, from one antibody treatment day to the next antibody treatment day within a treatment cycle, and / or from one treatment cycle to the next. When the dose of one or more analgesics is reduced from one antibody treatment day to the next antibody treatment day within a treatment cycle, the antibody treatment days do not have to be on consecutive days. The doses may be reduced and then stabilised at the reduced dose. For example, if there are 4 doses of analgesic, the second dose may be lower than the starting (first) dose, the third dose may be lower than or the same as the second dose, and the fourth dose may be lower than or the same as the third dose. Alternatively, if there are 4 doses of analgesic, the second dose may be the same as the starting (first) dose, and the third and / or fourth dose may be lower than the first and second dose.

[0175] Suitably, the morphine dose may be continuously reduced within a treatment cycle, during the antibody treatment period within a treatment cycle, and / or from one antibody treatment day to the next antibody treatment day within a treatment cycle.

[0176] By "continuously reduced" the inventor(s) mean that the dose is reduced in each subsequent dose. For example, if there are 4 doses of analgesic, the second dose will be lower than the starting (first) dose, the third dose will be lower than the second dose, and the fourth dose will be lower than the third dose. In certain embodiments, the therapeutic effect of the combination anti-GD2 antibody and SBR.T therapy may be defined as stable disease (i.e., no further increase in lesions, tumor tissue and / or size), partial response (i.e., reduction in lesions, tumor tissue and / or size), and / or complete response (i.e., complete remission of all lesions and tumor tissue). In some embodiments, the therapeutic effect of anti-GD2 antibody, such as dinutuximab beta, administration may be an increase in immune response to the tumor, as determined, for example, by an increase in immune system biomarkers (e.g., blood parameters, such as lymphocyte counts and / or NK cell numbers; and / or cytokines). In some embodiments, the therapeutic effect may be a reduction in tumor markers (e.g., catecholamines). In some embodiments, the therapeutic effect may be determined by methods such as metaiodobenzylguanidine scintigraphy (mIBG), magnetic resonance imaging (MRI), or X-ray computed tomography (CT), and / or bone marrow histology (assessed by aspirate or trephine biopsy).

[0177] The anti-GD2 antibody may be administered for a treatment period until one or more certain therapeutic effects have been reached. The anti-GD2 antibody may be administered for a treatment period until a certain therapeutic effect has been reached. The therapeutic effect may be (but is not limited to) one or more of the therapeutic effects listed above. The certain therapeutic effect which when achieved ends the anti- GD2 antibody administration, may be chosen based on a number of factors, such as characteristics of the patient, their disease type and progression, efficacy of previous and / or simultaneous treatments, management of symptoms, managing (reducing) side effects of the treatment and so on.

[0178] The anti-GD2 antibody may have a predetermined overall patient dose and the anti- GD2 antibody may be administered for a treatment period until the predetermined overall patient dose has been administered. By "predetermined overall patient dose" the inventor(s) mean that a dose of anti-GD2 antibody may be determined before or during the treatment period. For example, the predetermined dose may be a certain cumulative dose which is determined before the initial antibody dose is given. Alternatively, the predetermined dose may be a cumulative dose determined after the initial dose of the antibody, for example in the first half of a first treatment cycle, or a cumulative dose for the whole antibody treatment may be determined after a first treatment cycle. The predetermined dose may apply per cycle, or for the whole treatment period (i.e., across multiple cycles).

[0179] Suitably, in any of the aspects of the invention, the administration of the anti-GD2 antibody (for example, dinutuximab beta) improves one or more clinical parameters compared to the SBRT or anti-GD2 antibody administered in isolation. For example, the administration of the anti-GD2 antibody, such as dinutuximab beta, may improve one or more clinical parameters compared to the SBRT administered without the anti- GD2 antibody. International neuroblastoma response criteria have been previously described.1Suitable clinical parameters may be selected from overall response rate (ORR), complete response (CR) rate, partial response (PR) rate, primary tumour volume reduction, Curie score, event-free survival (EFS), and overall survival (OS), overall response during and after induction (primary tumor, metastases), and metastatic CR and PR rates. EFS and OS may be determined at 3 or 5 years. ORR includes CR, and PR. Clinical improvement may also be characterized by changes in immune parameters during SBRT for patients also treated with anti-GD2 antibody. Suitable immune parameters are Immunophenotype, complement-dependent cytotoxicity (CDC) and ADCC.

[0180] The response for different sites and the overall response may be further defined as described in Example 1 below.

[0181] A second aspect of the invention provides a anti-GD2 antibody for use in a method of treating metastasis in a GD2-positive cancer in a patient by administering anti-GD2 antibody to the patient in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites, preferably wherein the anti-GD2 antibody is dinutuximab beta. A third aspect of the invention provides a use of anti-GD2 antibody in the preparation of a medicament for treating metastasis in a GD2-positive cancer in a patient, wherein the medicament is for administration to the patient in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites, preferably wherein the anti-GD2 antibody is dinutuximab beta. A fourth aspect of the invention provides a use of anti-GD2 antibody for treating metastasis in a GD2-positive cancer in a patient in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites, preferably wherein the anti-GD2 antibody is dinutuximab beta. A fifth aspect of the invention provides a means for binding GD2 to treat metastasis of a GD2- positive cancer in a patient in need thereof, in combination with SBRT at one or more metastatic sites. The preferred and optional features of the first aspect of the invention are equally applicable to the second, third, fourth and fifth aspects, respectively.

[0182] DESCRIPTION OF THE FIGURES

[0183] Figure 1 shows a flow diagram of the schema of Example 1. Figure 2 shows gene expression analysis of irradiated tumors following SBRT and association with irradiated tumor response.

[0184] EXAMPLES

[0185] The invention will now be illustrated by the following non-limiting example.

[0186] Example 1: Phase 1 study of dinutuximab beta with stereotactic body radiotherapy (SBRT) for the treatment of metastasis in relapsed or refractory neuroblastoma in children, adolescents, and young adults.

[0187] 1.1. Study Synopsis

[0188] Description:

[0189] This single arm, open label, phase 1 study will examine the safety of SBRT combined with dinutuximab beta in patients with relapsed or refractory neuroblastoma. The study will determine safe doses of radiation based on anatomic site in conjunction with dinutuximab beta. Patients will be treated with SBRT (5 days). Two dose levels will be considered (level 1 and level -1). Dinutuximab beta (continuous intravenous infusion over 10 days at a daily dose of 10 mg / m2 / day every 5 weeks [or adjusted based on weight]) will be begin 3 days following SBRT for up to 12 cycles. Toxicities will be reported using CTCAEv5.0 with investigators using clinical judgment to determine attribution of toxicity to relevant organ systems. The inventor(s) hypothesize that SBRT combined with dinutuximab beta will be safe, and the treatment will have activity against neuroblastoma.

[0190] Pre-treatment and post-radiation tumor biopsy specimens (optional) along with mandatory blood collections, to assay for changes that may reflect a more favorable response to immunotherapy, will be collected. Additionally, stool and blood samples will be taken and the gut microbiome (16S sequencing) and blood-based biomarkers (cfDNA- 5hmc profiles) will be longitudinally measured and correlated with response and disease burden.

[0191] Objectives:

[0192] Primary Objective

[0193] • To determine the safety and define the toxicities of the combination of stereotactic body radiotherapy (SBRT) and anti-GD2 therapy with dinutuximab beta in patients with refractory or recurrent high-risk neuroblastoma.

[0194] Secondary Objectives • To determine the objective response rate (ORR) at 10 weeks and best overall response

[0195] • To evaluate time to progression of disease outside radiated fields and overall time to progression.

[0196] Exploratory Objectives:

[0197] • To explore the immunological effects of the combination of SBRT and anti-GD2 therapy with dinutuximab beta by assessing a defined T cell-inflamed gene expression signature and other molecular markers in tumor samples.

[0198] • To explore potential microbiome and epigenetic cell-free DNA biomarkers associated with response to treatment with combination of stereotactic body radiotherapy (SBRT) and dinutuximab beta.

[0199] Endpoints:

[0200] Primary Endpoints

[0201] • Dose limiting toxicity (DLT) during the first 10 weeks of treatment with SBRT + dinutuximab beta (early toxicity) in patients with relapsed or refractory neuroblastoma. The recommended SBRT dose for metastatic soft tissue and bone disease will be based on anatomic site and determined by DLT derived from clinical and laboratory observations from this period, according to the National Cancer Institute Common Terminology for Adverse Events Criteria (NCI CTCAE v5.0) that is related to.

[0202] Secondary Endpoints

[0203] • ORR at 10 weeks and best overall response will be determined by the 2017 International Neuroblastoma Response Criteria.1Objective response will be defined in two ways: 1) complete response (CR) + partial response (PR) and 2) CR + PR + minor response (MR).

[0204] • Time-to-progression of disease outside radiated fields is defined as time from the date of study enrollment to the first occurrence of objective disease progression regions outside radiated fields or date of death due to any cause, whichever occurs first. Time-to-overall progression is defined as time from the date of study enrollment to the first occurrence of objective disease progression at any site or date of death due to any cause, whichever occurs first.

[0205] Description of Study Intervention: Participants will undergo SBRT to 1-4 eligible metastatic lesions over the course of 1 week (Monday-Friday). Subsequently, treatment with dinutuximab beta (10 mg / m2 / day given continuously IV over 10 days; adjusted dosing for participants < 12 kg) every 5 weeks will be administered. Biopsies (optional), blood, and stool specimens will be collected prior to and after radiation. Additional blood and stool samples will be collected during the course of therapy.

[0206] Study Duration:

[0207] ~15-18 months (enrollment); ~30-36 months (duration of study)

[0208] Participant Duration:

[0209] Participants can receive up to 12 cycles of dinutuximab beta

[0210] 1.2. Schema

[0211] See Fig 1. for study outline

[0212] Tumor evaluations:

[0213] • Screening / baseline and after every 2 cycles of dinutuximab beta

[0214] Study treatment:

[0215] • Maximum of 12 cycles of dinutuximab beta

[0216] 1.3. Schedule of activities (SOA)

[0217] Treatment cycles: Treatment with dinutuximab beta must start within 1 week of final SBRT dose (ideally 3 days after final SBRT dose) and will constitute protocol "Day 1"; dinutuximab beta will be administered every 5 weeks (35 days) + / - 3 days. Participants can receive up to 12 cycles of dinutuximab beta on this study.

[0218] The full Schedule of activities (SOA) is described in Appendix 5.

[0219] 2. INTRODUCTION

[0220] 2.1. Study rationale

[0221] A phase 1 pediatric study designed to determine the safety of combining SBRT and the anti-GD2 antibody dinutuximab beta. Of particular note, this proposal is intended to incorporate SBRT as a direct therapeutic. This is in contrast with other proposals evaluating response at distant sites after isolated metastasis radiation. The inventor(s) are using ablative doses of radiation that have been shown to induce innate and adaptive immune pathways. The inventor(s) hypothesize these changes will enhance the activity of dinutuximab beta and the combination therapy will lead to tumor response. The inventor(s) will also conduct exploratory studies to investigate if changes in the tumor microenvironment, microbiome, and / or cfDNA epigenetic profiles before and after radiation therapy are associated with response to the combination therapy.

[0222] 2.2. Background

[0223] 2.2.1. Rationale for research design and population

[0224] 2.2.1.1. Neuroblastoma, anti-GD2 therapy, and the tumor microenvironment

[0225] Post-consolidation chimeric anti-GD2 monoclonal antibody (dinutuximab) with cytokines and isotretinoin has led to significant improvement in the survival of children with high-risk neuroblastoma.11Retrospective analysis also demonstrates improved survival with the addition of dinutuximab beta versus isotretinoin alone in the postconsolidation setting among patients with high-risk neuroblastoma.15Dinutuximab combined with irinotecan and temozolomide has also been shown to be effective in the setting of relapsed / refractory disease, with a response rate of ~ 40%.13-14While immunotherapy with anti-GD2 therapy has transformed the approach for treating high- risk neuroblastoma, a large subset of patients will not respond to anti-GD2 therapy. Pediatric cancers often demonstrate low mutational burden and are non-T cell-inflamed or "cold", with scarce tumor infiltrating lymphocytes amongst anti-inflammatory M2 tumor associated macrophages.15-17A potential approach to augment the activity of immunotherapy in this setting is by altering the tumor microenvironment through stereotactic body radiotherapy (SBRT).

[0226] 2.2.1.2. Pre-clinical data supporting higher fraction radiation in combination with immunotherapy agents

[0227] Higher fraction radiation (e.g. hypofractionated radiotherapy such as SBRT) has been associated with more robust adaptive immune responses in multiple tumor types; mechanisms of action include increased tumor antigen exposure, improved antigen presentation and T cell function, as well as modulation of immunosuppressive cell populations such as T regulatory cells and myeloid derived suppressor cells.18-20Implanted tumor models show that concomitant administration of radiation and anti- PD-L1 antibody results in significantly greater tumor reduction, as compared with radiation or anti-PD-Ll antibody treatment alone, in a murine system.21This effect was observed in both tumors within the radiation field as well as distant tumors, suggesting that the beneficial effects of radiation on immune response have systemic impact. Similar findings have been reported in patients receiving radiation and immunotherapy.22Beyond synergistic mechanisms of modulating the immune response, the direct anti-tumor effects of radiation may also be well suited as an adjunct to immunotherapy. Reports of SBRT with systemic therapies have suggested that time to progression is improved.23-24The efficacy of Immunotherapy may also be boosted by this approach where lower disease burden at the time of treatment initiation has been associated with higher response rate and one-year survival in advanced melanoma.25

[0228] 2.2.1.3. Clinical and correlative data: SBRT followed by Pembrolizumab in adults with advanced solid tumors

[0229] An investigator-initiated trial of adults evaluated multi-site SBRT (2-4 metastases) followed by pembrolizumab 200 mg IV every 3 weeks in advanced solid tumors (NCT02608385), demonstrated safety of the approach with no SBRT dose reductions. SBRT dose was based on anatomic site: 45 Gy in three fractions for the peripheral lung, liver, and abdominopelvic sites; 50 Gy in five fractions for central lung and mediastinal / cervical sites; 30 Gy in three fractions for osseous and spinal / paraspinal sites. Of 73 treated patients with SBRT followed by pembrolizumab for at least one cycle, six patients experienced dose-limiting toxicities (pneumonitis, n=3; colitis, n=2; hepatic failure, n = l), all CTCAEv4.0 Grade 3, with no radiation dose reductions. Of the 68 patients with follow-up imaging, the objective response rate was 13.2%. Using an aggregate diameter of non-irradiated Response Evaluation Criteria in Solid Tumors (RECIST) target metastases, out of field response rate was 13.2%; using a response defined by 30% reduction in any single, non-irradiated RECIST target metastasis, the response rate was 26.9%. Expression of interferon-y-associated genes in tumor specimens post SBRT correlated with non-irradiated tumor response.26

[0230] Additional correlative studies were completed as part of this trial.27An unsupervised analysis was performed on pre- and / or post-SBRT biopsies from 24 patients (19 pre- SBRT and 16 post-SBRT; 11 matched samples from the same tumor). RNA was extracted and analyzed using Affimetrex arrays. Bioinformatic analysis was performed adjusting for variation across different tumor histologies. Among patients with matched samples and across a variety of tumor histologies, SBRT induced pathways of innate and adaptive immunity, while reducing the expression of pathways involved in G2-M cell-cycle progression and DNA damage repair processes (Fig 1A). These findings are consistent with pre-clinical data as well as a study of SBRT for patients with oligometastatic prostate cancer.28-30

[0231] Post-SBRT biopsies (n = 16) demonstrated elevated expression of immune genes, including DNASE1 and CCR.10, and were associated with increased irradiated tumor response; while elevated expression of TGFBR3L and SIGLEC15 were strongly associated with decreased tumor response (Fig IB). DNASE1 has been shown to promote DNA degradation in the response to ionizing radiation, which may influence activation of cGAS-STING signaling in tumor cells.28Increased DNASE1 levels following SBRT were associated with increases in the expression of cytolytic T-cell genes (Fig 1C) and a ~2 fold improved local tumor response (Fig ID). Alternatively, TREX1 (DNase III) expression levels following SBRT were associated with decreased cytolytic gene expression (Fig 1C) and a ~21 / 2 fold reduced local tumor response.

[0232] 2.2.1.4. Trial hypothesis

[0233] • SBRT combined with dinutuximab-beta will be tolerable in children with recurrent or refractory neuroblastoma.

[0234] • SBRT combined with dinutuximab-beta will have antitumor activity in children with recurrent or refractory neuroblastoma.

[0235] 2.2.2. Dinutuximab beta

[0236] Dinutuximab beta is a chimeric monoclonal antibody produced in CHO cells targeting the disialoganglioside GD2 antigen highly expressed by neuroectodermal tumors such as neuroblastoma, melanoma cells, and several other tumors. "First generation" antibodies targeting the disialoganglioside GD2 antigen were entirely mouse products causing a quick immunological response. Dinutuximab beta belongs to the "second generation" anti-GD2 antibodies, chimeric products, and consists of approximately 30% mouse protein and 70% human protein. Dinutuximab beta mediates CDC against GD2-bearing cells. Furthermore, dinutuximab beta targets cytotoxic immune effector cells towards GD2-expressing tumor cells (ADCC).31

[0237] Physical, chemical, and pharmaceutical properties and formulation

[0238] Properties of Dinutuximab beta31:

[0239] 2.2.3. Stereotactic body radiotherapy and dinutuximab beta: dose rationale

[0240] 2.2.3.1. Stereotactic body radiotherapy (SBRT) dose rationale 2.2.3.1.1. SBRT doses in clinical trials conducted in adults

[0241] The doses of radiation that will be administered by anatomic site in this study are, in part, based on prior experience and clinical trials of SBRT, including NCT02206334- NRG-BR001, a phase 1 trial of SBRT to multiple metastatic sites in adults with breast cancer, non-small cell lung cancer, and prostate cancer and NCT02608385-Merck investigator-initiated phase 1 trial of SBRT + pembrolizumab in adults with advanced solid tumors (University of Chicago), and NCT03431948- Bristol Myer-Squibb investigator-initiated phase 1 trial of SBRT + nivolumab + urelumab or cabiralizumab in in adults with advanced solid tumors (University of Chicago).25'32-35This has been further adapted for pediatrics (As described in section 2.2.3.1.2 SBRT dosing in this pediatric trial). The NRG Oncology BR001 (nrgoncology.org / Clinical-Trials / NRG-BR001) trial assessed the toxicity and tolerability of treating 3-4 metastases or 2 metastases within 5 cm simultaneously based on known safety, efficacy, and expert consensus agreement on data targeting 1-4 metastases. Based on all available data, a consensus of Radiation Therapy Oncology Groups (RTOG) experts selected the SBRT doses to be used in this study. Doses were selected based on high rates of treated metastasis control, and low reported rates of normal tissue toxicity from prior phase 1 and phase 2 studies. The expert consensus panel also tabulated all known normal tissue tolerances to ensure low risk to surrounding normal tissues, which will be used for the planning SBRT dose constraints. The starting dose for SBRT doses on this study was 50Gy in 5 fractions to the central lung and mediastinal / cervical lymph nodes, 45Gy in 3 fractions to the peripheral lung, abdominal / pelvic, and liver metastases, and 30Gy in 3 fractions to bone / osseous and spinal / paraspinal metastases. There were no pre-specified doselimiting toxicities (DLTs) reported for bone / osseous, spinal / paraspinal, peripheral lung, abdominal / pelvic , central lung, liver, and / or mediastinal / cervical lymph node locations.32-34

[0242] A Merck investigator-initiated trial of SBRT + pembrolizumab (NCT02608385) in adults with advanced solid tumors at the University of Chicago derived SBRT doses to the same anatomic sites from the NRG Oncology BR001 experience. This study investigated multi-site SBRT (2-4 metastases) followed by pembrolizumab 200 mg IV every 3 weeks in advanced solid tumors and demonstrated safety of the approach with no SBRT dose reductions. A subset of patients had at least one metastasis measuring >65 mL that was partially treated with SBRT, with the hypothesis that this partial irradiation would lead to cytoreduction while inducing effector T-cell trafficking throughout the remaining unirradiated portion of the lesion to enhance the local effects of PD-1 blockade. In analysis comparing patients with at least one tumor partially irradiated with patients whose tumors were completely irradiated, there was no statistically significant difference in control at 3 months (88% for the partially irradiated patients v 95% for the completely irradiated group; p = .108).25

[0243] Building on the experience of NRG Oncology BR001 and the investigator-initiated trial of SBRT + pembrolizumab, an investigator-initiated phase 1 trial of SBRT + nivolumab + urelumab or cabiralizumab in patients with advanced solid tumors was conducted at the University of Chicago. SBRT was delivered to 1-4 metastases with nivolumab + urelumab or nivolumab + cabiralizumab given concurrently and following SBRT. Based on DLT evaluation, no prespecified SBRT dose de-escalation was recommended, and the initial SBRT doses for each anatomic site were deemed safe in this trial.35

[0244] 2.2.3. 1.2. SBRT dosing in this pediatric trial The pediatric dose of SBRT that will be investigated in this trial are based on prior experience and clinical trials of SBRT in adults as detailed in the above section (NRG- BR00132-34; NCT02608385-investigator-initiated trial of SBRT + pembrolizumab in adults with advanced solid tumors25; NCT03431948-investigator-initiated phase 1 trial of SBRT + nivolumab + urelumab or cabiralizumab35), clinical trials of SBRT in the pediatric population (such as ARST1431 [NCT02567435]), and current protocols for neuroblastoma (e.g. ANBL1531 [NCT04385277]). Radiation planning has been adapted for pediatrics and tumor histology.

[0245] Radiotherapy will be administered to one or more of the following sites categorized as: 1) lung, 2) mediastinal / thoracic (axillary or cervical) lymph node, 3) liver, 4) spinal / paraspinal / osseous, or 5) abdominal-pelvic metastases (e.g. lymph node). Only two dose levels at each site will be considered (level 1 and level -1, Table 3). Radiotherapy will be administered in 5 Fractions. In adapting this trial for the pediatric population, the doses to spinal / paraspinal / osseous sites remain consistent with hypofractionated radiotherapy but not extreme hypofractionation (i.e. SBRT). For the purposes of this protocol, the term SBRT will be used to describe the study intervention.

[0246] 2.2.3.2. Dinutuximab beta: dose rationale

[0247] 2.2.3.2.1. Dinutuximab beta dosing

[0248] The planned dose of dinutuximab beta for this pediatric study is a fixed dose of 10 mg / m2 / day given continuously over 10 days every 5 weeks. Children with a body weight < 12 kg will be dosed according to their weight in kg instead of their body surface area (m2) according to the known formula of 30 kg= 1 m2. Each dose is calculated based on the body surface area (BSA) or body weight as follows31:

[0249] • Patients >12 kg are dosed based on the BSA: 10 mg / m2 / day

[0250] • Patients < 12 kg are dosed according to their body weight: 0.33 mg / kg / day

[0251] 2.2.3.2.2. Rationale for long-term infusion

[0252] The continuous dosing administration schedule (i.e. long-term infusion) has been investigated as part of the following studies:

[0253] • APN311-303 (patients relapsed / refractory neuroblastoma; compassionate use)

[0254] • APN311-102 (patients with relapsed / refractory neuroblastoma; phase 1)

[0255] • APN311-202 (patients with relapsed / refractory neuroblastoma; phase 1 / 2)

[0256] • APN311-304 (patients with relapsed / refractory neuroblastoma; phase 2) • APN311-302-R4 (one period of the ongoing HRNBL-l / SIOPEN frontline study for high-risk neuroblastoma [R4 randomization; phase 2])35

[0257] As part of the frontline trial HR-NBL-1 conducted by International Society of Pediatric Oncology Europe Neuroblastoma (SIOPEN), patients were randomized to dinutuximab beta alone versus with subcutaneous interleukin 2 (IL-2) following myeloablative therapy and autologous stem cell rescue (R2 randomization). Dinutuximab beta was given on a schedule of five daily infusions of 20 mg / m2administered over 8 hours (total dose: 100 mg / m2).37In the interim, emerging data from APN311-202 suggested that the administration of dinutuximab beta as a long-term infusion (LTI, total antibody dose of 100 mg / m2over 10 days as a continuous infusion) was associated with less toxicity than the short-term infusion. Further, the combination of subcutaneous IL-2 with the long-term infusion appeared to be associated with less toxicity than when combined with the short-term infusion.38Given this, SIOPEN conducted a clinical trial (R4 randomization) comparing the outcome of patients with high-risk neuroblastoma receiving Post-Consolidation dinutuximab beta LTI alone versus with subcutaneous IL- 2. For those assigned to the IL-2-containing arm, a reduced dose of subcutaneous IL- 2 (3 million IU / m2 / day) was administered. Other studies have also demonstrated the favorable toxicity profile of the dinutuximab beta long-term infusion.39

[0258] 2.2.3.2.3. Rationale for eliminating IL-2 from the treatment regimen

[0259] In the Post-Consolidation R2 randomization portion of the HR-NBL-1 trial conducted by SIOPEN, the addition of the subcutaneous IL-2 to dinutuximab beta (8-hr / short-term infusion) did not significantly improve survival. In an intention-to-treat analysis, there was no differences in 3-year event-free survival (EFS) between patients treated without versus with subcutaneous IL-2 (56% [95% CI 49-63] versus 60% [95% CI 53-66], p=0.76), and the cumulative incidence of relapse or progression at 3 years did not differ between both groups. There was also no difference in 5-year OS between patients treated without versus with IL-2 (63% [95%CI 55-69] versus 62% [95%CI 55-69]; p=0.968). Further, the addition of subcutaneous IL-2 to dinutuximab beta resulted in greater toxicity than dinutuximab beta alone. Patients assigned to receive IL-2 had higher rates of fever, pain, allergic reaction, capillary leak syndrome, hematologic toxicity, neurotoxicity, and gastrointestinal toxicity. Only 62% of patients randomized to the subcutaneous IL-2 + dinutuximab beta arm received the planned therapy, while 87% of patients assigned to dinutuximab beta alone received the planned therapy.37

[0260] During the subsequent R4 randomization of HR-NBL-1, 2-year EFS did not differ between those randomized to dinutuximab beta LTI alone or with (dose-reduced) subcutaneous IL-2 (EFS: 64%±4% vs 63%±5%, p = 0.844 and OS: 83%±3% vs 74%±4%, p = 0.337). Patients who received dinutuximab beta LTI alone compared to with subcutaneous IL-2 had lower rates of Grade 3 and 4 toxicities of fever (14% vs 31%, p < 0.001) and pain (7%vsl8%, p = 0.005). There were not significant differences in allergic reaction, capillary leak, elevated transaminases, and neurologic toxicities. Given these results, SIOPEN has elected to eliminate IL-2 from PostConsolidation therapy.35

[0261] Additional data from a single center study conducted in patients with relapsed or refractory neuroblastoma (APN311-303) demonstrated that the combination of dinutuximab LTI and subcutaneous IL-2 resulted in the induction of T regulatory cells (Tregs). Treg levels were inversely correlated with IFN-y serum concentrations, and thus potentially inhibiting NK cell activity. Patients with low Treg levels had higher progression free survival compared to those with high Treg levels.40This data further supports the elimination of IL-2 from this regimen.

[0262] 2.2.4. Rationale for correlative biology studies

[0263] The T cell-inflamed tumor microenvironment may be a potential predictive biomarker for response to multiple immunotherapies including therapeutic vaccines, anti-CTLA-4, and anti-PD-l / PD-Ll antibodies41-47. The inventors' analysis of the tumor microenvironment in patients with melanoma suggests that approximately 35-50% of cases show evidence of spontaneous priming of anti-tumor T cells leading to migration of CD8+ effector T cells into tumor sites. This phenotype has been designated the T cell-inflamed tumor microenvironment and is characterized by the expression of T cell markers, chemokines for T cell recruitment, and transcripts indicative of type I IFN signaling42-43-45.

[0264] In addition to response prediction, this gene signature is also potentially useful in identifying those that will not respond. Patients harboring non-inflamed tumors therefore require treatment strategies which may modulate the immune response to facilitate the influx of tumor infiltrating lymphocytes (TIL) and conversion from a noninflamed to an inflamed tumor. Several tumor localized treatments have been suggested in preclinical models to facilitate such a shift, notably including radiation21. In preclinical studies, the addition of radiation to PD-L1 blockade has been shown to improve tumor control of implanted breast and colorectal carcinomas in mice with upregulation of PD-L1 after radiation treatment48. Administration of anti-PD-Ll enhanced the efficacy of radiation through a cytotoxic T cell-dependent mechanism with additional effects of immunosuppressive cell populations such as tumor-infiltrating myeloid-derived suppressor cells (MDSCs). Radiotherapy additionally has the potential to overcome other mechanisms of tumor immune escape such as the release of tumorspecific antigens, enhanced expression of Class I MHC in the tumor and the release of HMGB-1 (TLR4 agonist)49.

[0265] Using the T cell inflammation signature established by the inventors' colleagues, the inventor(s) analyzed publicly available expression data and categorized clinically annotated high-risk neuroblastoma diagnostic tumors as T cell inflamed, T cell-non- inflamed, or intermediate. Patients with T cell-inflamed high-risk tumors showed improved overall survival compared to those with non-T cell-inflamed tumors (p<0.05); independent of MYCN amplification status in both the discovery and validation cohorts. Higher neoantigen load was also associated with better event-free and overall survival (p<0.005) and was independent of the T cell-inflamed signature.50As the relationship between the T cell-inflamed gene expression signature, and / or neoantigen load, and response to anti-GD2 monoclonal antibodies is unknown, the inventor(s) will begin to evaluate this as part of this trial.

[0266] Gut microbiome and immune profiling (immunophenotypinq and cytokine analysis)

[0267] Beyond the tumor microenvironment, aspects of the host (patient) and commensal environment may also have an essential impact on immunity in response to both radiation and immunotherapies. Host factors of interest regarding the immune response include circulating immune profiles. Further, growing literature supports a role for commensal microbiota in the immune response to infection and cancer; including the development of acute versus chronic immune responses and regulatory mechanisms to prevent collateral tissue damage.51The inventors' colleagues, including co-investigators and others, have proposed that manipulation of the microbiome has the potential ability to modulate the anti-tumor immune response and promote the development of an inflamed tumor microenvironment.52’58As part of this study, the inventor(s) will longitudinally monitor peripheral blood immune profiles (using immunophenotyping and cytokine panels) and the gut microbiome to assess changes over the course of therapy as well as their correlation with response.

[0268] Liquid biopsy: whole genome 5-hmC biomarker signatures measured in circulating cell- free DNA

[0269] The paucity of genomic mutations in neuroblastoma emphasizes the key regulatory roles of the epigenome as drivers of oncogenic growth. Recent advances in epigenomic profiling offer new opportunities to characterize epigenetic modifications as novel markers of prognosis that could prove to be practice changing for treating children with neuroblastoma. Elevated 5-hydroxymethylcytosine (5-hmC) deposition across the body of a gene is known to facilitate active transcription, and the inventors' group previously evaluated whole genome 5-hmC marks in primary neuroblastoma tumors using the highly sensitive nano-hmC-Seal methodology developed at the University of Chicago.59These studies demonstrated that 5-hmC profiles differ in clinically aggressive neuroblastoma tumors and those with more benign clinical behavior. While these studies are promising, it is well recognized that tumor-derived biomarkers have significant limitations as a clinical test. Based on the ease of collection, peripheral blood samples are ideal for assaying biomarkers to monitor response and / or resistance to different therapies. In a retrospective analysis, whole genome 5-hmC biomarker signatures measured in circulating cell-free DNA (cfDNA) isolated from blood samples collected from neuroblastoma patients at diagnosis, during treatment, off therapy, and relapse have shown to be promising markers for metastatic disease and treatment response.50This epigenomic biomarker is being prospectively analyzed in serial blood samples collected on patients enrolled on the COG ANBL1531 high-risk neuroblastoma study. The inventor(s) will serially follow this marker in patients enrolled on this trial and correlate 5-hmC profiles with disease burden and response.

[0270] 2.3. Risk / Benefit Assessment

[0271] Radiotherapy and anti-GD2 therapy are established treatments for neuroblastoma. There is growing clinical experience of using multi-site SBRT alone or in combination with immunotherapy as described in 2.2.3.1 (Stereotactic Body Radiotherapy: Dose Rationale). The combination has been well tolerated and with acceptable toxicity in adult studies.25-35This study will investigate the sequential combination of SBRT and dinutuximab beta in children, adolescent, and young adult patients with relaped or refractory neuroblastoma, with the primary objective of determining the recommended SBRT dose in this combination and toxicities will be closely monitored.

[0272] 3. STUDY OBJECTIVES AND ENDPOINTS

[0273] 3.1. Primary objectives and endpoints

[0274] Objective:

[0275] To determine the safety of the combination of stereotactic body radiotherapy (SBRT) and anti-GD2 therapy with dinutuximab beta in patients with refractory or recurrent high-risk neuroblastoma.

[0276] Endpoint:

[0277] The primary endpoint is DLT during the first 10 weeks (early toxicity) in patients with relapsed or refractory neuroblastoma. The recommended SBRT dose for each metastatic location will be determined from DLT derived from clinical and laboratory observations from this period according to the National Cancer Institute Common Terminology for Adverse Events Criteria (NCI CTCAE v5.0) that is related to SBRT + dinutuximab beta.

[0278] Justification:

[0279] Different organ systems have been shown in clinical trials to tolerate varying doses of radiation.51Similarly, in the development of adult trials, it was hypothesized that toxicity may vary by organ system and dose of radiation when given with anti-PD-1 therapy. This combination has been well tolerated with acceptable toxicity in adult trials conducted at the inventors' institution with no SBRT dose reductions.25'35Based on this clinical data, the inventor(s) propose a pediatric phase 1 study of multi-site SBRT with dinutuximab beta to assess toxicity by organ system and define doses for combination approaches in the future.

[0280] 3.2. Secondary objectives and endpoints

[0281] Objectives:

[0282] • To determine the objective response rate (ORR) at 10 weeks and best overall response.

[0283] • To evaluate time to progression of disease outside radiated fields and overall time to progression.

[0284] Endpoint:

[0285] • ORR at 10 weeks and best overall response is defined using the 2017 International Neuroblastoma Response Criteria.1 Objective response will be defined in two ways: 1) complete response (CR) + partial response (PR) and 2) CR + PR + minor response (MR).

[0286] • Time-to-progression of disease outside radiated fields is defined as time from the date of study enrollment to the first occurrence of objective disease progression regions outside radiated fields or date of death due to any cause, whichever occurs first. Time-to-overall progression is defined similarly for time to first occurrence of objective disease progression at any site or date of death, whichever occurs first.

[0287] Justification:

[0288] • ORR will be determined based on neuroblastoma-specific response criteria.

[0289] • Progression free survival is being captured as the patient population includes patients with relapsed or refractory disease.

[0290] 3.3. Tertiary / exploratory objectives and endpoints Objectives:

[0291] • To evaluate changes in the immune effector cells and tumor microenvironment induced by the combination of radiation and dinutuximab beta.

[0292] • To explore potential microbiome and epigenetic cell-free DNA biomarkers associated with response to treatment with combination of stereotactic body radiotherapy (SBRT) and dinutuximab beta.

[0293] Endpoints:

[0294] • Longitudinal immunophenotyping and measurement of cytokines (e.g.IFN-y) in peripheral blood pre-post SBRT as well as change in expression of IFN-y associated genes in tumor specimens pre-post SBRT in those who undergo research biopsies (biopsies optional).

[0295] • Correlate longitudinal measurement of alpha and beta diversity and microbial species (gut microbiome) and 5hmc profiles with disease burden and response.

[0296] Justification:

[0297] • The exploratory correlative biology studies may provide insight into changes in the immune repertoire and disease burden before and after radiation as well as during anti-GD2 therapy and how this may be associated with response to therapy.

[0298] • Evaluation of potential of stool microbiome signatures and epigenetic profiles as a biomarker.

[0299] 4. STUDY DESIGN

[0300] 4.1. Overall design

[0301] This pediatric single arm, open label, phase 1 study will examine the safety and define the DLTs of SBRT combined with dinutuximab beta in high-risk patients with relapsed or refractory neuroblastoma. The study will determine safe doses of radiation by anatomic site in conjunction with dinutuximab beta. Additionally, preliminary data evaluating clinical utility in terms of overall response, response in non-radiated lesions (abscopal effect), and progression-free survival rate at 10 weeks will be assessed. The study will also provide the opportunity to explore changes in the tumor microenvironment induced by SBRT. Particularly, the inventor(s) will incorporate analysis of pretreatment (optional; if completed for clinical purposes) and posttreatment tumor biopsy specimens (optional). Biopsies will not be completed if a subject has abnormal coagulation studies or if deemed unsafe by the interventional radiologist. Additionally, longitudinal stool and blood samples will be taken and the gut microbiome (metagenomic shotgun sequencing) and blood-based biomarkers (cfDNA- 5hmc profiles) will be correlated with response and disease burden.

[0302] In week one, treatment will include radiation of 1-4 metastatic lesions in different sites via SBRT (Section 6.1.1). Dinutuximab beta (continuous intravenous infusion over 10 days at a daily dose of 10 mg / m2 / day) will be administered 3 days following the completion of SBRT. Patients without PD or DLT will receive additional cycles of antibody every 5 weeks [or adjusted based on weight]) for up to 12 cycles. Biopsies (optional), blood, and stool specimens will be collected prior to and after radiation. Additional blood and stool samples will be collected during the course of therapy after every 2 cycles of dinutuximab beta.

[0303] Toxicities will be assessed using CTCAEv5.0 with investigators using clinical judgment to determine attribution of toxicity to relevant organ systems. Dose-limiting toxicity (DLT) will be defined as Grade 3 or 4 (with certain exceptions as detailed in Section 6.1.3) deemed possible, probable, or definitely related to the treatment combination or for which the investigators deem further administration of dinutuximab beta as not safe. In any situations in which more than one organ system might be implicated, toxicity will be attributed to all that are relevant. Attribution of all Grade 3 or 4 toxicities will be reviewed in a weekly meeting of phase 1 investigators. DLTs that occur at treatment sites that were not radiated or do not appear to fit within the organ categories described in the treatment section will be categorized as "Other". Should 2 or more DLTs in the "Other" category be observed, accrual to the study will be placed on hold for detailed review of these toxicities. The circumstances and treatment of each patient (total body radiation dose, sites of disease, etc.) will be reviewed prior to considering the reopening of the study to accrual. Only two dose levels at each site will be evaluated (level 1, level -1).

[0304] As toxicities from radiation evolve over time, early toxicity data will be collected within 10 weeks from the start of SBRT . Late toxicity data will be collected starting 10 weeks after SBRT. If the initial radiation dose for an anatomic site is deemed toxic, a lower dose of radiation will be evaluated as per the treatment table (Section 6.1.1.1, Table 3: Prescription Doses) and statistical plan (Section 9.4.1).

[0305] Response will be calculated by the revised International Neuroblastoma Response Criteria (INRC)1. Additionally, response will be described as overall response rate (including radiated and non-radiated lesions) as well as response rate of non-radiated lesions as applicable (patient level response excluding radiated lesions).

[0306] 4.2. Scientific Rationale for Study Design This is a phase 1 study to determine the safety of the combination of stereotactic body radiotherapy (SBRT) and anti-GD2 therapy with dinutuximab beta in patients with refractory or recurrent high-risk neuroblastoma.

[0307] See Introduction, Sections 2.1 (Study Rationale) and 2.2.1 (Rationale for Research Design and Population).

[0308] 4.3. Justification for Dose

[0309] See Section 2.2.3 (Stereotactic Body Radiotherapy and Dinutuximab Beta: Dose Rationale).

[0310] 4.4. End of Study Definition

[0311] A participant is considered to have completed the study if he or she has completed all phases of the study including the last visit or the last scheduled procedure shown in the Schedule of Activities (SoA), Section 1.3. Participants can receive up to 12 cycles of dinutuximab beta on this study.

[0312] The end of the study is defined as completion of the last visit or procedure shown in the SoA in the trial globally.

[0313] 5. Study population

[0314] 5.1. Inclusion criteria

[0315] 5.1.1. Age

[0316] Patients must be > 1 year and < 30 years of age on the day of signing informed consent.

[0317] 5.1.2. Diagnosis and Risk groups

[0318] • Patients must have a diagnosis of neuroblastoma or ganglioneuroblastoma (nodular) either by histologic verification of neuroblastoma and / or demonstration of tumor cells in the bone marrow with increased urinary catecholamines [i.e. > 2 x upper limit of normal (ULN)] at the time of initial diagnosis.

[0319] • Patients must have been diagnosed with high-risk neuroblastoma according to the 2021 COG risk classification system52at the time of study enrollment. Patients with relapsed / refractory disease who were initially classified as low or intermediate risk, but reclassified as high risk are also eligible.

[0320] 5.1.3. Response to Prior Therapy

[0321] Recurrent / progressive or refractory neuroblastoma 5.1.4. Site of Disease and Disease Status

[0322] Patients must have one of the following at the time of enrollment:

[0323] • Measurable tumor by RECIST 1.1 (lesion can be accurately measured in at least one dimension with a longest diameter > 10 mm, or for discrete lymph nodes > 15mm on short axis) on MRI or CT scan that is MIBG avid or demonstrates increased FDG uptake on PET scan (for MIBG non-avid disease).

[0324] • MIBG-avid lesion detected on MIBG scan with positive uptake at a minimum of one site (e.g. osseous lesion). This site must represent disease recurrence after completion of therapy, progressive disease on therapy, or refractory disease.

[0325] • Patients with refractory soft tissue disease (measurable tumor by RECIST 1.1) that is not MIBG avid or does not demonstrate increased FDG uptake on PET scan must undergo biopsy to document the presence of viable neuroblastoma. Biopsy is not required for patients who have a new site of soft tissue disease (i.e. progression) regardless of whether progression occurs while receiving therapy or after completion of therapy.

[0326] Lesions situated in a previously irradiated area are considered measurable if progression has been demonstrated in such lesions.

[0327] At least one tumor lesion must meet the at least one of following criteria for SBRT radiation: o 0.25 cc to 65 cc of viable tumor (i.e. primary disease or metastases) approximately 5 cm in maximal dimension. Tumors larger than 65 cc can be partially treated if needed. o Metastases located in lung, liver, mediastinal / cervical nodes, spinal / paraspinal / osseous, abdominal-pelvic (lymph node / adrenal gland).

[0328] 5.1.5. Have a performance status as defined below:

[0329] • Lansky score > 60 for participants < 16 years (Appendix 1)

[0330] • Karnofsky score > 60 for participants >16 years of age (Appendix 1)

[0331] 5.1.6. Prior therapy

[0332] Participants must meet the following minimum duration from prior anti-cancer directed therapy prior to enrollment: • Cytotoxic chemotherapy or other anti-cancer agents known to be mvelosuppressive: > 21 days after the last dose of cytotoxic or myelosuppressive chemotherapy (42 days, if prior nitrosourea).

[0333] • Anti-cancer agents not known to be mvelosuppressive(e.g., not associated with reduced platelet or ANC counts): > 7 days after the last dose of agent.

[0334] • Antibodies: > 21 days from infusion of last dose, and toxicity related to prior antibody therapy must be recovered to Grade < 1.

[0335] • Hematopoietic growth factors: > 14 days after the last dose of a long-acting growth factor (e.g., Neulasta) or 7 days for short-acting growth factor.

[0336] • Interleukins, Interferons and Cytokines (other than Hematopoietic Growth Factors): >21 days after the completion of interleukins, interferon or cytokines.

[0337] • Autologous stem cell infusion fe.g. high-dose chemotherapy followed by autologous stem cell transplant or stem cell infusion as supportive care post 1-131 MIBG therapy): > 42 days

[0338] • Cellular Therapy: > 42 days after the completion of any type of cellular therapy (e.g., modified T cells, NK cells, dendritic cells, etc.)

[0339] • XRT / External Beam Irradiation: o > 14 days after local XRT; craniospinal XRT or if radiation to > 50% of the pelvis o > 42 days if other substantial bone marrow radiation

[0340] Note: Participants must have recovered from all radiation-related toxicities (< Grade 1 or at baseline), not require corticosteroids, and not have had radiation pneumonitis. A 1-week washout is permitted for palliative radiation (<2 weeks of radiotherapy) to non-CNS disease.

[0341] • Radiopharmaceutical therapy (e.g., radiolabeled antibody, I-131-MIBG): > 42 days after systemically administered radiopharmaceutical therapy. See also prior stem cell infusion requirements above.

[0342] 5.1.7. Concomitant Medication Restrictions

[0343] Refer to Section 6.7 for the concomitant therapy restrictions for patients during treatment.

[0344] 5.1.8. Patient recovery from previous treatment Patients must have recovered from all non-hematologic adverse events due to previous therapies to < Grade 1 or baseline with the following exceptions:

[0345] • Patients with < Grade 2 hypothyroidism are eligible

[0346] • Patients with < Grade 2 alopecia are eligible

[0347] • Patients with < Grade 2 CNS toxicity from prior therapy are eligible

[0348] 5.1.9. Major surgery

[0349] If participant received major surgery, they must have recovered adequately from the toxicity and / or complications from the intervention prior to starting study treatment.

[0350] 5.1.10. Organ Function Requirements

[0351] • Hematologic Function: Patients must meet the following hematologic criteria for enrollment regardless of bone marrow disease involvement. o ANC > 750 / uL (no short-acting hematopoietic growth factors within 7 days of blood draw documenting eligibility and no long-acting hematopoietic growth factors within 14 days of blood draw documenting eligibility); and o Platelet count > 50,000 / pl, transfusion independent (no platelet transfusions or platelet growth factors within 7 days of blood draw documenting eligibility).

[0352] Note: Patients known to have bone marrow involvement with neuroblastoma are eligible provided that minimum ANC and transfusion independent platelet count criteria are met (as above). However, these patients are not evaluable for hematological toxicity.

[0353] • Renal Function: o Measured or calculated creatinine clearance per institutional standard (GFR can also be used in place of creatinine or CrCI) > 70 mL / min / 1.73 m2or o A serum creatinine based on age / gender as follows:

[0354] The threshold creatinine values were derived from the Schwartz formula for estimating GFR53utilizing child length and stature data published by the CDC.

[0355] • Liver Function: o Total bilirubin < 1.5 x ULN for age AND o SGOT (AST) or SGPT (ALT) < 5x ULN for age (Note that for ALT, the upper limit of normal (ULN) for this protocol is defined as 45 U / L.).

[0356] • Adequate Pulmonary Function: o No evidence of dyspnea at rest, no exercise intolerance, no chronic oxygen requirement o If pulmonary function tests (PFTs) are performed, FEV1 / FVC must be > 60%

[0357] • Central Nervous System (CNS) Function: o Patients with a history of CNS disease must have no clinical or radiological evidence of active CNS disease at the time of study enrollment o Patients with seizure disorder may be enrolled if on non-enzyme- inducing anticonvulsants and well controlled.

[0358] • Cardiac Function: o Shortening fraction of > 27% by echocardiogram, or o Ejection fraction of > 50% by echocardiogram or radionuclide angiogram

[0359] 5.1.11. Reproduction function

[0360] • All post-menarchal females must have a negative serum or urine beta-HCG within 7 days prior to study enrollment.

[0361] • Male and female subjects of reproductive age and childbearing potential must agree to use two acceptable methods of birth control (i.e., a hormonal contraceptive, intra-uterine device, diaphragm with spermicide, condom with spermicide, or abstinence) or to abstain from heterosexual intercourse for the duration of their participation in the study, or for 3 months after last dose of protocol therapy, whichever is longer.

[0362] 5.1.12. Consent

[0363] The participant (and / or their parents or legal guardians, if applicable) provides written informed consent for the trial.

[0364] 5.2. Exclusion criteria

[0365] 5.2.1. Patients who are pregnant, breast feeding, or unwilling to use effective contraception during the study participation.

[0366] 5.2.2. Patients currently participating in a study of an investigational agent or receiving other ongoing anticancer therapy.

[0367] Patients who have entered the follow-up phase of an investigational study may participate as long as it has been at least 4 weeks after the last dose of the previous investigational agent and they meet the criteria for prior therapy listed under Inclusion Criteria (Section 5.1).

[0368] 5.2.3. Patients and / or families who, in the opinion of the investigator, may not be able to comply with the requirements of the study.

[0369] 5.2.4. Patients with disease of any major organ system that would compromise their ability to withstand therapy.

[0370] 5.2.5. Systemic Steroids and Immunosuppressive Medications

[0371] • Patients must have been off pharmacologic doses of systemic steroids for at least 7 days prior to enrollment.

[0372] • Patients who require or are likely to require pharmacologic doses of systemic corticosteroids while receiving treatment on this study are ineligible. The only exception is for patients known to require 2 mg / kg or less of hydrocortisone (or an equivalent dose of an alternative corticosteroid) as premedication for blood product administration in order to avoid allergic transfusion reactions.

[0373] Note: The use of conventional doses of inhaled steroids for the treatment of asthma is permitted, as is the use of physiologic doses of steroids for patients with known adrenal insufficiency. • Patients on any other immunosuppressive medications (e.g., cyclosporine, tacrolimus) are not eligible.

[0374] 5.2.6. Patients who only have bone marrow disease are not eligible for this study.

[0375] 5.2.7. Patients who have undergone prior allogeneic stem cell transplant.

[0376] 5.2.8. Patients who have received prior solid organ transplantation.

[0377] 5.2.9. Patients who have received prior total body irradiation.

[0378] 5.2.10. Patients with prior radiation therapy (defined as >10% of prior prescription dose) to the area planning to be treated with SBRT.

[0379] 5.2.11. Patients with a history of grade 4 allergic reactions to anti-GD2 antibodies or reactions that required discontinuation of the anti-GD2 therapy.

[0380] 5.2.12. Patients who are on hemodialysis.

[0381] 5.2.13. Patients with an active or uncontrolled infection.

[0382] 5.2.14. Patients with known history of human immunodeficiency virus (HIV), hepatitis B, or hepatitis C. (testing of patients not known to be infected with these viruses is not required prior to study enrollment).

[0383] 5.2.15. Patient with a known history of active TB (Bacillus Tuberculosis)

[0384] 5.2.16. Patients must not have been diagnosed with myelodysplastic syndrome or with any malignancy other than neuroblastoma.

[0385] 5.2.17. Patients with known active CNS metastases.

[0386] 5.2.18. Patients with a history of (non-infectious) pneumonitis that required steroids or has current pneumonitis.

[0387] 5.2.19. Patients with a history or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the study, interfere with the subject's participation for the full duration of the study, or is not in the best interest of the subject to participate, in the opinion of the treating investigator.

[0388] 5.3. Lifestyle considerations

[0389] Meals and Dietary Restrictions: Participants should maintain a normal diet unless modifications are required to manage an AE such as diarrhea, nausea or vomiting.

[0390] 5.4. Screen failures

[0391] Screen failures are defined as participants who consent to participate in the clinical trial but are not subsequently assigned to the study intervention or entered in the study. A minimal set of screen failure information is required to ensure transparent reporting of screen failure participants, to meet the Consolidated Standards of Reporting Trials (CONSORT) publishing requirements and to respond to queries from regulatory authorities. Minimal information includes demography, screen failure details, eligibility criteria, and any serious adverse event (SAE).

[0392] Individuals who do not meet the criteria for participation in this trial (screen failure) because of a lab abnormality may be rescreened. Rescreened participants should be assigned the same participant number as for the initial screening.

[0393] 6. Study interventions

[0394] 6.1. Study intervention(s) Administration: Stereotactic Body Radiotherapy followed by Dinutuximab beta

[0395] 6.1.1. Study intervention description: stereotactic body radiotherapy

[0396] Based on prior experience and clinical trials of SBRT (NRG-BR00132-34; NCT02608385- Merck investigator-initiated trial of SBRT + pembrolizumab in adults with advanced solid tumors25; NCT03431948- Bristol Myer-Squibb investigator-initiated phase 1 trial of SBRT + nivolumab + urelumab or cabiralizumab in adults with advanced solid tumors35), clinical trials of SBRT in the pediatric population (such as ARST1431 [NCT02567435]), and the most recently completed COG protocol for neuroblastoma (ANBL1531 [NCT03126916]), the following radiation therapy planning guidelines detailed in Sections 6.1.1.1-6.1.1.5 will be used. Only two dose levels at each site will be considered (level 1 and level -1). Radiation should begin as close as possible to the date on which treatment is allocated / assigned and should be completed no later than 14 days from enrollment.

[0397] Three days after completion of SBRT, treatment with dinutuximab beta (10 mg / m2 / day given continuously over 10 days) will be administered. Additional cycles will be administered every 5 weeks up to 12 cycles for eligible patients (Section 6.1.1). 6.1.1.1. Dose fractionation

[0398] Patients will receive 5 daily (Monday through Friday) fractions of radiation as determined by the location of the metastases to be irradiated. Radiation doses per organ are listed in Table 4. Table 4: Prescription Doses (LN=lymph node(s))

[0399] *doses are still consistent with hypofractionated RT but not extreme hypofractionated

[0400] RT ( i.e. SBRT)

[0401] 6.1.1.2. Daily Imaging Requirements

[0402] The minimum image-guided radiation therapy (IGRT) requirements for each metastatic location are listed in Table 4. Volumetric imaging refers to 3D modalities (e.g., kV conebeam, MV cone-beam, CT on rails), while orthogonal imaging refers to 2D modalities (e.g., kV OBI, ExacTrac). For volumetric imaging, appropriate CT window / level thresholds must be employed for registration at each metastatic location as outlined in Table 5: Minimum IGRT requirements for RT delivery. For example, static kV imaging at an undetermined breath hold position would not be adequate IGRT for treating a free-breathing lung tumor.

[0403] Table 5: Minimum IGRT requirements for RT delivery

[0404] 6.1.1.3. Treatment planning / target volumes

[0405] Metastasis Location Definition

[0406] For the primary endpoint analysis, each metastasis targeted with SBRT will be assigned to one of the 5 "Metastastatic Anatomic Sites" as described in Table 4. Dose fractionation will differ for each metastatic location as shown in Table 5.

[0407] Metastatic Locations:

[0408] Luna:

[0409] GTV within the lung parenchyma. Due to the dose delivered, no distinction is made between central and peripheral lung lesions.

[0410] Mediastinal / Cervical LN:

[0411] Mediastinal Lymph Nodes: GTV arising within the anatomic space between the lungs, above the diaphragm, and below the thoracic inlet at the level of the top of the sternal notch.

[0412] Cervical Lymph nodes: GTV occurring within cervical lymph node Levels I-VI and / or retropharyngeal spaces

[0413] Liver: GTV arising within the liver.

[0414] Spinal: Metastases will be assigned to the spinal / paraspinal site if the GTV arises within the vertebral bodies expanded by 2 cm. To minimize the risk of scoliosis, the CIV should be adjusted to include uniform dose to the entire corresponding vertebrae, including the vertebral body, transverse and spinous processes, and pedicles, even if they are non-uniformly involved by disease. The entire vertebral body should receive >18 Gy if it is to be treated. Metastases arising in the ribs within 2 cm of the edge of the vertebral body should be included in the spinal metastasis location but osseous metastases planning guidelines are to be used.

[0415] Osseous: GTV arising within an osseous structure, part of the axial skeleton, not included in the spinal definition.

[0416] • Calvarial and base of skull metastases: CTV should be adjusted to avoid extension into cerebral cortex unless the lesion extends through the skull with suspected dural involvement. If the entire calvarium must be treated, a brain sparing approach, such as that used by Wolden, et al.54should be used.

[0417] • Limb metastases: Adjust CTV to avoid circumferential limb treatment, growth plates, and joint spaces (unless involved). Treatment of lesions involving the capital femoral epiphysis should be avoided, due to the risk of slipped capital femoral epiphysis. If a lesion involves a growth plate (aside from capital femoral epiphysis), the growth plate should receive a reduced dose of 17 Gy in 5 fractions, while the part of the lesion not involving the growth plate may receive 20 Gy in 5 fractions. This dose to the growth plate has an equivalent BED (biologically effective dose) to standard dose regimens of 21.6 Gy in 12 fractions, using an alpha / beta of 4.5. The alpha / beta of growth plates has been suggested as 4.5 per Rao, et al55.

[0418] • Rib metastases that are within 1 cm of the vertebral bodies will be classified into the spinal metastasis location given the similar normal tissues at risk.

[0419] • Rib metastases CTV will be adjusted such that CTV does not extend into the lung parenchyma unless there is strong evidence of parietal pleura involvement

[0420] • Sternal metastases will be considered part of the mediastinal / cervical lymph nodes location given the similar normal tissues at risk.

[0421] Abdominal-pelvic: GTV arising within the anatomic space defined by the diaphragm superiorly, the genitourinary diaphragm inferiorly including the peritoneal and retroperitoneal spaces, not including liver, osseous, or spinal metastases.

[0422] 6.1.1.4. Dosimetry

[0423] Target Volume Definition Based on Metastatic Location: Specific RT planning parameters depend on the location of the treated metastasis as well as the mechanism used for motion management / evaluation. The table below (Table 6) defines appropriate planning CT window / leveling, recommended additional modality scans to be fused, as well as how to define the GTV, ITV, CTV, and PTV for each metastatic location. Only rigid registration will be permitted for multi-modality fusion. In general, the GTV is defined as the entirety of the metastasis as seen on planning CT scan aided by additional diagnostic imaging studies (e.g., MIBG or MRI). Use of additional diagnostic studies is left to the discretion of the treating physician. The CTV=GTV; there is no margin added for microscopic extension. In general, either a helical CT or 4DCT will be used for defining the GTV / ITV depending upon the tumor motion encountered, although both scans may be acquired at the time of simulation. Typically, the ITV is generated using either expiratory / inspiratory phase scans or from reconstructed maximum intensity projection (MIP) scans. Maximum / minimum intensity projections (MIP / MinIP) should be used with caution because the MIP reconstruction for lung or MinIP reconstruction for liver may erroneously define an ITV in cases of significant irregular breathing or when tumors abut soft tissue structures (e.g., the diaphragm for MIP) or fat (for the MinIP).

[0424] Table 6: Metastatic Location and PTV

[0425]

[0426] 6.1.1.5. Organs at risk (oar) planning constraints Table 7 lists maximum dose limits to a point or volume within several critical organs based on the dose fractionation schema (five fractions) assigned based on metastatic tumor location.

[0427] The spinal cord, lung, heart, esophagus, stomach, duodenum, jejunum / ileum, and bowel doses are absolute limits, and treatment delivery that exceeds these limits will constitute a major protocol violation. However, some OAR (i.e., the esophagus, trachea proximal bronchial tree, great vessels and heart within the lung) may be situated adjacent to the treated GTV / PTV. As such, there is no specified limit as tumors that are immediately adjacent to that organ will not be able to be treated to any of the prescription doses without irradiating a small volume of that organ to the prescribed dose.

[0428] A nonadjacent structure will be generated for each of the following organs: esophagus, trachea proximal bronchial tree, and great vessels. The nonadjacent wall corresponds to the half circumference of the tubular structure not immediately touching the GTV or PTV. These contours would start and stop superiorly and inferiorly just as with the named structure. The half lumen of the structure should be included in this contour.

[0429] In cases where more than half of the structure's lumen is directly touching the GTV or PTV, then the more conservative approach will be adopted, and the full organ cross section will be used as nonadjacent in those CT slices.

[0430] The planning needs to be done so that there is no hot spot within that organ, even if that organ is part of the GTV / PTV, i.e., that no part of any OAR receives more than 105% of the prescribed dose. In addition, the volume of the OAR in question needs to be minimized, both in length and in width (i.e., circumference), with efforts made to reduce the dose to the contralateral wall of the organ.

[0431] For non-spinal cord organs at risk with known sensitivity to high doses of radiation (including the bowel, esophagus, and stomach) included within a PTV or immediately adjacent to PTVs, a prescription dose at the lower end of acceptable variation should be used. Additionally, every effort should be made to cover the GTV with the prescription dose while ensuring rapid falloff to the organ at risk. Coverage of a section of PTV including or immediately adjacent to the OAR may be as low as 70% of the prescription dose ONLY in this situation. Since the tumor and normal tissue may not allow strict avoidance, the larger volume limits will not be scored as protocol Deviations Unacceptable if exceeded. Primary coverage goal is that 95% of PTV should be covered by 95% of the prescription dose. If this cannot be achieved, then secondary coverage goal requires that 99.5% of the PTV should be covered by 70% of the prescription dose. Table 7: OAR Dose Limits for 5 fraction RT .1.2. Study intervention description: Dinutuximab beta 6.1.2. 1. Dose timing

[0432] Three days after the completion of SBRT (5 fractions, Monday-Friday), cycle 1 of dinutuximab beta will be administered over 10 days (i.e. the Monday after completion of radiation). Additional cycles of dinutuximab beta will be given every 5 weeks (cycle length: 35 days) up to 12 cycles.

[0433] • Cycle 1: For delays due to scheduling / administrative reasons, Cycle 1 of dinutuximab beta may be started up to 7 days from the completion of radiation if it cannot be initiated 3 days after completion of the last fraction of radiation.

[0434] • Cycle 2+: Trial treatment may be administered + / - 3 days Day 1 of each cycle for scheduling or administrative reasons.

[0435] • Patients will undergo tumor evaluations (CT or MRI;123I-MIBG [or18FDG PET for patients with MIBG non-avid disease]; bilateral bone marrow aspirates and biopsies) after every 2 cycles of dinutuximab beta

[0436] Trial treatment should be administered after all procedures / assessments have been completed as detailed on the Schedule of Activities (Section 1.3 and 8.1). All treatment parameters must be met before starting each cycle of dinutuximab beta (Section 6.1.2.2).

[0437] 6.1.2.2. Criteria to begin each cycle of Dinutuximab beta

[0438] Hematologic parameters: o ANC > 750 / .L o Platelet count > 50,000 / gL (transfusion independent for > 7 days).

[0439] ALT < 5 x ULN for age provided that the usual causes of transaminitis such as infections, tumor progression, or drug toxicity are excluded by appropriate blood and imaging studies AND the transaminitis is stable if not improving. For the purposes of this study, ULN for ALT is 45 U / L.

[0440] Total bilirubin < 1.5 x ULN for age

[0441] No evidence of serious infection, or infection under control (e.g., negative blood culture).

[0442] A serum creatinine based on age / sex as described in Section 5.1 (Inclusion Criteria)

[0443] 6.1.2.3. Dose administration

[0444] Table 8: Dinutuximab Beta Treatment

[0445] *Dosina of dinutuximab beta will be as follows31:

[0446] Each dose is calculated based on the body surface area (BSA) or body weight as follows:

[0447] • Patients > 12 kg are dosed based on the BSA: 10 mg / m2 / day

[0448] • Patients < 12 kg are dosed according to their body weight: 0.33 mg / kg / day

[0449] While radiation treatments will be completed in the outpatient setting, administration of dinutuximab beta will occur in the inpatient setting.

[0450] 6.1.2.4. Premedication and supportive care recommended for prevention of anticipated toxicities associated with dinutuximab beta

[0451] Neuropathic pain, allergic reactions, and fever are commonly seen in patients receiving this antibody. Institutional guidelines for supportive care during this portion of therapy should be followed. The use of the following premedications is recommended:

[0452] • Pain management: o To reduce opiate requirements during dinutuximab beta therapy, gabapentin dosing is recommended. To optimize the effect of gabapentin, it should be initiated 1 week prior to expected start of antibody so that it can be increased to full dose by the start of dinutuximab beta administration. Dosing should follow institutional standards; however, the following dosing may be considered:

[0453] ■ First day of gabapentin: 5 mg / kg / dose (max 300 mg / dose) at bedtime

[0454] ■ Second day of gabapentin: 5 mg / kg / dose (max 300 mg / dose) BID ■ Third day of gabapentin: 5 mg / kg / dose (max 300 mg / dose) TID - patients should be at this dose by the time of admission for Cycle 1 dinutuximab beta

[0455] ■ Gabapentin doses can be increased further if necessary; institutional guidelines should be followed. o Use of a patient-controlled analgesia device (PCA) or continuous opioid infusion during the dinutuximab beta infusion is recommended. Morphine is the most commonly administered opioid. Hydromorphone or fentanyl may be used in patients with known indications for use of hydromorphone or fentanyl. Recommended starting dose of analgesics:

[0456] ■ Morphine 0.1 mg / kg / dose 20 minutes prior to initiation of the first dinutuximab beta infusion. At the same time, start a continuous morphine infusion of 0.02 mg / kg / hr with bolus doses of 0.01 mg / kg / dose ql5 minutes prn for pain.

[0457] ■ If hydromorphone PCA is used, it is recommended to start the hydromorphone pre-infusion dose of 0.02 mg / kg / dose 20 minutes prior to starting the infusion of the first dinutuximab beta infusion. At the same time, start a continuous hydromorphone infusion of 0.004 mg / kg / hr (maximum initial rate: 0.2 mg / hour for opioid naive patients) with bolus doses of 0.002 mg / kg / dose ql5 minutes prn for pain.

[0458] ■ If fentanyl PCA is used, it is recommended to start fentanyl 1 mcg / kg 10 minutes prior to starting the first infusion of dinutuximab beta. At the same time, start a continuous fentanyl infusion of 0.5 micrograms / kg / hr with bolus doses of 0.25 micrograms / kg / dose qlO minutes prn pain.

[0459] ■ Doses should be titrated as needed in accordance with institutional guidelines. o For patients unable to use a PCA, a continuous basal infusion of morphine (or alternative medication) and as-needed boluses of the same medication may be used. Starting doses of the basal infusion and boluses should be based on patient weight, institutional standard practices, and doses required by individual patients for treatment of pain associated with previous interventions. Doses should be titrated as needed in accordance with institutional guidelines.

[0460] • IV hydration: Administer NS 10-20 mL / kg IV over 60-90 minutes just prior to first dinutuximab beta infusion. • Diphenhydramine 1 mg / kg / dose (maximum 50 mg) IV / PO 20 minutes prior to dinutuximab beta infusion and scheduled q6h. Hydroxyzine PO (0.5-1.0 mg / kg; max dose 50 mg) may be used instead of diphenhydramine in patients for whom there is a specific indication.

[0461] • Consider use of cetirizine for patients with a history of allergic reactions

[0462] • Famotidine: 0.5 mg / kg (max: 40 mg / day) IV 20 minutes prior to dinutuximab beta infusion and scheduled ql2h or equivalent H2 antagonist

[0463] • Acetaminophen PO / IV: 15 mg / kg / dose (maximum 650 mg) 20 minutes prior to each dinutuximab beta infusion and scheduled q4-6h prn.

[0464] • Fluid shifts and increased insensible volume losses due to fever are commonly seen in patients receiving dinutuximab beta. In addition to the IV saline bolus given immediately prior to the start of dinutuximab beta, the administration of maintenance IV fluids should be considered. Fluids can be adjusted as needed based on intravascular volume status.

[0465] • Have immediately available during the dinutuximab beta infusion: o Albuterol and oxygen o Epinephrine o Hydrocortisone: Use only for life-threatening reactions (hypotension, bronchospasm, angioedema involving the airway) not responsive to other measures.

[0466] • Monitoring during the dinutuximab beta infusion: o Check vital signs every 15 minutes for the first hour; if stable check vitals hourly x 2 hours and then every 4 hours until dinutuximab beta infusion is complete o Strict intake and output every 4 hours o Call front line clinician for:

[0467] ■ Altered blood pressure (refer to baseline values for patient and normal values for age / gender / height of patient), tachycardia, tachypnea, fever

[0468] ■ Pain requiring an increase in narcotic infusion rate, urticaria, bronchospasm, peripheral / sensory neurotoxicity, new persistent cough

[0469] 6.1.2.5. Dose modifications and toxicity management recommendations

[0470] 6.1.2.5.1. Hypotension

[0471] • Treatment of dinutuximab beta-induced severe hypotension (without evidence of allergic reaction) o If hypotension is severe and accompanied by poor perfusion, end organ dysfunction, or acidemia - Pediatric Advanced Life Support (PALS) guidelines should be followed and dinutuximab beta infusion should be discontinued.

[0472] • Treatment of *moderate hypotension (without poor perfusion, end organ dysfunction or acidemia): o Immediately hold dinutuximab beta o Give normal saline bolus (20 mL / kg as rapidly as possible) o Stop or adjust doses of narcotics and sedating Hl blockers o Consider use of Trendelenberg position o If hypotension persists after the above measures have been taken:

[0473] ■ Reassess perfusion and end organ function

[0474] ■ Follow PALS algorithm if indicated

[0475] ■ Repeat NS bolus OR

[0476] ■ Consider use of albumin if albumin < 3 gm / dL

[0477] ■ Consider use of PRBCs if Hb < 8 gm / dL

[0478] ■ Consider use of platelets if count <50,000 / pL

[0479] ■ Consider transfer to the intensive care setting o If hypotension persists following 2 volume boluses, give an additional bolus and prepare to administer pressors: epinephrine or norepinephrine is preferred over dopamine, if possible

[0480] *Note: Moderate Hypotension is defined as:

[0481] Symptomatic decreases in blood pressure (BP) and / or

[0482] Systolic BP < 5th percentile based on age and height and baseline BPs OR

[0483] Systolic or diastolic BP decreased by > 20% below baseline

[0484] • Resumption of dinutuximab beta o For patients whose hypotension resolves promptly and completely with limited volume resuscitation (< 40 mL / kg) and without requirement for pressor support, dinutuximab beta may be restarted at 50% of the previous infusion rate. If blood pressures are stable for 2 hours, the infusion may be given at full rate for the remainder of that day and subsequent days. If the patient again experiences hypotension requiring multiple volume boluses (e.g., > 40 mL / kg) when dinutuximab beta is given at full rate, but the patient tolerates the 50% infusion rate, then the remaining dinutuximab beta should be given at 50% rate of the initial infusion rate.

[0485] ■ If blood pressures are stable for 2 hours after resumption of dinutuximab beta at the reduced rate, the remainder of the antibody infusion may be given at the full rate.

[0486] ■ If hypotension recurs at the reduced rate, the measures above should again be taken and no further dinutuximab beta should be given that day. The antibody infusion may be restarted the following day after ensuring that the patient is volume replete. The antibody rate upon resumption of treatment should be 50% of the initial rate. If blood pressures are stable for 2 hours, the infusion may be given at full rate for that day and subsequent days. If the patient's blood pressures are only stable at the 50% rate and not at full rate, then the remaining dinutuximab beta for that day and doses on subsequent days should be given at 50% of the initial infusion rate. For patients who require multiple volume boluses for hemodynamic stabilization, dinutuximab beta should be resumed the following day at 50% of the initial infusion rate.

[0487] ■ If blood pressures are stable for 2 hours after resumption of dinutuximab beta at the reduced rate, the remainder of the antibody infusion may be given at the full rate.

[0488] ■ If hypotension recurs at the reduced rate, the measures above should again be taken and no further dinutuximab beta should be given that day. The antibody infusion may be restarted the following day after ensuring that the patient is volume replete. The antibody rate upon resumption of treatment should be 50% of the initial rate. If blood pressures are stable for 2 hours, the infusion may be given at full rate for that day and subsequent days. If the patient's blood pressures are only stable at the 50% rate and not at full rate, the remaining dinutuximab beta should be given at the 50% rate of infusion. For patients who require pressors for treatment of hypotension, if blood pressure is stable off pressors for at least 6 hours, administration of dinutuximab beta may be resumed at 50% of the initial infusion rate on the day following the hypotensive episode. Care should be taken to ensure that the patient is volume replete. Dinutuximab beta should not be given to patients who continue to require pressor support. Patients who require pressor support for > 24 hours due to treatment-related hypotension despite appropriate volume resuscitation should discontinue protocol therapy. Patients who again require pressor support when dinutuximab beta is resumed must discontinue protocol therapy.

[0489] 6.1.2.5.2. Treatment of allergic reactions / infusion reactions

[0490] Mild allergic reactions / infusion reactions to dinutuximab beta infusion: o A mild allergic reaction is limited to rash, flushing, urticaria, mild dyspnea - Grade 1 or 2 o The following recommendations do NOT apply to Grade 3 or 4 allergic reactions, including anaphylaxis o Management

[0491] ■ Decrease rate of dinutuximab beta to 50% of full rate

[0492] ■ Perform serial exams at bedside

[0493] ■ Administer Hl blocker (diphenhydramine, cetirizine recommended)

[0494] ■ Administer H2 blocker

[0495] ■ When symptoms resolve, resume original infusion rate

[0496] ■ If symptoms recur when original rate is resumed, decrease to 50% rate again

[0497] Moderate to severe allergic reactions / infusion reactions to dinutuximab beta infusion:

[0498] • Moderate to severe reactions include any of the following: symptomatic bronchospasm, allergy-related edema / angioedema, hypotension, or anaphylaxis - Grade 3 or 4

[0499] • The following recommendations do NOT apply to Grade 1 or 2 allergic reactions

[0500] • Management o Immediately hold dinutuximab beta o Assess airway, breathing and circulation o Follow institutional guidelines for rapid response team notification if clinically indicated o For airway concerns

[0501] ■ Administer oxygen and albuterol immediately for bronchospasm

[0502] ■ Administer IV diphenhydramine

[0503] ■ Administer epinephrine (1: 1000 IM recommended) immediately if upper airway involved or if airway issues are accompanied by cardiovascular collapse

[0504] ■ Administer IV hydrocortisone (1-2 mg / kg) if the patient has frank anaphylaxis with cardiorespiratory collapse OR if > 2 doses of epinephrine are required OR if moderate to severe symptoms recur upon rechallenge with dinutuximab o For hypotension in the setting of allergic reaction

[0505] ■ Give normal saline bolus (20 mL / kg as rapidly as possible)

[0506] ■ Stop or adjust doses of narcotics and sedating Hl blockers

[0507] ■ Consider use of Trendelenberg position

[0508] ■ See previous section for management of persistent hypotension o For patients with mild bronchospasm or angioedema that does not impact breathing and completely resolves without the use of epinephrine and hydrocortisone and for patients whose hypotension resolves following volume bolus, dinutuximab beta may be resumed at 50% of the previous rate of infusion on the same day the reaction occurred. If symptomatic angioedema or asymptomatic bronchospasm recurs when the dinutuximab beta is restarted, discontinue immunotherapy for that day and if symptoms / signs resolve completely that day, resume the next day with additional pre-medication of hydrocortisone 1-2 mg / kg IV. For this rechallenge, the infusion should be given in an ICU setting. o For patients whose bronchospasm or angioedema requires the use of systemic epinephrine, protocol therapy must be discontinued. o For patients with bronchospasm or angioedema that does not require systemic epinephrine but whose hypotension requires more extensive volume resuscitation, guidance in Section 6.1.2.5.1 should be followed.

[0509] 6.1.2.5.3. Management of capillary leak syndrome (> grade 3)

[0510] • Hold dinutuximab beta infusion

[0511] • Provide oxygen, fluids as needed

[0512] • Diuretics should be used with caution and hypotension avoided • See Section 6.1.2.5.1 for management of hypotension, anemia and hypoalbuminemia.

[0513] • Do NOT resume dinutuximab beta therapy if symptoms of severe capillary leak syndrome persist on the same day or subsequent days of a given cycle. Only resume dinutuximab beta therapy when the capillary leak syndrome resolves or requires less significant intervention (Grade 2 or less).

[0514] • If capillary leak resolves, may resume dinutuximab beta infusion at 50% rate the same day and for subsequent doses during a given cycle. The infusion may be given at the full rate at the start of subsequent cycles.

[0515] • If mechanical ventilation (any duration) or pressor support for > 24 hours is required due to therapy-related capillary leak syndrome, the patient must discontinue protocol therapy.

[0516] 6.1.2.5.4. Management of renal insufficiency (unrelated to hypotension)

[0517] • Consider the possibility of renal hypoperfusion in the context of borderline hypotension; administer volume if appropriate.

[0518] • If the patient's creatinine is elevated to > 2 x the upper limit of normal (ULN) for age / gender (refer to eligibility criteria) and elevation persists despite optimized fluid management, hold dinutuximab beta.

[0519] • Modify dosing of concomitant medications that may contribute to or be affected by renal insufficiency.

[0520] • When urine output returns to normal and creatinine returns to < 2 x ULN for age / gender, resume dinutuximab beta at 50% rate. If renal function normalizes by the following day, dinutuximab beta may be administered at full rate. If renal function is not sufficiently improved (urine output normal and creatinine < 2x ULN for age / gender) by Day 7, no further dinutuximab beta should be given during that cycle of therapy. If renal function has normalized by the planned start date for the next cycle, retreatment with dinutuximab beta is permitted.

[0521] 6.1.2.5.5. Management of hyponatremia (> grade 3; na < 130 meq / l and symptomatic or 120-124 meq / l regardless of symptoms)

[0522] • Change hypotonic fluids to isotonic fluids as compatibilities permit

[0523] • Avoid administration of oral free water

[0524] • Correct fluid losses due to diarrhea • 3% saline is only indicated in the following settings: o hyponatremia leading to seizure o drop in sodium level > 10 points in 6 hours or less o sodium level < 117 mEq / L

[0525] • If Grade 4 hyponatremia persists despite optimal fluid management, discontinue dinutuximab beta for the remainder of the cycle. Sodium should be monitored closely during the next cycle of therapy. If hyponatremia improves to Grade 2 or better, or to baseline, empiric dose reduction is not required at the start of the next cycle of therapy; though dinutuximab beta would again be discontinued if Grade 4 hyponatremia were to persist despite optimal fluid management. In such cases, patient must discontinue protocol therapy.

[0526] 6.1.2.5.6. Management of fever in the absence of hypotension

[0527] • Administer antipyretics

[0528] • Adjust fluids to account for insensible losses if fever is persistent

[0529] • Obtain blood culture

[0530] • Administer empiric antibiotics if suggested by institutional policy

[0531] 6.1.2.5.7. Management of treatment-related pain

[0532] No further dinutuximab beta therapy should be given to patients who experience treatment related Grade 3 pain that cannot be controlled by narcotics during a given cycle. Treatment with gabapentin or similar agent should be initiated if not already being administered. If pain that is not controlled with narcotics recurs during a subsequent cycle, the patient should discontinue protocol therapy.

[0533] For patients with treatment-related Grade 3 pain requiring intravenous narcotics for > 48 hours following completion of dinutuximab beta therapy, gabapentin or similar agent should be initiated if not already being administered. If pain requiring prolonged intravenous narcotics (>48 hours following completion of dinutuximab beta therapy) recurs during a subsequent cycle despite this intervention, the patient must discontinue protocol therapy.

[0534] 6.1.2.5.8. Management of visual changes

[0535] Dinutuximab beta may cause impaired accommodation and / or dilated pupils with sluggish light reflex with or without photophobia. No dose modifications, dose reductions, or changes in infusion rate should be made unless there is associated vision loss. If this occurs in conjunction with Grade 3 decrease in vision, dinutuximab beta must be discontinued. If visual loss improves to Grade 1 or better before the next immunotherapy cycle is due, the patient should receive dinutuximab beta at a dose that is 50% reduced compared to the prior dose. If the lower dose of dinutuximab beta is tolerated without worsening of ocular toxicity, full dose dinutuximab beta should be given in subsequent cycles. If visual toxicity worsens, the patient must discontinue protocol therapy.

[0536] Dose reductions for dilated pupils or changes in accommodation without vision loss are not required.

[0537] 6.1.2.5.9. Management of serum sickness

[0538] Identification of serum sickness - signs and symptoms include arthralgias / arthritis, splenomegaly, lymphadenopathy, glomerulonephritis in the presence of persistent fevers, cutaneous eruptions.

[0539] Serum sickness typically develops 1 to 3 weeks after administration of the causative agent, but can develop within 12-36 hours in patients who have previously been sensitized to the causative agent.

[0540] Patients with > Grade 3 serum sickness must discontinue protocol therapy.

[0541] For Grade 2 serum sickness, antihistamines should be prescribed.

[0542] 6.1.2.5.10. Management of neurotoxicity

[0543] Patients who develop Grade 4 neurotoxicity should discontinue protocol therapy.

[0544] Dinutuximab beta must be discontinued for the remainder of the current cycle of therapy for patients who develop Grade 3 sensory neuropathy or Grade 3 motor neuropathy. If abnormalities resolve by start of next cycle of therapy, the patient may receive 50% dose of dinutuximab beta. If symptoms do not completely resolve or recur with dinutuximab beta then the patient must discontinue protocol therapy.

[0545] 6.1.3. Dose limiting toxicity

[0546] Toxicity will be graded using the CTCAE criteria, version 5. The CTCAE provides descriptive terminology and a grading scale for each adverse event listed. A copy of the CTCAE can be downloaded from the CTEP home page (ctep.cancer.gov).

[0547] 6.1.3.1. Definition of evaluable for toxicity

[0548] Evaluable patients for toxicity will be defined as any eligible patient who begins protocol SBRT treatment for a given metastatic location: 1-lung; 2- mediastinal / thoracic (axillary or cervical) lymph node; 3-liver; 4- spinal / paraspinal / osseous; 5-abdominal- pelvic metastases (lymph node; adrenal gland). 6.1.3.2. Definition of dose limiting toxicity

[0549] Dose limiting toxicity (DLT) will be defined as any grade 3 or 4 AE that is possibly, probably, or definitely attributable to study regimen (with the exceptions listed below). Only DLTs that occur from the start of radiotherapy and within the first 10 weeks of dinutuximab beta (2 cycles) will be used for determination of the R.P2D of SBR.T, although all DLTs during any cycle will be reported. Only dose levels will be evaluated (level 1 and -1).

[0550] Certain frequently observed side effects known to be related to dinutuximab beta are transient, and can be well-controlled clinically. These transient side effects, if well- controlled clinically, will not be used in this study to determine dose limiting toxicity. Additionally, certain expected toxicities associated with radiation will not be used to determine dose limiting toxicity.

[0551] Non-hematological DLTs:

[0552] Non-hematologic dose-limiting toxicity is defined as any grade 3 or 4 non-hematologic toxicity that is possibly, probably, or definitely attributable to the combination of therapy, with the exception of the following:

[0553] • Skin related adverse events (CTCAE Grade 0-3) in the absence of desquamation or mucosal involvement that resolve to grade 0-1 within 3 weeks of intervention and do not require systemic steroids.

[0554] • Adverse events affecting skin, mucosal surfaces, or any organ in the radiation field that are expected to resolve to CTCAE grade 0-1 within 3 weeks of treatment without requiring systemic steroids

[0555] • Grade 3 fever

[0556] • Grade 3 nausea or vomiting

[0557] • Grade 3 infection

[0558] • Grade 3 febrile neutropenia

[0559] • Grade 3 fatigue lasting <72 hours

[0560] • Pupillary dilation and / or accommodation defects not accompanied by vision loss

[0561] • Grade 3 pain that resolves to < grade 2 within 72 hours

[0562] • Grade 3 diarrhea that resolves to < grade 1 with supportive care within 5 days • Grade 4 fevers (ie. Temp > 40°C) during dinutuximab beta administration that resolves within 48 hours of dinutuximab beta completion

[0563] • Grade 3 skin toxicity (urticaria) during dinutuximab beta infusion that improves to < grade 2 with treatment (e.g. diphenhydramine) within 48 hours

[0564] • Grade 3 urine output decreased that resolves within 24 hours of completion of dinutuximab beta

[0565] • Grade 3 proteinuria that returns to < grade 1 within 5 days of completion of dinutuximab beta

[0566] • Grade 3 weight gain that resolves to < grade 2 within 3 days of completion of dinutuximab beta

[0567] • Grade 3 weight loss or anorexia that resolves to < grade 2 within 3 days

[0568] • Grade 3 dehydration that resolves to < grade 2 within 3 days

[0569] • Grade 3 electrolyte abnormality (Na, K, Cl, CO2, Ca, Mg, PO4) that resolves to

[0570] < grade 2 within 3 days with or without treatment

[0571] • Grade 3 hypoalbuminemia

[0572] • Grade 3 hypotension and grade 3 hypertension that resolves to < grade 1 within 48 hours

[0573] • Grade 4 hypotension associated with dinutuximab beta that resolves to < grade 2 with supportive care not including pressors

[0574] • Grade 4 hypotension associated with dinutuximab beta that resolves to < grade 2 with supportive care not including pressors

[0575] • Grade 3 or grade 4 AST that returns to < grade 2 within 7 days

[0576] • Grade 3 or grade 4 ALT that returns to < grade 2 within 7 days [Note: The ALT

[0577] ULN = 45 U / L on this study]

[0578] • Grade 3 GGT; Grade 4 GGT that returns to < grade 2 within 7 days

[0579] • Grade 3 bilirubin elevation that returns to < grade 2 within 7 days

[0580] • Grade 3 or grade 4 alkaline phosphatase elevation that returns to < grade 2 within 7 days

[0581] • Grade 3 neurotoxicity (i.e. interference with function plus objective weakness) will not be a DLT if transient and reversing within 3 days of completion of dinutuximab beta for any course, or within 2 weeks of completion for grade 3 sensory changes interfering with daily activities. Subjective findings (e.g. tingling, hot or cold hands, taste change, etc.) are expected and will not be a DLT.

[0582] • Grade 3 allergic reactions or anaphylaxis that is readily controlled with supportive anti-allergic (non-steroidal) treatments (i.e. diphenhydramine, epinephrine)

[0583] • Grade 3 capillary leak syndrome

[0584] • Grade 3 cough, dyspnea, hypoxia and bronchospasm that decrease to < grade 2 within 72 hours

[0585] • Grade 3 or grade 4 somnolence that resolves to < grade 2 on stopping supportive care medications (ie; narcotics, diphenhydramine, meperidine, etc.) during dinutuximab beta

[0586] • Grade 3 capillary leak syndrome that does not persist for more than one week

[0587] Hematologic DLTs:

[0588] Hematologic dose-limiting toxicity will be defined as platelet count or neutrophil decreases that result in a delay of greater than 14 days for beginning subsequent courses of therapy because of drug-related myelosuppression.

[0589] Patients with known bone marrow metastatic disease will be eligible for this study but will not be evaluable for hematologic DLT. An additional patient will be added if a patient is taken off protocol therapy for hematological toxicity with bone marrow disease.

[0590] 6.2. Preparation / handling / storage / accountability of dinutuximab beta

[0591] 6.2.1. Formulation, appearance, packing and labeling:

[0592] Dinutuximab beta (Qarziba) 4.5 mg / mL concentrate for solution for infusion.

[0593] • The concentrate is a colorless to slightly yellow clear solution provided in 6 mL sterile glass vials with rubber stoppers and caps containing 4.5 mL.

[0594] • Concentration: 4.5 mg / mL

[0595] • Each 4.5 mL vial contains 20 mg dinutuximab beta.

[0596] • Excipients: 20 mM histidine, 5% sucrose, 0.01%, Polysorbate 20

[0597] • The drug product must be diluted before administration.

[0598] 6.2.2. Product storage and stability Product Storage

[0599] • Refrigerated, 2°C to 8°C, protected from light

[0600] Shelf-life

[0601] • Concentrate: 36 months

[0602] • Solution: Dinutuximab beta solution for infusion is for immediate use only. Post- reconstitution / dilution of the product, the solution for infusion must not be stored for more than 4 hours at 2-8°C before initiation of infusion. From a physicochemical point of view, in-use stability has been demonstrated for up to 48 hours at 25°C (50 mL syringe) and for up to 7 days at 37°C (250 mL infusion bag).

[0603] 6.2.3. Preparation

[0604] The solution for infusion must be prepared under aseptic conditions. The solution must not be exposed to direct sunlight or heat.

[0605] The patient-specific daily dose of dinutuximab beta is calculated based on body surface area. Dinutuximab beta should be diluted aseptically to the patient-specific concentration / dose with sodium chloride 9 mg / mL (0.9%) solution for infusion, containing 1% human albumin (e.g. 5 mL of human albumin 20% per 100 mL sodium chloride solution).

[0606] • For continuous infusions, the solution for infusion can be prepared freshly on a daily basis, or sufficient for up to 5 days of continuous infusion. The daily dose is 10 mg / m2. The amount of solution to be infused per day (within a treatment course of 10 consecutive days) should be 48 mL; with 240 mL for a 5-day dose. It is recommended to prepare 50 mL solution in a 50 mL syringe, or 250 mL in an infusion bag suitable for the employed infusion pump, i.e. an overfill of 2 mL (syringe) or 10 mL (infusion bag) to allow for dead volumes of the infusion systems.

[0607] • For repeated daily infusions, the daily dose is 20 mg / m2 and the calculated dose should be diluted in 100 mL sodium chloride 9 mg / mL (0.9%) containing 1% human albumin.

[0608] 6.3. Measures to minimize bias: randomization and blinding

[0609] Randomization and blinding: not applicable

[0610] This is an open-label trial; therefore, the Principal Investigator, sub-investigators and subject will know the treatment administered.

[0611] 6.4. Registration procedures Prior to registration / enrollment and any study-specific evaluations being performed, all patients must have given written informed consent for the study and must have completed the pre-treatment evaluations. Patients must meet all of the eligibility requirements as described in Sections 5.1 and 5.2.

[0612] 6.5. Treatment allocation

[0613] Evaluable patients will be defined as any eligible patient who begins protocol SBRT treatment for a given metastatic location. Individual patients may be deemed to contribute to evaluation of multiple organ sites. For example, if a patient has liver and lymph node metastases, evaluation of toxicities in each of these sites (in addition to general toxicity assessment) could occur.

[0614] 6.6. Concomitant therapy

[0615] 6.6.1. Chemotherapy or immunomodulating agents

[0616] No other systemic anti-cancer or immunomodulatory therapy (including steroids) will be permitted. Pharmacologic doses of systemic corticosteroids should be used ONLY for life-threatening conditions (i.e. life-threatening allergic reactions and anaphylaxis such as bronchospasm, stridor) unresponsive to other measures. The use of dexamethasone as an anti-emetic is not permitted. Corticosteroid therapy can be used as a premedication for transfusion in patients known to have a history of transfusion reactions or for treatment of an unexpected transfusion reaction (hydrocortisone 2 mg / kg or less or an equivalent dose of an alternative corticosteroid). Physiologic doses of steroid for patients with known adrenal insufficiency is acceptable. The use of steroids during protocol therapy requires clear justification and documentation.

[0617] 6.6.2. External beam radiotherapy

[0618] Radiotherapy outside of protocol therapy is prohibited.

[0619] 6.6.3. Cytokines or growth factors

[0620] Cytokines or growth factors (G-CSF, Interferon, etc.) not included in the treatment plan are prohibited during protocol therapy.

[0621] 6.6.4. Rescue medicine

[0622] Refer to Sections 6.1.2.4 (Premedication and Supportive Care for Prevention of Anticipated Toxicities) and 6.1.2.5 (Dose Modifications and Toxicity Management Recommendations).

[0623] 7. Study intervention discontinuation and participant discontinuation / withdrawal 7.1. Discontinuation of study intervention (protocol therapy)

[0624] Discontinuation from protocol therapy does not mean discontinuation from the study, and remaining study procedures should be completed as indicated by the study protocol. If a clinically significant finding is identified (including, but not limited to changes from baseline) after enrollment, the investigator or qualified designee will determine if any change in participant management is needed. Any new clinically relevant finding will be reported as an adverse event (AE).

[0625] • Participants (or parents / guardians) are free to withdraw from or refuse protocol therapy at any time upon request.

[0626] • An investigator may discontinue or withdraw a participant from protocol therapy for the following reasons: o Completion of protocol therapy o Pregnancy o Significant study intervention non-compliance o Development of second malignancy o If any clinical adverse event (AE), laboratory abnormality, or other medical condition or situation occurs such that continued protocol therapy would not be in the best interest of the participant o Disease progression o If the participant meets an exclusion criterion (either newly developed or not previously recognized) that precludes further protocol therapy o Participant unable to receive study treatment for >10 weeks, due to an adverse event or other intervention o Initiation onto another therapeutic study and / or another anti-cancer therapy

[0627] Reason for discontinuation / withdrawal of protocol therapy will be collected and recorded in the case report form (CRF). Participants who are off protocol therapy are to be followed until they meet the criteria for Off Study (Section 7.2). Follow-up data will be required unless a patient is taken off study.

[0628] When a participant discontinues / withdraws prior to trial completion, all applicable activities scheduled for the final trial visit should be performed at the time of discontinuation. The End of Treatment and Follow-up visit procedures are listed in Section 1.3 (SoA) and Section 8.1.7.3. After the end of treatment, each subject will be followed for 30 days for adverse event monitoring (serious adverse events will be collected for 90 days after the end of treatment) as described in Section 8.2.5 Time Period and Frequency For Event Assessment and Follow-up. Subjects who discontinue for reasons other than progressive disease will have post-treatment follow-up for disease status until disease progression, initiating a non-study cancer treatment, withdrawing consent, or becoming lost to follow-up. After documented disease progression each subject will be followed by telephone for overall survival until death, withdrawal of consent, or the end of the study, whichever occurs first.

[0629] 7.2. PARTICIPANT DISCONTINUATION / WITHDRAWAL FROM STUDY (OFF STUDY CRITERIA)

[0630] Off Study Criteria include:

[0631] • Death

[0632] • Lost to follow-up

[0633] • Patient / Parent withdrawal of consent

[0634] • Patient never received protocol therapy

[0635] • Completion of study, including follow-up period

[0636] Reason for withdrawal from study will be collected and recorded in the CRF.

[0637] 7.3. Lost to follow-up

[0638] A participant will be considered lost to follow-up if he or she fails to return for three scheduled visits and is unable to be contacted by the study site staff.

[0639] The following actions must be taken if a participant fails to return to the clinic for a required study visit:

[0640] • The site will attempt to contact the participant and reschedule the missed visit within 7 days and counsel the participant on the importance of maintaining the assigned visit schedule and ascertain if the participant wishes to and / or should continue in the study.

[0641] • Before a participant is deemed lost to follow-up, the investigator or designee will make every effort to regain contact with the participant (where possible, 3 telephone calls and, if necessary, a certified letter to the participant's last known mailing address or local equivalent methods). These contact attempts should be documented in the participant's medical record or study file. • Should the participant continue to be unreachable, he or she will be considered to have withdrawn from the study with a primary reason of lost to follow-up.

[0642] 7.4. Participant replacement strategy

[0643] Evaluable participants will be defined as any eligible participant who begins protocol SBRT for a given metastatic location. A participant that discontinues the trial for progressive disease or a drug-related AE will not be replaced and will be counted in the evaluable population of participants for the respective cohort. A participant may be replaced if he / she withdraws consent prior to receiving the first dose of SBRT.

[0644] 8. STUDY ASSESSMENTS AND PROCEDURES

[0645] 8.1. Trial procedures

[0646] The Schedule of Activities - Section 1.3 and Appendix 5 summarizes the trial procedures to be performed at each visit. Individual trial procedures are described in detail below. It may be necessary to perform these procedures at unscheduled time points if deemed clinically necessary by the investigator.

[0647] Furthermore, additional evaluations / testing may be deemed necessary for reasons related to participant safety. In some cases, such evaluation / testing may be potentially sensitive in nature, and thus local regulations may require that additional informed consent be obtained from the participant. In these cases, such evaluations / testing will be performed in accordance with those regulations.

[0648] 8.1.1. Administrative procedures

[0649] 8.1.1.1. Informed consent

[0650] The Investigator must obtain documented consent from each potential participant prior to participating in a clinical trial.

[0651] 8.1.1.2. Inclusion / exclusion criteria

[0652] All inclusion and exclusion criteria will be reviewed by the investigator or qualified designee to ensure that the participant qualifies for the trial.

[0653] 8.1.1.3. Demographics and Medical History

[0654] Demographics and medical history will be obtained by the investigator or a qualified designee. Medical history will include all active conditions and any condition diagnosed within the prior 10 years that are considered to be clinically significant by the Investigator. Details regarding the disease for which the participant has enrolled in this study will be recorded separately and not listed as medical history.

[0655] 8.1.1.4. Prior and Concomitant Medications Review 8.1.1.4.1. Prior Medications

[0656] The investigator or a qualified designee will review prior medication use, including any protocol-specified washout requirement, and record prior medication taken by the participant 28 days before starting the trial. Treatment for the disease for which the participant has enrolled in this study will be recorded separately and not listed as a prior medication.

[0657] 8.1.1.4.2. Concomitant Medications

[0658] The investigator or a qualified designee will record medication, if any, taken by the participant during the trial. All medications related to reportable serious adverse events (SAEs) and events of special interest should be recorded as defined in Sections 8.2.7 and 8.2.9, respectively.

[0659] 8.1.1.5. Disease Details and Treatments

[0660] 8.1.1.5.1. Disease Details

[0661] The investigator or a qualified designee will obtain prior and current details regarding disease status.

[0662] 8.1.1.5.2. Prior Treatment Details

[0663] The investigator or a qualified designee will review all prior cancer treatments including systemic treatments, radiation and surgeries.

[0664] 8.1.1.5.3. Subsequent Anti-Cancer Therapy Status

[0665] The investigator or a qualified designee will review all new anti-neoplastic therapy initiated after the last dose of trial treatment. If a participant initiates a new anticancer therapy within 30 days after the last dose of trial treatment, the 30-day Safety Follow-up visit must occur before the first dose of the new therapy. If a Safety Followup visit cannot be completed, the investigator must document the reason (e.g. participant is urgently receiving new anticancer therapy). Once new anti-cancer therapy has been initiated the participant will move into survival follow-up.

[0666] 8.1.1.6. Trial Compliance (Medication / Diet / Activity / Other)

[0667] Interruptions from the protocol specified treatment plan for greater than 10 weeks between dinutuximab beta doses due to toxicity require consultation between the investigator and the Principal Investigator and written documentation of the collaborative decision on subject management.

[0668] The total volume of trial treatment infused will be compared to the total volume prepared to determine compliance with each dose administered. Administration of medication will be documented per Institutional guidelines. The instructions for preparing and administering dinutuximab beta will be provided in the Pharmacy Manual.

[0669] 8.1.2. Clinical Procedures / Assessment

[0670] 8.1.2.1. Adverse Event (AE) Monitoring

[0671] The investigator or a qualified designee will assess each participant to evaluate for potential new or worsening AEs as specified and more frequently if clinically indicated. Adverse experiences will be graded and recorded throughout the study and during the follow-up period according to version 5.0 of the CTCAE of the National Cancer Institute (NCI) for toxicity and performance reporting. Toxicities will be characterized in terms regarding seriousness, causality, toxicity grading, and action taken with regard to trial treatment. Additionally, toxicities are to be reported on the appropriate case report forms. Note: 'CTCAE v5.0' is understood to represent the most current version of CTCAE v5.0 as referenced on the CTEP website (i.e., v5.02 and all subsequent iterations prior to version 6.0).

[0672] A copy of the CTCAE version 5.0 can be downloaded from the CTEP website

[0673] (ctep. cancer. gov / protocolDevelopment / electronic_applications / ctc. htm) .

[0674] Detailed information regarding the assessment and recording of AEs is described in Section 8.2.

[0675] 8.1.2.2. Full Physical Exam

[0676] The investigator or a qualified designee will perform a complete physical exam during Screening, on Day 1 of each cycle of dinutuximab beta, and during tumor assessments at the end of each even cycle of therapy, End of Treatment, Safety follow-up, and Follow-up visits. Clinically significant abnormal findings should be recorded as medical history.

[0677] 8.1.2.3. Directed Physical Exam

[0678] The investigator or a qualified designee will perform a directed physical exam as clinically indicated on each day of radiation, during each day of inpatient hospitalization for administration of dinutuximab beta (i.e. Days 1-11 of each cycle or longer if inpatient hospitalization is extended).

[0679] 8.1.2.4. Vital Signs

[0680] The investigator or a qualified designee will take vital signs at screening, during each day of radiation, and Day 1 of each cycle of dinutuximab beta. Additional vitals will be obtained during administration of dinutuximab beta per institutional standards for administration of anti-GD2 antibody and routine inpatient monitoring.

[0681] Vital signs should include temperature, pulse, respiratory rate, blood pressure, and oxygen saturation.

[0682] Height and weight will be collected during Screening, the first day of each dinutuximab beta cycle, during tumor assessments at the end of each even cycle of therapy, End of Treatment, Safety follow-up, and Follow-up visits.

[0683] 8.1.2.5. Electrocardiogram and Echocardiogram

[0684] Echocardiogram and electrocardiogram (12-lead ECG) should be performed at the Screening visit only. Electrocardiogram (6-lead-ECG) is acceptable in accordance with local standard of care. Clinically significant abnormal findings should be recorded in the medical history.

[0685] 8.1.2.6. Performance Status (Age-Appropriate Performance Scale)

[0686] The investigator or a qualified designee will assess performance status according to an age-appropriate scale (see Appendix 1) at screening, on Day 1 of each cycle of dinutuximab beta, during tumor assessments at the end of each even cycle of therapy, End of Treatment, Safety follow-up, and Follow-up visits.

[0687] Use of performance scale is dependent upon age: Lansky Scale in children up to and including 16 years of age and Karnofsky Scale for adolescents and young adults >16 years of age. The performance scale used for a given subject at baseline will be the performance scale followed throughout the study.

[0688] 8.1.3. Laboratory Procedures / Assessments

[0689] Details regarding specific laboratory procedures / assessments to be performed in this trial are provided in the SoA (Section 1.3).

[0690] Laboratory tests for hematology, chemistry, urinalysis, and others are specified in Appendix 2

[0691] Screening:

[0692] Required laboratory tests should be performed within 7 days prior to enrollment.

[0693] Pre-Radiotherapy:

[0694] Urine pregnancy test (or serum pregnancy test) up to 72 hours prior to Day 1 of radiotherapy for those of child bearing potential. During therapy: Cycle 1+ Dinutuximab beta:

[0695] Laboratory assessments to proceed with each cycle of dinutuximab beta can be conducted up to 72 hours prior to Day 1 of each cycle. o Results must be reviewed by the investigator or a qualified designee and found to be acceptable prior to the start of trial treatment.

[0696] • After Day 1 of each cycle, additional daily laboratory assessments will occur Days 2-11 of each cycle.

[0697] • Laboratory assessments will occur weekly on Days 15 (+ / - 3 days) and 22 (+ / - 3 days), and between days 29-35 of each cycle.

[0698] Laboratory assessments will be completed at end of treatment, safety follow-up, and follow-up visits.

[0699] 8.1.4. T umor Assessments

[0700] Tumor disease evaluations include appropriate imaging studies to encompass all sites of metastatic disease, bilateral bone marrow aspirates, and biopsy for standard histology. Imaging studies will include cross sectional imaging (CT or MRI) and123I- MIBG scintigraphy. Participants with MIBG non-avid disease will undergo18FDG-PET Scintigraphy instead of123I-MIBG scintigraphy. Brain imaging, if performed to document the stability of existing metastases at Screening, should be by MRI if possible. If MRI is medically contraindicated, CT with contrast is an acceptable alternative. For participants without a history of brain metastases, head imaging is not required.

[0701] Imaging will be completed during the following timepoints (Section 1.3, SoA):

[0702] • Screening (baseline): Within 21 days prior to study

[0703] • During therapy: After every 2 cycles of dinutuximab beta (days 29-35 of each even cycle; can be completed between days 22-28 for administrative reasons or scheduling).

[0704] • End of Treatment and Follow-up: o In participants who discontinue study treatment, tumor imaging should be performed at the time of treatment discontinuation (±4-week window). If previous imaging was obtained within 4 weeks prior to the date of discontinuation, then imaging at treatment discontinuation is not mandatory. In participants who discontinue study treatment due to documented disease progression, this is the final required tumor imaging. o In participants who discontinue study treatment without documented disease progression, every effort should be made to continue monitoring their disease status by tumor imaging (every 8 weeks + / - 7 days x 1 year and then every 12 weeks + / - 7 days) to monitor disease status until the start of a new anticancer treatment, disease progression, pregnancy, death, withdrawal of consent, or the end of the study, whichever occurs first.

[0705] 8.1.4. 1. Evaluation of Bone Marrow

[0706] Bilateral bone marrow aspirates and biopsies will be completed per institutional standards.

[0707] 8.1.4.2. Cross Sectional Imaging

[0708] MRI or CT will be utilized for optimum visualization of all areas of bulk tumor (primary [if applicable] and metastases).

[0709] 8.1.4.2.1. MRI Scans

[0710] Typically, an MRI will be performed on 1.5 T or 3 T MRI units per institutional standard. Axial and at least 1 additional plane (coronal or sagittal) of the primary tumor will be performed using at least 2 pulse sequences (Tl, T2, STIR, FLAIR, in / out phase, post contrast). The radiologist performing the study will determine the appropriateness of the use of intravenous gadolinium (0.2 mL / kg). Slice thickness will be determined by patient size and region covered, but should be less than 7 mm. The smallest appropriate coil should be used. The longest diameter of the primary tumor will be recorded at baseline. Serial measurements of the primary tumor will include assessment of tumor size in the same orthogonal plane at the time of each evaluation.

[0711] 8.1.4.2.2. CT Scans

[0712] Axial imaging of the site of the primary tumor will be performed using low-dose technique according to the ALARA (As Low As Reasonably Achievable) concept. The studies will be performed using current-generation single or multi-detector systems. CT slice thickness should be 5 mm or less. Imaging will be performed during the administration of intravenous contrast, whenever possible, generally at 2 mL / kg. The use of oral contrast will be determined by the individual radiologist performing the study, but may be helpful in abdominal imaging. Images will be reconstructed in soft tissue and edge-enhanced bone / lung and liver algorithms. Coronal and sagittal multiplanar reconstructions may be helpful. As noted in the preceding section, serial measurements of the primary tumor will include assessment of tumor size in the same orthogonal plane at the time of each evaluation. MRI is superior to CT in characterizing epidural tumor extension or leptomeningeal disease, and is the preferred imaging modality in such cases (neck, chest, nonadrenal retroperitoneum) with spinal cord or canal encroachment.55It may also be useful in evaluating an MIBG-avid focus detected in the skeleton or soft tissues. With the exceptions noted above, the choice of MRI or CT will be left to the referring radiologist.

[0713] 8.1.4.3.123I-MIBG Scintigraphy

[0714] 8.1.4.3.1. Procedure

[0715] Dose: 5.2 MBq / kg or 0.14 mCi / kg; maximum 370MBq57or 10 mCi

[0716] Scintigraphy: Performed to obtain both planar and tomographic images. For planar imaging, anterior and posterior spot views from the top of the head to the distal lower extremities are obtained for 10 minutes each at approximately 24 hours after injection and may be done up to 48 hours after injection. A large field of view dual-head gamma camera with medium-energy collimators is preferred. A whole-body planar acquisition can be performed with a suggested scan rate of 5 cm / s. Additional orthogonal spot views of the head are recommended.

[0717] SPECT imaging with123I-MIBG is recommended when available, and should be performed approximately 24 hours after injection using a single or multiheaded camera with low-energy collimator. Institutional guidelines regarding data acquisition and reconstruction should be followed. MIBG-SPECT or MIBG-SPECT / CT may be used; however, the same imaging methodology should be used for all evaluations other than the post-therapy scan that follow131I-MIBG treatment.

[0718] 8.1.4.3.2. Thyroid Blockade

[0719] Potassium iodide will be administered to reduce thyroid accumulation of free radioiodine. A recommended regimen is 13% KI (100 mg iodide / mL) to be administered daily beginning on the day prior to radionuclide injection, and continuing daily for a total of 5 days. Dose is by weight; 1.2 mg iodine / kg (4 mg / drop).

[0720] 8.1.4.4.18FDG-PET Scintigraphy

[0721] It is recommended that the PET scan be performed following count recovery, if possible, in order to minimize the likelihood that augmented marrow signal is related to colony stimulating factor effect / marrow recovery.

[0722] The patient should be fasted for at least 4 hours prior to injection of FDG. Plasma glucose should be checked and, if the patient is substantially hyperglycemic, the study should be rescheduled when adequate glucose control has been established. FDG is administered intravenously per institutional guidelines. Good hydration is required as the primary route of FDG excretion is renal. The patient should drink water or receive intravenous fluids after injection to promote urinary FDG excretion. After injection, the patient is kept at rest for 45-60 minutes and imaging is then performed. The FDG dose range for a PET / CT scan is 3.7-5.2 MBq / kg (0.1-0.14 mCi / kg) and for a PET / MR scan is 2.59 -3.7 MBq (0.07 to 0.1 mCi / kg). The patient should void his / her bladder immediately prior to imaging if he / she is continent of urine. Whole body imaging (including extremities) should be obtained using institutional techniques.

[0723] Because of the short physical half-life of 1.8 hours and the high photon energy of 511 keV, FDG imaging may follow MIBG (either 1-123 or 1-131) or a MUGA study on the same day. If needed, the FDG imaging may be performed on the day preceding the MUGA.

[0724] Imaging with a dedicated PET / CT or PET / MR camera is preferred, but imaging with a stand-alone PET scanner is acceptable.

[0725] The FDG-PET study is processed for display by an iterative reconstruction algorithm. FDG activity should be corrected for attenuation, scatter, and radioactive decay. Attenuation correction is necessary, as apparent uptake will otherwise vary with depth of the lesion in the body and the nature of surrounding tissues. The procedure used for attenuation correction should be recorded. The level of tumor uptake is assessed subjectively by visual inspection and semi-quantitatively by determination of SUV. Uptake time, glucose levels, and partial volume effects influence both methods. The SUV method is also dependent on body weight and correction of SUV by normalizing for body surface area (BSA) reduces this dependency on body weight. Small lesions may have underestimated SUVs due to partial volume averaging effects. To calculate the SUV, a region of interest (ROI) should be carefully drawn around the area of elevated FDG uptake in the lesion to minimize partial volume effects. The SUV should be calculated as SUVBSA= ROI activity concentration (nCi / cc) X BSA / injected activity (nCi). The BSA is calculated from body mass (kg) and height (cm) using an appropriate algorithm. The SUVBSA for each measured lesion should be recorded and the technique for assessing SUVBSA should be consistent on follow-up studies. SUV measurements are directly available on almost all PET / CT display programs using simple ROIs.

[0726] PET may be performed in combination with CT on dual modality PET / CT scanners or in combination with MRI on dual modality PET / MR scanners. Typically, attenuation correction imaging (low-dose, non-contrast-enhanced CT, contrast-enhanced CT) is performed from the neck through the pelvis with the patient breathing shallow, followed by emission imaging at 3-5 minutes per bed position PET / MR simultaneous scanner or PET / MR sequential scanner attenuation correction will be performed using MR based attenuation correction techniques. Data are reconstructed as described above. Non-attenuation corrected and attenuation corrected PET data should be submitted for both PET / CT and PET / MR. For PET / CT, CT images should be submitted. For PET / MR, 3D T1 and axial T2 images should be submitted. Coronal fluid sensitive sequences can also be submitted if acquired.

[0727] 8.1.5. Efficacy Assessments: Response Criteria

[0728] This study will use the 2017 International Neuroblastoma Response Criteria1for disease assessment. The updated response criteria incorporate current approaches to imaging of neuroblastoma, including functional imaging. Furthermore, a standardized approach to assessment of bone marrow involvement is included. The current INRC do not include methods of disease assessment that are less sensitive and / or specific for neuroblastoma ("Tc bone scan and catecholamine levels).

[0729] 8.1.5. 1. Key Sites and Terms

[0730] 8.1.5.1.1. Primary Site

[0731] Primary site: The primary site will be identified as a measurable lesion > 10 mm in diameter as assessed by cross sectional imaging (CT or MRI scan). Primary site measurements must be recorded in millimeters (or decimal fractions of centimeters). The longest diameter of the primary tumor will be recorded at baseline. Serial measurements of the primary tumor will include assessment of tumor size in the same orthogonal plane at the time of each evaluation.58In patients with bilateral adrenal lesions, response will be based on the sum of the longest dimensions of both adrenal lesions unless biopsy proves one to be ganglioneuroma rather than neuroblastoma / ganglioneuroblastoma. In patients with multi-focal non-adrenal disease, the largest tumor will be considered the primary tumor. Response in additional lesions will be assessed as described below for metastatic lesions.

[0732] Tracer avidity (123I-MIBG or FDG-PET) in the primary site will be recorded at baseline. The scan appropriate for serial disease assessments should be used at each disease re-evaluation time point (e.g.,123I-MIBG avid primary lesions should be followed using123I-MIBG scans during therapy).

[0733] 8.1.5.1.2. Malignant Lymph Nodes

[0734] Malignant lymph nodes: To be considered pathologically enlarged and measurable, a metastatic lymph node must be > 15 mm in short axis when assessed by CT or MRI scan (CT scan slice thickness recommended to be no greater than 5 mm). At baseline and in follow-up, only the short axis of a discreet lymph node will be measured and followed as per RECIST criteria. Patients with neuroblastoma may have conglomerate masses of non-discrete lymph nodes (i.e. multiple contiguous retroperitoneal nodes). When a short axis of a discreet node cannot be identified, a lymph node conglomerate can be measured using the longest diameter of the composite lesion. Tracer avidity of metastatic nodes will be recorded at baseline and during disease evaluations.

[0735] For the purposes of response assessment, target lesions are disease sites that are measurable (non-nodal soft tissue mass > 10 mm in longest dimension or lymph node > 15 mm in short axis) and tracer avid OR are biopsy positive for neuroblastoma or ganglioneuroblastoma. The sum of diameters of target lesions is defined as the sum of the short axis of discrete lymph nodes (i.e., cervical, axillary nodes) added to the sum of the longest diameters of non-lymph node soft tissue metastases.

[0736] 8.1.5.1.3. Non-measurable Disease

[0737] All other lesions (or sites of disease), including small lesions (longest diameter < 10 mm or pathological lymph nodes with > 10 to < 15 mm short axis), are considered non-measurable disease. Bone lesions, leptomeningeal disease, and ascites, pleural / pericardial effusions are considered non-measurable.

[0738] 8.1.5.1.4. Bone Lesions

[0739] Osteomedullary disease will be assessed using123I-MIBG scans or FDG-PET scans. Technitium bone scans are no longer used as part of the revised INRC and are not included as part of disease reassessments during this trial. The extent of tracer avid disease will be evaluated using the Curie scoring system (see Appendix 3 for worksheet). SPECT may be used to confirm the presence or absence of lesions in a given segment of the body. The absolute Curie score should be reported at baseline. A relative score (Curie score at the time of disease assessment divided by baseline Curie score) should be recorded at the time of each disease evaluation.

[0740] 8.1.5.1.5. Bone Marrow Disease

[0741] Bilateral bone marrow aspirates and trephine biopsies are required at disease assessment time points. The extent of marrow involvement in all four samples should be recorded. Use of immunohistochemical staining for evaluation of trephine biopsies is strongly encouraged. The percentage of tumor infiltration of bone marrow space is assessed by histologic evaluation of trephine / biopsies or by counting the number of tumor cells in aspirates by cytology or immunocytology (recommended if available) divided by the number of hematopoietic / mononuclear cells evaluated to obtain a percentage involvement (methodology described by Burchill et al.).59The bone marrow sample with the highest percentage of tumor infiltration is used for response assessment. If > 0% to < 5% tumor infiltration is the highest percentage seen among samples obtained, the result should be recorded as minimal marrow disease.

[0742] 8.1.5.2. Response Criteria (2017 INRC)

[0743] 8.1.5.2.1. Primary Soft Tissue Response1Table 9: Primary Soft Tissue Response

[0744] 1Not for use in assessment of metastatic sites

[0745] 2For123I-MIBG non-avid tumors

[0746] 3A mass that has not met PD measurement criteria but has fluctuating123I-MIBG avidity will not be considered progressive disease. 8.1.5.2.2. Response at Metastatic Soft Tissue and Bone Sites

[0747] Table 10: Response at Metastatic Soft Tissue and Bone Sites

[0748] 1Used for MIBG non-avid tumors

[0749] 2Sum of diameters is defined as the sum of the short axis of discrete lymph nodes (i.e., cervical, axillary nodes) added to the sum of the longest diameters of non-lymph node soft tissue metastases. Masses of conglomerate non-discrete lymph nodes will be measured using longest diameter.

[0750] 3For patients with soft tissue metastatic disease, resolution of MIBG and / or FDG-PET uptake at the soft tissue sites is not required; all size reduction criteria must be fulfilled.

[0751] 4Relative Curie score at the time of subsequent disease evaluations is the absolute score for the bone lesions at the time of the current response assessment divided by the absolute score for bone lesions at the timepoint at which the absolute score was lowest (i.e., current absolute score divided by best absolute score achieved during therapy). MIBG-SPECT or MIBG-SPECT / CT may be used for scoring purposes but the same imaging methodology should be used for all evaluations.

[0752] 8.1.5.2.3. Bone Marrow Response Table 11: Bone Marrow Response immunohistochemistry strongly encouraged

[0753] 8.1.5.2.4. Determination of Overall Response

[0754] Table 12: Determination of Overall Response NI = Not involved, site not involved at study entry and remains not involved

[0755] MD = Minimal Disease, for bone marrow assessment only

[0756] Additional information regarding overall response assessment is described in Appendix 4. 8.1.6. Correlative Biology Studies

[0757] 8.1.6.1. Summary of Correlative Biology Studies

[0758] The following table outline the requirements for tissue, blood, and stool banking. These will be collected and stored for batched future analysis. Table 13: Correlative Biology Samples

[0759]

[0760]

[0761] 8.1.6.2. Pathology Review

[0762] All tumor biopsy tissue will be reviewed by a pathologist to verify the presence of tumor cells for those who undergo a research biopsy (optional).

[0763] 8.1.7. Visit Requirements

[0764] 8.1.7.1. Screening

[0765] The Screening Period will last 21 days. Tumor disease evaluations ( Section 8.1.4, Tumor Assessments) and non-laboratory screening procedures (Section 8.1.1, Administrative Procedures; Section 8.1.2, Clinical Procedures / Assessments) must occur within 21 days from allocation / enrollment. Laboratory assessments must occur within 7 days from allocation / enrollment. Allocation / enrollment will occur after the participant completes a screening visit with the pediatric oncologist and generally the same day as consultation with the radiation oncologist if all eligibility criteria are met. Upon allocation / enrollment, SBRT simulation planning will be scheduled and completed. This will be followed by treatment with SBRT and subsequently dinutuximab beta as detailed Section 6 (Study Intervention).

[0766] The full schedule of activities is described in appendix 5.

[0767] 8.1.7.2. Treatment Period

[0768] • SBRT should begin as close as possible to the date on which treatment is allocated / assigned and be completed no later than 14 days from enrollment.

[0769] • Participants will be seen daily in Duchossois Center for Advanced Medicine (DCAM) for SBRT over the course of 1 week (5 fractions, Monday-Friday)

[0770] • Treatment with dinutuximab beta will be initiated 3 days after completion of the last fraction of radiation (i.e. the Monday after completion of radiation). Up to 12 cycles will be administered. o Cycle length = 35 days (5 weeks) o Cycle 1: For delays due to scheduling / administrative reasons, Cycle 1 of dinutuximab beta may be started up to 7 days from the completion of radiation. o Cycle 2+: Trial treatment may be administered + / - 3 days from the scheduled Day 1 of each cycle for scheduling or administrative reasons. o Participants will be evaluated on Day 1 of each cycle in the Comer Children's Hospital outpatient clinic and subsequently be admitted to begin treatment with dinutuximab beta. o Dinutuximab beta will be administered inpatient on days 1-10 (infusion ends day 11) and patients will be evaluated / monitored at least daily.

[0771] • Patients will undergo tumor evaluations (CT or MRI;123I-MIBG [or18FDG PET for patients with MIBG non-avid disease; bilateral bone marrow aspirates and biopsies) after every 2 cycles of dinutuximab beta. o Tumor evaluations will be completed during days 29-35 of each cycle (tumor evaluations can be completed during days 22-28 for scheduling or administrative reasons).

[0772] The full schedule of activities is described in appendix 5.

[0773] 8.1.7.3. End of Treatment Visit

[0774] The full schedule of activities is described in appendix 5. The discontinuation of study Intervention and Tumor Assessment are described in sections 7.1 and 8.1.4.

[0775] If the End of Treatment visit coincides with the end of the 12thcycle of therapy, then this additional visit is not needed. If a patient discontinues protocol therapy as a result of disease progression during scheduled tumor assessments, that visit will also serve as the End of Treatment visit.

[0776] 8.1.7.4. Post-Treatment Visits

[0777] 8.1.7.4.1. Safety Follow-Up Visit

[0778] The mandatory Safety Follow-Up Visit should be conducted approximately 30 days after the last dose of study treatment or before the initiation of a new anti-cancer treatment, whichever comes first. All AEs that occur prior to the Safety Follow-Up Visit should be recorded. Participants with an AE of Grade > 1 will be followed until the resolution of the AE to Grade 0-1 or until the beginning of a new anti-cancer therapy, whichever occurs first. SAEs that occur within 90 days of the end of treatment or before initiation of a new anti-cancer treatment should also be followed and recorded.

[0779] 8.1.7.4.2. Follow-up Visits

[0780] Participants who discontinue study treatment for a reason other than disease progression will move into the Follow-Up Phase and should be assessed every 8 weeks (56 ± 7 days) by radiologic imaging, bilateral bone marrow aspirates, and biopsies to monitor disease status. After 1 year, the imaging time point will occur every 12 weeks (84 ± 7 days). Every effort should be made to collect information regarding disease status until the start of new anti-cancer therapy, disease progression, death, or end of the study. Information regarding post-study anti-cancer treatment will be collected if new treatment is initiated.

[0781] 8.1.7.4.3. Survival Follow-up

[0782] Participants who experience confirmed disease progression or start a new anticancer therapy, will move into the Survival Follow-Up Phase and should be contacted by telephone every 12 weeks to assess for survival status until death, withdrawal of consent, or the end of the trial, whichever occurs first.

[0783] 8.1.8. Adverse Events and Serious Adverse Events

[0784] 8.1.8.1. Purpose

[0785] Adverse event data collection and reporting, which are required as part of every clinical trial, are done to ensure the safety of patients enrolled in the studies as well as those who will enroll in future studies using similar agents. Adverse events are reported in a routine manner at scheduled times during a trial. Additionally, certain adverse events must be reported in an expedited manner to allow for timelier monitoring of patient safety and care.

[0786] Adverse events will be graded according to the NCI Common Terminology Criteria for Adverse Events (CTCAE), Version 5. A copy of the CTCAEv5 can be downloaded from the CTEP home page (ctep.cancer.gov).

[0787] 8.1.8.2. Definition of Adverse Events (AE)

[0788] An adverse event is any problematic or unfavorable medical occurrence in a human subject, including any abnormal sign (e.g. abnormal physical exam or laboratory finding), symptom, or disease, temporally associated with the subject's involvement in the research, whether or not considered related to participation in the research.

[0789] 8.1.8.3. Definition of Serious Adverse Events (SAE) An adverse event (AE) or suspected adverse reaction is considered "serious" if, in the view of either the investigator or sponsor, it results in any of the following outcomes:

[0790] • Death

[0791] • Life-threatening adverse event, or places the subject at immediate risk of death from the event as it occurred

[0792] • Inpatient hospitalization or prolongation of existing hospitalization

[0793] • A persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions

[0794] • Congenital anomaly / birth defect.

[0795] • important medical events important medical events are those that may not result in death, be life-threatening, or require hospitalization but may be considered serious when, based upon appropriate medical judgment, they may jeopardize the participant and may require medical or surgical intervention to prevent one of the outcomes listed in this definition. Examples of such medical events include allergic bronchospasm requiring intensive treatment in an emergency room or at home, blood dyscrasias or convulsions that do not result in inpatient hospitalization, or the development of drug dependency or drug abuse.

[0796] 8.1.8.4. Classification of an Adverse Event

[0797] 8.1.8.4.1. Severity of Event

[0798] For adverse events (AEs) not included in the protocol defined grading system, the following guidelines will be used to describe severity.

[0799] • Mild - Events require minimal or no treatment and do not interfere with the participant's daily activities.

[0800] • Moderate - Events result in a low level of inconvenience or concern with the therapeutic measures. Moderate events may cause some interference with functioning.

[0801] • Severe - Events interrupt a participant's usual daily activity and may require systemic drug therapy or other treatment. Severe events are usually potentially life-threatening or incapacitating. Of note, the term "severe" does not necessarily equate to "serious".

[0802] 8.1.8.4.2. Relationship to Study Intervention All adverse events (AEs) must have their relationship to study intervention assessed by the clinician who examines and evaluates the participant based on temporal relationship and his / her clinical judgment. The degree of certainty about causality will be graded using the categories below. In a clinical trial, the study product must always be suspect.

[0803] • Related - The AE is known to occur with the study intervention, there is a reasonable possibility that the study intervention caused the AE, or there is a temporal relationship between the study intervention and event. Reasonable possibility means that there is evidence to suggest a causal relationship between the study intervention and the AE.

[0804] • Not Related - There is not a reasonable possibility that the administration of the study intervention caused the event, there is no temporal relationship between the study intervention and event onset, or an alternate etiology has been established.

[0805] OR

[0806] • Definitely Related - There is clear evidence to suggest a causal relationship, and other possible contributing factors can be ruled out. The clinical event, including an abnormal laboratory test result, occurs in a plausible time relationship to study intervention administration and cannot be explained by concurrent disease or other drugs or chemicals. The response to withdrawal of the study intervention (dechallenge) should be clinically plausible. The event must be pharmacologically or phenomenologically definitive, with use of a satisfactory rechallenge procedure if necessary.

[0807] • Probably Related - There is evidence to suggest a causal relationship, and the influence of other factors is unlikely. The clinical event, including an abnormal laboratory test result, occurs within a reasonable time after administration of the study intervention, is unlikely to be attributed to concurrent disease or other drugs or chemicals, and follows a clinically reasonable response on withdrawal (dechallenge). Rechallenge information is not required to fulfill this definition.

[0808] • Possibly Related - There is some evidence to suggest a causal relationship (e.g., the event occurred within a reasonable time after administration of the trial medication). However, other factors may have contributed to the event (e.g., the participant's clinical condition, other concomitant events). Although an AE may rate only as "possibly related" soon after discovery, it can be flagged as requiring more information and later be upgraded to "probably related" or "definitely related", as appropriate.

[0809] • Unlikely to be related - A clinical event, including an abnormal laboratory test result, whose temporal relationship to study intervention administration makes a causal relationship improbable (e.g., the event did not occur within a reasonable time after administration of the study intervention) and in which other drugs or chemicals or underlying disease provides plausible explanations (e.g., the participant's clinical condition, other concomitant treatments).

[0810] • Not Related - The AE is completely independent of study intervention administration, and / or evidence exists that the event is definitely related to another etiology. There must be an alternative, definitive etiology documented by the clinician.

[0811] 8.1.8.4.3. Expectedness

[0812] The Principal Investigator and / or treating sub-investigator will be responsible for determining whether an adverse event (AE) is expected or unexpected. An AE will be considered unexpected if the nature, severity, or frequency of the event is not consistent with the risk information previously described for the study intervention.

[0813] 8.1.8.5. Time Period and Frequency for Event Assessment and Follow-Up

[0814] The occurrence of an adverse event (AE) or serious adverse event (SAE) may come to the attention of study personnel during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor.

[0815] All AEs including local and systemic reactions not meeting the criteria for SAEs will be captured on the appropriate case report form (CRF). Information to be collected includes event description, time of onset, clinician's assessment of severity, relationship to study product (assessed only by those with the training and authority to make a diagnosis), and time of resolution / stabilization of the event. All AEs occurring while on study must be documented appropriately regardless of relationship. All AEs will be followed to adequate resolution.

[0816] Any medical condition that is present at the time that the participant is screened will be considered as baseline and not reported as an AE. However, if the study participant's condition deteriorates at any time during the study, it will be recorded as an AE.

[0817] Changes in the severity of an AE will be documented to allow an assessment of the duration of the event at each level of severity to be performed. AEs characterized as intermittent require documentation of onset and duration of each episode. The clinical research coordinator will record all reportable events with start dates occurring any time after informed consent is obtained until 30 days for non-serious AEs or 90 days (or 30 days following if the participant initiates new anticancer therapy) for SAEs after cessation of study treatment. At each study visit, the investigator will inquire about the occurrence of AE / SAEs since the last visit. Events will be followed for outcome information until resolution or stabilization.

[0818] 8.1.8.6. Adverse Event Reporting

[0819] AEs will be collected at the level of the subject, the date, the event, or the protocol. All AEs will be collected on an Adverse Event Form / Log and case report form. AEs and / or laboratory abnormalities must be documented. All non-serious AEs will be summarized and reported to the IRB at the time of IRB Continuing Review and to the FDA through an IND Annual Report sent to the FDA by the sponsor (Table 13).

[0820] Table 14: Time-Line for Reporting Events Based on Type of Adverse Event

[0821] 8.1.8.7. Serious Adverse Event Reporting

[0822] The study clinician will immediately report to the sponsor any serious adverse event, whether or not considered study intervention related, including those listed in the protocol or investigator brochure and must include an assessment of whether there is a reasonable possibility that the study intervention caused the event. Study endpoints that are serious adverse events (e.g., all-cause mortality) must be reported in accordance with the protocol unless there is evidence suggesting a causal relationship between the study intervention and the event (e.g., death from anaphylaxis). In that case, the investigator must immediately report the event to the sponsor.

[0823] All serious adverse events (SAEs) will be followed until satisfactory resolution or until the site investigator deems the event to be chronic or the participant is stable. Other supporting documentation of the event may be requested by the Data Coordinating Center (DCC) / study sponsor and should be provided as soon as possible.

[0824] Any SAE will be reported to the sponsor within 24 hours of knowledge of the event. The study sponsor will be informed within 2 working days of knowledge of the event. The study sponsor will be responsible for notifying the Food and Drug Administration (FDA) of any unexpected fatal or life-threatening suspected adverse reaction as soon as possible, but in no case later than 7 calendar days after the sponsor's initial receipt of the information. In addition, the sponsor must notify the FDA and all participating investigators in an Investigational New Drug (IND) safety report of potential serious risks, from clinical trials or any other source, as soon as possible, but no later than 15 calendar days after the sponsor determines that the information qualifies for reporting.

[0825] The time-line for reporting events is described in Table 13.

[0826] 8.1.8.8. Reporting Events to Participants

[0827] Participants will be informed of any adverse event that may change the risk-benefit of the study.

[0828] 8.1.8.9. Events of Special Interest

[0829] Selected non-serious and serious adverse events are also known as Events of Special Interest (ESI) and must be reported within 24 hours to the clinical trials office and Principal Investigator and within 2 working days to the study sponsor.

[0830] For the time period beginning when the consent form is signed until treatment allocation / randomization, any ESI, or follow up to an ESI, that occurs to any participant must be reported within 24 hours to the clinical trials office / Principal Investigator and within 2 working days to the study sponsor if it causes the participant to be excluded from the trial, or is the result of a protocol-specified intervention, including but not limited to: washout or discontinuation of usual therapy, diet, placebo treatment or a procedure.

[0831] For the time period beginning at treatment allocation / randomization through 90 days following cessation of treatment, or 30 days following cessation of treatment if the participant initiates new anticancer therapy, whichever is earlier, any ESI, or follow up to an SCI, whether or not related to dinutiximab beta, must be reported within 24 hours to the clinical trials office and Principal Investigator and 2 working days to the study funder, regardless of attribution to study treatment, consistent with standard SAE reporting guidelines.

[0832] Events of clinical interest for this trial include: • An overdose of dinutiximab beta (>2x dose) that is not associated with clinical symptoms or abnormal laboratory results.

[0833] 8.1.8.10. Reporting of Pregnancy

[0834] Although pregnancy and infant exposure during breast feeding are not considered adverse events, it is the responsibility of investigators or their designees to report any pregnancy or lactation in a participant (spontaneously reported to them) that occurs during the study.

[0835] Pregnancies and infant exposures during breastfeeding that occur after the consent form is signed but before treatment allocation must be reported by the investigator if they cause the participant to be excluded from the trial, or are the result of a protocol- specified intervention, including but not limited to washout or discontinuation of usual therapy, diet, placebo treatment or a procedure.

[0836] Pregnancies and infant exposures during breastfeeding that occur from the time of treatment allocation through 120 days following cessation of treatment, or 30 days following cessation of treatment if the participant initiates new anticancer therapy, whichever is earlier, must be reported by the investigator. All reported pregnancies must be followed to the completion / termination of the pregnancy. Pregnancy outcomes of spontaneous abortion, missed abortion, benign hydatidiform mole, blighted ovum, fetal death, intrauterine death, miscarriage and stillbirth must be reported as serious events (Important Medical Events). If the pregnancy continues to term, the outcome (health of infant) must also be reported.

[0837] Such events must be reported within 24 hours of knowledge of the event to the sponsor and within 2 working days of knowledge of the event to the study funder.

[0838] Unanticipated Problems

[0839] Definition of Unanticipated Problems (UP)

[0840] The Office for Human Research Protections (OHRP) considers unanticipated problems involving risks to participants or others to include, in general, any incident, experience, or outcome that meets all of the following criteria:

[0841] • Unexpected in terms of nature, severity, or frequency given (a) the research procedures that are described in the protocol-related documents, such as the Institutional Review Board (IRB)-approved research protocol and informed consent document; and (b) the characteristics of the participant population being studied; • Related or possibly related to participation in the research ("possibly related" means there is a reasonable possibility that the incident, experience, or outcome may have been caused by the procedures involved in the research); and

[0842] • Suggests that the research places participants or others at a greater risk of harm (including physical, psychological, economic, or social harm) than was previously known or recognized.

[0843] 8.1.9. Unanticipated Problem Reporting

[0844] The investigator will report unanticipated problems (UPs) to the reviewing Institutional Review Board (IRB) and to the Data Coordinating Center (DCC) / lead principal investigator (PI). The UP report will include the following information:

[0845] • Protocol identifying information: protocol title and number, Pi's name, and the IRB project number;

[0846] • A detailed description of the event, incident, experience, or outcome;

[0847] • An explanation of the basis for determining that the event, incident, experience, or outcome represents an UP;

[0848] • A description of any changes to the protocol or other corrective actions that have been taken or are proposed in response to the UP.

[0849] To satisfy the requirement for prompt reporting, UPs will be reported using the following timeline:

[0850] • All UPs will be reported to sponsor within 24 hours of the investigator becoming aware of the problem and within 2 working days to the study funder.

[0851] • For fatal / life threatening UPs, the PI should notify the IRB Chair by phone immediately and consider voluntarily halting subject enrollment. All other UPs will be reported to the IRB within 10 working days of the investigator becoming aware of the problem.

[0852] 8.1.10. Reporting Unanticipated Problems to Participants

[0853] Not applicable

[0854] 9. Statistical considerations

[0855] 9.1. Statistical Hypotheses

[0856] Primary Endpoint: The primary endpoint is dose limiting toxicity (DLT) during the first 10 weeks in patients with relapsed or refractory neuroblastoma. The recommended SBRT dose for metastatic soft tissue and bone disease will be based on anatomic site and determined by DLT derived from clinical and laboratory observations from this period according to the National Cancer Institute Common Terminology for Adverse Events Criteria (NCI CTCAE v5.0) that is related to SBRT + dinutuximab beta at 10 weeks (early toxicity) and after 10 weeks (late toxicity).

[0857] Hypothesis: Anatomic based doses of SBRT radiation combined with dinutuximab beta will be safe.

[0858] Secondary Endpoints:

[0859] 1. ORR at 10 weeks and best overall response determined by the 2017 International Neuroblastoma Response Criteria.1Objective response will be defined in two ways: 1) complete response (CR) + partial response (PR) and 2) CR + PR + minor response (MR).

[0860] Hypothesis: Treatment with SBRT combined with dinutuximab beta will have antitumor activity.

[0861] 2. Time-to-progression of disease outside radiated fields is defined as time from the date of study enrollment to the first occurrence of objective disease progression regions outside radiated fields or date of death due to any cause, whichever occurs first. Time- to-overall progression is defined as time from the date of study enrollment to the first occurrence of objective disease progression at any site or date of death due to any cause, whichever occurs first

[0862] Hypothesis: Time-to-progression of disease outside the radiation fields will be higher than historical controls.

[0863] 9.2. Sample Size Determination

[0864] The number of evaluable patients that will be needed for this phase I study depends on the number of metastatic locations for each patient entered and whether or not the dose is de-escalated for a given metastatic location. If each evaluable patient has lesions limited to a single metastatic location and therefore contributes only to the determination of the recommended SBRT dose for that metastatic location, then 15 evaluable patients will be needed to assess the initial starting dose.

[0865] If each metastatic location requires an evaluation at the de-escalated dose, 15 additional evaluable patients would be required across the 5 metastatic locations (as described in 6.1.1.1, Dose Fractionation). It is projected that most, if not all, evaluable patients will contribute to more than one metastatic location and that the number of evaluable patients required across the 5 metastatic locations will be in the range of 10- 15. It is projected that no more than 1 patient per dose level per metastatic location will be found to be ineligible or not start protocol treatment.

[0866] 9.3. Populations for Analyses

[0867] Evaluable patients will be defined as any eligible patient who begins protocol SBRT treatment for a given metastatic location. Individual patients may contribute to evaluation of multiple organ sites. For example, if a patient has liver and lymph node metastases, evaluation of toxicities in each of these sites (in addition to "Other") would occur.

[0868] 9.4. Statistical Analyses

[0869] 9.4.1. General Approach

[0870] For each of the 5 metastatic locations (as described in 6.1.1.1, Dose Fractionation), after 3 evaluable patients have been followed for a minimum of 10 weeks from the start of dinutuximab beta, the number of patients with DLT will be assessed. If there are 0 patients with a DLT, the initial starting dose level will be judged to be acceptable and determined to be the recommended SBRT dose for that metastatic location. If there is 1 patient with a DLT, an additional 3 patients will be enrolled. For each metastatic location, if there are 2 or more patients with DLTs at the initial starting dose level, then the dose will be de-escalated at that site. If this occurs, then 3 evaluable patients will be treated at the lower dose level and followed for a minimum of 10 weeks. If there are 0 patients with a DLT, the de-escalated dose will be declared to be the recommended SBRT dose for that metastatic location. If there is 1 patient with a DLT, an additional 3 patients will be enrolled. If there are 2 or more patients with a DLT at the de-escalated dose level, then there will be no recommended dose for that metastatic location. If at any time a Grade 5 treatment-related adverse event is observed or, as noted above, 2 or more DLTs in the "Other" category occur, the study will be placed on hold and the PI will review the data. All patients will be followed for long-term toxicity for a maximum of 2 years.

[0871] After the required number of evaluable patients have been accrued for a given dose level, the accrual for that metastatic location will be temporarily suspended while the safety of that dose level is assessed (i.e., until all patients have completed 10 weeks of follow-up). Newly enrolled patients will receive radiation to their respective sites at the dose level deemed safe at the time of enrollment. If at any time the cumulative toxicity rate equals or exceeds 33% at a particular site, the study will be placed on hold and PI will review the data.

[0872] 9.4.2. Analysis of the Primary Endpoint(s)

[0873] Treatment related DLT during the first 10 weeks of treatment with SBRT + dinutuximab beta (early toxicity) in patients with relapsed or refractory neuroblastoma. The recommended SBRT dose for metastatic soft tissue and bone disease will be based on anatomic site and determined by DLT derived from clinical and laboratory observations from this period according to the National Cancer Institute Common Terminology for Adverse Events Criteria (NCI CTCAE v5.0).

[0874] Exact logistic regression analyses will be conducted to model the probability of DLT as a function of site dose, number of metastatic sites, and cumulative body radiation. The frequencies of AEs by type, body system, severity and relationship to study drug will be summarized. SAEs (if any) will be described in detail. AE incidence will be summarized along with the corresponding 95% confidence intervals. Laboratory values will be summarized with descriptive statistics, including quartiles and range for each laboratory value of interest. If these analyses suggest a high (>=33%) probability of toxicity for a particular combination of predictors, dose recommendations may be modified. Similar analyses will be conducted on a per patient basis to model the probability of DLT at any site as a function of cumulative dose and number of sites involved

[0875] 9.4.3. Analysis of the Secondary Endpoint(s)

[0876] ORR at 10 weeks and best overall response will defined using the 2017 INRC. Response will also be described as overall response rate (including radiated and non-radiated lesions) as well as response rate of non-radiated lesions (patient level response excluding radiated lesions).

[0877] Progression-free survival will be estimated using the Kaplan-Meier method. Time-to- progression of disease outside radiated fields as well as overall time-to-progression will be evaluated.

[0878] 9.4.4. Baseline Descriptive Statistics

[0879] Baseline and demographic characteristics will be summarized by standard descriptive summaries (e.g. means / medians and standard deviations for continuous variables and percentages for categorical variables). 9.4.5. Planned Interim Analyses

[0880] Not applicable

[0881] 9.4.6. Sub-Group Analyses

[0882] Toxicity and responses will be summarized by metastatic sites of disease as well as by age.

[0883] 9.4.7. Tabulation of Individual participant Data

[0884] Individual participant data will not be listed by measure and time point.

[0885] 9.4.8. Exploratory Analyses

[0886] To explore the immunological effects of the combination of SBRT and anti-GD2 therapy with dinutuximab beta by assessing a defined T cell-inflamed gene expression signature and other molecular markers in tumor samples.

[0887] To explore potential microbiome and epigenetic cell-free DNA biomarkers associated with response to treatment with combination of stereotactic body radiotherapy (SBRT) and dinutuximab beta.

[0888] Example 2: A supplemental study design based upon the Phase 1 study of dinutuximab beta with stereotactic body radiotherapy (SBRT) for the treatment of metastasis in relapsed or refractory neuroblastoma in children, adolescents, and young adults disclosed in Example 1.

[0889] The following description notes changes compared to the design in Example 1.

[0890] 1.1. Study Synopsis

[0891] The Study Synopsis corresponds to section 1.1 of Example 1, with the following differences:

[0892] • Metagenomic sequencing of the gut microbiome will be carried on stool samples.

[0893] • Exploratory objectives include:

[0894] Explorative objectives:

[0895] 1. To evaluate the tumor immune signature from pre-therapy samples and assess its correlation with response to SBRT and dinutuximab beta.

[0896] 2. To describe the change in immune effector cells and cytokines before and after SBRT as well as longitudinally while receiving dinutuximab beta.

[0897] 3. To explore potential microbiome signatures and 5hmc profiles in cfDNA associated with response to treatment with SBRT and dinutuximab beta.

[0898] Primary endpoints:

[0899] References to Dose limiting toxicity (DLT) with respect to the primary endpoint relates to the definition outlined in the National Cancer Institute Common Terminology for Adverse Events Criteria (NCI CTCAE v5.0) that is related to treatment.

[0900] Description of Study Intervention:

[0901] Participants will undergo SBRT to 1-3 eligible metastatic lesions over the course of 1 week (Monday-Friday). Blood and stool specimens will be collected prior to and after radiation, as well as during the course of therapy.

[0902] An updated schedule of activities can be found in appendix 6. 2. INTRODUCTION

[0903] 2.1. Study rationale

[0904] The Study rationale corresponds to section 2.1 of Example 1, with the exception that the tumour microenvironment will not be assessed during exploratory studies.

[0905] 2.2. Background

[0906] 2.2.1. Rationale for research design and population

[0907] Subsections 2.2.1.1-2.2.1.4 correspond to subsections 2.2.1.1-2.2.1.4 of Example 1 in their entirety.

[0908] 2.2.2. Dinutuximab beta

[0909] Subsection 2.2.2 correspond to subsection 2.2.2 of Example 1 in its entirety.

[0910] 2.2.3. Stereotactic body radiotherapy and dinutuximab beta: dose rationale

[0911] Subsection 2.2.3 corresponds to subsection 2.2.3 of Example 1, with the following difference:

[0912] • Radiotherapy will be administered to one or more of the following sites categorized as: 1) mediastinal / thoracic (axillary or cervical) lymph node, 2) spinal / paraspinal / osseous, or 3) abdominal-pelvic metastases (e.g. lymph node).

[0913] 2.2.4. Rationale for correlative biology studies

[0914] Subsection 2.2.4 correspond to subsection 2.2.4 of Example 1, with the following differences:

[0915] Tumour tissue includes archival tissue or tissue from a clinical biopsy at the time of relapse.

[0916] 2.3. Assessment of potential risks and benefits

[0917] Subsection 2.3 correspond to subsection 2.3 of Example 1 in its entirety.

[0918] 3. STUDY OBJECTIVES AND ENDPOINTS

[0919] Subsections 3.1-3.3 correspond to subsections 3.1-3.3 of Example 1, with the following differences:

[0920] Tertiary / exploratory objectives and endpoints

[0921] Objectives: 1. To evaluate the tumor immune signature from pre-therapy samples and assess its correlation with response to SBRT and dinutuximab beta.

[0922] 2. To describe the change in immune effector cells and cytokines before and after SBRT as well as longitudinally while receiving dinutuximab beta.

[0923] 3. To explore potential microbiome signatures and 5hmc profiles in cfDNA associated with response to treatment with SBRT and dinutuximab beta.

[0924] Endpoints:

[0925] 1. Immune signature determined by analysis of RNA seq data from tumor samples

[0926] 2. Longitudinal immunophenotyping and measurement of cytokines (e.g.IFN-y) in peripheral blood pre-post SBRT

[0927] 3. Correlate longitudinal measurement of alpha and beta diversity and microbial species (gut microbiome) and 5hmc profiles with disease burden and response.

[0928] Justification for endpoints:

[0929] 1. Previous analyses have demonstrated that a t-cell inflamed signature is correlated with improved survival for patients with high-risk neuroblastoma.

[0930] 2. The exploratory correlative biology studies may provide insight into changes in the immune repertoire before and after radiation as well as during anti-GD2 therapy and how this may be associated with response to therapy.

[0931] 3. Evaluation of potential of stool microbiome signatures and epigenetic profiles as biomarkers.

[0932] 4. STUDY OBJECTIVES AND ENDPOINTS

[0933] 4.1. Overall design

[0934] Subsection 4.1 corresponds to subsection 4.1 of Example 1, with the following differences:

[0935] • The study will also provide the opportunity to explore changes in the immune effector cells and cytokines induced by SBRT through peripheral Immunophenotyping and cytokine analysis. The tumour microenvironment may not be subject to investigation.

[0936] • In week 1, treatment will include radiation of 1-3 metastatic lesions in different sites via SBRT.

[0937] • Blood and stool specimens will be collected prior to and after radiation and during the course of therapy.

[0938] Further details concerning "Scientific Rationale for Study design", "Justification for dose" and "End of study definition" can be found in subsections 4.2-4.4 of Example 1. 5. STUDY POPULATION

[0939] 5.1. Inclusion criteria

[0940] Subsection 5.1 corresponds to subsection 5.1 of Example 1, with the following differences:

[0941] Site of Disease and Disease status

[0942] At least one tumor lesion must meet the at least one of following criteria for SBRT radiation:

[0943] • 0.25 cc to 65 cc of viable tumor (i.e. primary disease or metastases) approximately 5 cm in maximal dimension. Tumors larger than 65 cc can be partially treated if needed.

[0944] • Metastases located in mediastinal / cervical nodes, spinal / paraspinal / osseous, or abdominal-pelvic (lymph node / adrenal gland).

[0945] Organ Function Requirements

[0946] Hematologic Function: Patients must meet the following hematologic criteria for enrollment regardless of bone marrow disease involvement.

[0947] ANC > 500 / uL (no short-acting hematopoietic growth factors within 7 days of blood draw documenting eligibility and no long-acting hematopoietic growth factors within 14 days of blood draw documenting eligibility); and

[0948] Platelet count > 25,000 / pl, transfusion independent (no platelet transfusions or platelet growth factors within 7 days of blood draw documenting eligibility).

[0949] 5.2. Exclusion criteria

[0950] Subsection 5.2 corresponds to subsection 5.2 of Example 1 in its entirety.

[0951] Further details concerning "Lifestyle considerations" and "Screen failures" can be found in subsections 5.3-5.4 of Example 1.

[0952] 6. STUDY INTERVENTIONS

[0953] Section 6 corresponds to section 6 of Example 1, with the following differences:

[0954] • Anatomic sites of metastatic disease will no longer include the lung or liver.

[0955] • Mediastinal / Cervical Lymph Nodes may no longer be subject to additional studies involving MRI.

[0956] • Hematologic parameters to begin each cycle of dinutuximab beta includes: o ANC > 500 / jiL o Platelet count > 25,000 / .L (transfusion independent for > 7 days).

[0957] Hematologic DLTs will be assessed in relation to treatment related myelosuppression. 7. STUDY INTERVENTION DISCONTINUATION AND PARTICIPANT

[0958] DISCO N TI N UATIO N / WIT H D RAWAL

[0959] Section 7 corresponds to section 7 of Example 1 in its entirety.

[0960] 8. STUDY ASSESSMENTS AND PROCEDURES

[0961] Section 8 corresponds to section 8 of Example 1 with the following differences: The following table outline the requirements for tissue, blood, and stool banking. These will be collected and stored for batched future analysis:

[0962] Table 14: Correlative Biology samples

[0963]

[0964] 9. STATISTICAL CONSIDERATIONS

[0965] Section 9 corresponds to section 9 of Example 1 with the following differences:

[0966] In accordance with the sections above, the number of metastatic locations has been reduced to 3. Consequently, it is projected that most, if not all, evaluable patients will contribute to more than one metastatic location and that the number of evaluable patients required across the 3 metastatic locations will be in the range of 12-18.

[0967] • If there are 0 patients with a DLT, three additional patients will be enrolled and if < = 1 of 6 DLTs occur, the initial starting dose level will be judged to be acceptable and determined to be the recommended SBRT dose for that metastatic location.

[0968] • If there is 1 patient with a DLT, an additional 3 patients will be enrolled and the dose recommended if no additional DLTs are observed.

[0969] • For hematologic DLTs in patients who received radiation to more than one anatomic site, the investigator will determine if a particular site is associated with the DLT.

[0970] Analysis of secondary endpoints will include the generation of exact binomial 95% confidence intervals. In accordance with the explorative objectives, the immunological effects of the combination of SBRT and anti-GD2 therapy with dinutuximab beta will be explored by assessing immune effector cells and cytokines. Changes pre-post SBRT will be analyzed using paired t-tests or nonparametric Wilcoxon signed rank tests. Longitudinal immunophenotyping results during anti-GD2 therapy will be described.

[0971] Logistic regression models will be fit to explore the association between potential microbiome and epigenetic cell-free DNA biomarkers and response to treatment with combination of stereotactic body radiotherapy (SBRT) and dinutuximab beta.

[0972] ABBREVIATIONS

[0973] AE Adverse Event

[0974] CFR Code of Federal Regulations

[0975] CLIA Clinical Laboratory Improvement Amendments

[0976] CMP Clinical Monitoring Plan

[0977] COC Certificate of Confidentiality

[0978] CONSORT Consolidated Standards of Reporting Trials

[0979] CR Complete Response

[0980] CRF Case Report Form

[0981] DCC Data Coordinating Center

[0982] DLT Dose Limiting Toxicity

[0983] DHHS Department of Health and Human Services

[0984] DSMB Data Safety Monitoring Board eCRF Electronic Case Report Forms

[0985] ESI Event of special interest

[0986] FDA Food and Drug Administration

[0987] GCP Good Clinical Practice

[0988] GMP Good Manufacturing Practices

[0989] GWAS Genome-Wide Association Studies

[0990] HIPAA Health Insurance Portability and Accountability Act

[0991] IB Investigator's Brochure

[0992] ICH International Conference on Harmonisation

[0993] ICMJE International Committee of Medical Journal Editors

[0994] IND Investigational New Drug Application

[0995] INRC International Neuroblastoma Response Criteria

[0996] IRB Institutional Review Board ISO International Organization for Standardization

[0997] MD Minimal Disease

[0998] MIBG Meta-iodobenzylguanidine

[0999] MOP Manual of Procedures

[1000] MR Minor response

[1001] NIH National Institutes of Health

[1002] NR No Response

[1003] OHRP Office for Human Research Protections

[1004] ORR Objective Response Rate

[1005] PI Principal Investigator

[1006] PR Partial Response

[1007] QA Quality Assurance

[1008] QC Quality Control

[1009] SAE Serious Adverse Event

[1010] SAP Statistical Analysis Plan

[1011] SBRT Stereotactic Body Radiotherapy

[1012] SD Stable Disease

[1013] SOA Schedule of Activities

[1014] UP Unanticipated Problem

[1015] US United States

[1016] REFERENCES

[1017] 1. Park JR, Bagatell R, Cohn SL, et al. Revisions to the International Neuroblastoma Response Criteria: A Consensus Statement From the National Cancer Institute Clinical Trials Planning Meeting. J Clin Oncol. 2017;35: 2580-2587.

[1018] 2. Matthay KK, Maris JM, Schleiermacher G, et al. Neuroblastoma. Nat Rev Dis Primers. 2016;2: 16078.

[1019] 3. Park JR, Eggert A, Caron H. Neuroblastoma: biology, prognosis, and treatment. Hematol Oncol Clin North Am. 2010;24: 65-86.

[1020] 4. Pinto NR, Applebaum MA, Volchenboum SL, et al. Advances in Risk Classification and Treatment Strategies for Neuroblastoma. J Clin Oncol. 2015;33: 3008-3017.

[1021] 5. Maris JM. Recent advances in neuroblastoma. N Engl J Med. 2010;362: 2202-2211.

[1022] 6. London WB, Bagatell R, Weigel BJ, et aL Historical time to disease progression and progression-free survival in patients with recurrent / refractory neuroblastoma treated in the modern era on Children's Oncology Group early-phase trials. Cancer. 2017; 123: 4914-4923.

[1023] 7. Pinto N, Naranjo A, Hibbitts E, et al. Predictors of differential response to induction therapy in high-risk neuroblastoma: A report from the Children's Oncology Group (COG). Eur J Cancer. 2019; 112: 66-79.

[1024] 8. Lee Y, Auh SL, Wang Y, et aL Therapeutic effects of ablative radiation on local tumor require CD8+ T cells: changing strategies for cancer treatment. Blood. 2009; 114: 589- 595.

[1025] 9. Liang H, Deng L, Chmura S, et al. Radiation-induced equilibrium is a balance between tumor cell proliferation and T cell-mediated killing. J Immunol. 2013; 190: 5874-5881.

[1026] 10. Geoerger B, Kang HJ, Yalon-Oren M, et aL Pembrolizumab in paediatric patients with advanced melanoma or a PD-Ll-positive, advanced, relapsed, or refractory solid tumour or lymphoma (KEYNOTE-051): interim analysis of an open-label, single-arm, phase 1-2 trial. Lancet OncoL 2020;21: 121-133.

[1027] 11. Yu AL, Gilman AL, Ozkaynak MF, et aL Anti-GD2 antibody with GM-CSF, interleukin- 2, and isotretinoin for neuroblastoma. N Engl J Med. 2010;363: 1324-1334.

[1028] 12. Yu AL, Gilman AL, Ozkaynak MF, et aL Long-Term Follow-up of a Phase III Study of chl4.18 (Dinutuximab) + Cytokine Immunotherapy in Children with High-Risk Neuroblastoma: COG Study ANBL0032. Clin Cancer Res. 2021;27: 2179-2189.

[1029] 13. Mody R, Naranjo A, Van Ryn C, et al. Irinotecan-temozolomide with temsirolimus or dinutuximab in children with refractory or relapsed neuroblastoma (COG ANBL1221): an open-label, randomised, phase 2 trial. Lancet OncoL 2017; 18: 946- 957. 14. Mody R, Yu AL, Naranjo A, et al. Irinotecan, Temozolomide, and Dinutuximab With GM-CSF in Children With Refractory or Relapsed Neuroblastoma: A Report From the Children's Oncology Group. J Clin Oncol. 2020;38: 2160-2169.

[1030] 15. Ladenstein R, Potschger U, Valteau-Couanet D, et al. Investigation of the Role of Dinutuximab Beta-Based Immunotherapy in the SIOPEN High-Risk Neuroblastoma 1 Trial (HR-NBL1). Cancers (Basel). 2020; 12.

[1031] 16. Lawrence MS, Stojanov P, Polak P, et aL Mutational heterogeneity in cancer and the search for new cancer-associated genes. Nature. 2013;499: 214-218.

[1032] 17. Park JA, Cheung NV. Limitations and opportunities for immune checkpoint inhibitors in pediatric malignancies. Cancer Treat Rev. 2017;58: 22-33.

[1033] 18. Durante M, Reppingen N, Held KD. Immunologically augmented cancer treatment using modern radiotherapy. Trends Mol Med. 2013; 19: 565-582.

[1034] 19. Gaipl US, Multhoff G, Scheithauer H, et aL Kill and spread the word: stimulation of antitumor immune responses in the context of radiotherapy. Immunotherapy. 2014;6: 597-610.

[1035] 20. Demaria S, Formenti SC. Radiation as an immunological adjuvant: current evidence on dose and fractionation. Front Oncol. 2012;2: 153.

[1036] 21. Deng L, Liang H, Burnette B, et al. Irradiation and anti-PD-Ll treatment synergistically promote antitumor immunity in mice. J Clin Invest. 2014; 124: 687-695.

[1037] 22. Postow MA, Callahan MK, Barker CA, et aL Immunologic correlates of the abscopal effect in a patient with melanoma. N Engl J Med. 2012;366: 925-931.

[1038] 23. Milano MT, Katz AW, Zhang H, Okunieff P. Oligometastases treated with stereotactic body radiotherapy: long-term follow-up of prospective study. Int J Radiat Oncol Biol Phys. 2012;83: 878-886.

[1039] 24. Iyengar P, Kavanagh BD, Wardak Z, et aL Phase II trial of stereotactic body radiation therapy combined with erlotinib for patients with limited but progressive metastatic non-small-cell lung cancer. J Clin Oncol. 2014;32: 3824-3830.

[1040] 25. Joseph RW, Elassaiss-Schaap J, Wolchok JD, et aL Baseline tumor size as an independent prognostic factor for overall survival in patients with metastatic melanoma treated with the anti-PD-1 monoclonal antibody MK-3475. Journal of Clinical Oncology. 2014;32: 3015-3015.

[1041] 26. Luke JJ, Lemons JM, Karrison TG, et aL Safety and Clinical Activity of Pembrolizumab and Multisite Stereotactic Body Radiotherapy in Patients With Advanced Solid Tumors. J Clin Oncol. 2018;36: 1611-1618.

[1042] 27. Luke JJ, Onderdonk BE, Bhave SR, et aL Improved Survival Associated with Local Tumor Response Following Multisite Radiotherapy and Pembrolizumab: Secondary Analysis of a Phase I Trial. Clin Cancer Res. 2020;26: 6437-6444. 28. Deng L, Liang H, Xu M, et al. STING-Dependent Cytosolic DNA Sensing Promotes Radiation-Induced Type I Interferon-Dependent Antitumor Immunity in Immunogenic Tumors. Immunity. 2014;41: 843-852.

[1043] 29. Liang H, Deng L, Hou Y, et al. Host STING-dependent MDSC mobilization drives extrinsic radiation resistance. Nat Commun. 2017;8: 1736.

[1044] 30. Phillips R, Shi WY, Deek M, et al. Outcomes of Observation vs Stereotactic Ablative Radiation for Oligometastatic Prostate Cancer: The ORIOLE Phase 2 Randomized Clinical Trial. JAMA Oncol. 2020;6: 650-659.

[1045] 31. Dinutuximab beta, Investigator's Brochure Version 3.0.

[1046] 32. Al-Hallaq HA, Chmura S, Salama JK, et aL Rationale of technical requirements for NRG-BR001: The first NCI-sponsored trial of SBRT for the treatment of multiple metastases. Pract Radiat OncoL 2016;6: e291-e298.

[1047] 33. Chmura SJ WK, Salama JK, et aL Phase I Trial of Stereotactic Body Radiation Therapy (SBRT) to Multiple Metastatic Sites: A NRG Oncology Study. International Journal of Radiation Oncology • Biology • Physics. 2018; 102: S68-S69.

[1048] 34. Chmura S, Winter KA, Robinson C, et al. Evaluation of Safety of Stereotactic Body Radiotherapy for the Treatment of Patients With Multiple Metastases: Findings From the NRG-BR001 Phase 1 Trial. JAMA OncoL 2021;7: 845-852.

[1049] 35. Foster CC, Fleming GF, Karrison TG, et al. Phase I Study of Stereotactic Body Radiotherapy plus Nivolumab and Urelumab or Cabiralizumab in Advanced Solid Tumors. Clin Cancer Res. 2021;27: 5510-5518.

[1050] 36. Ladenstein RL, Poetschger U, Valteau-Couanet D, et al. Randomization of dose- reduced subcutaneous interleukin-2 (scIL2) in maintenance immunotherapy (IT) with anti-GD2 antibody dinutuximab beta (DB) long-term infusion (LTI) in front-line high- risk neuroblastoma patients: Early results from the HR-NBL1 / SIOPEN trial. Journal of Clinical Oncology. 2019;37: 10013-10013.

[1051] 37. Ladenstein R, Potschger U, Valteau-Couanet D, et aL Interleukin 2 with anti-GD2 antibody chl4.18 / CHO (dinutuximab beta) in patients with high-risk neuroblastoma (HR-NBL1 / SIOPEN): a multicentre, randomised, phase 3 trial. Lancet OncoL 2018; 19: 1617-1629.

[1052] 38. Lode HN, Valteau-Couanet D, Garaventa A, et aL Long-term infusion of anti-GD2 antibody chl4.18 / CHO in combination with interleukin-2 (IL2) activity and efficacy in high-risk relapsed / refractory neuroblastoma patients. Journal of Clinical Oncology. 2015;33: TPS10080-TPS10080.

[1053] 39. Mueller I, Ehlert K, Endres S, et aL Tolerability, response and outcome of high-risk neuroblastoma patients treated with long-term infusion of anti-GD2 antibody chl4.18 / CHO. MAbs. 2018; 10: 55-61. 40. Troschke-Meurer S, Siebert N, Marx M, et al. Low CD4(+) / CD25(+) / CD127(-) regulatory T cell- and high INF-gamma levels are associated with improved survival of neuroblastoma patients treated with long-term infusion of chl4.18 / CHO combined with interleukin-2. Oncoimmunology. 2019;8: 1661194.

[1054] 41. Spranger S, Spaapen RM, Zha Y, et al. Up-Regulation of PD-L1, IDO, and Tregs in the Melanoma Tumor Microenvironment Is Driven by CD8+ T Cells. Sci Transl Med. 2013;5: 200rall6.

[1055] 42. Gajewski TF, Louahed J, Brichard VG. Gene signature in melanoma associated with clinical activity: a potential clue to unlock cancer immunotherapy. Cancer J. 2010; 16: 399-403.

[1056] 43. Gajewski TF, Schreiber H, Fu YX. Innate and adaptive immune cells in the tumor microenvironment. Nat Immunol. 2013; 14: 1014-1022.

[1057] 44. Gajewski TF, Woo SR, Zha Y, et al. Cancer immunotherapy strategies based on overcoming barriers within the tumor microenvironment. Curr Opin Immunol. 2013;25: 268-276.

[1058] 45. Harlin H, Meng Y, Peterson AC, et al. Chemokine expression in melanoma metastases associated with CD8+ T-cell recruitment. Cancer Res. 2009;69: 3077- 3085.

[1059] 46. Ji RR, Chasalow SD, Wang L, et al. An immune-active tumor microenvironment favors clinical response to ipilimumab. Cancer Immunol Immunother. 2011.

[1060] 47. Topalian SL, Hodi FS, Brahmer JR, et al. Safety, Activity, and Immune Correlates of Anti-PD-1 Antibody in Cancer. N Engl J Med. 2012.

[1061] 48. Deng L, Liang H, Burnette B, et al. Irradiation and anti-PD-Ll treatment synergistically promote antitumor immunity in mice. J Clin Invest.124: 687-695.

[1062] 49. Kalbasi A, June CH, Haas N, Vapiwala N. Radiation and immunotherapy: a synergistic combination. J Clin Invest. 2013; 123: 2756-2763.

[1063] 50. Bao R, Spranger S, Hernandez K, et al. Immunogenomic determinants of tumor microenvironment correlate with superior survival in high-risk neuroblastoma. J Immunother Cancer. 2021;9.

[1064] 51. Goldszmid RS, Dzutsev A, Trinchieri G. Host immune response to infection and cancer: unexpected commonalities. Cell Host Microbe. 2014; 15: 295-305.

[1065] 52. Zitvogel L, Galluzzi L, Viaud S, et al. Cancer and the gut microbiota: an unexpected link. Sci Transl Med. 2015;7: 271ps271.

[1066] 53. Goldszmid RS, Dzutsev A, Viaud S, Zitvogel L, Restifo NP, Trinchieri G. Microbiota Modulation of Myeloid Cells in Cancer Therapy. Cancer Immunol Res. 2015;3: 103- 109.

[1067] 54. Matson V, Fessler J, Bao R, et aL The commensal microbiome is associated with anti-PD-1 efficacy in metastatic melanoma patients. Science. 2018; 359: 104-108. 55. Gopalakrishnan V, Spencer CN, Nezi L, et al. Gut microbiome modulates response to anti-PD-1 immunotherapy in melanoma patients. Science. 2018;359: 97-103.

[1068] 56. Routy B, Le Chatelier E, Derosa L, et al. Gut microbiome influences efficacy of PD- 1-based immunotherapy against epithelial tumors. Science. 2018;359: 91-97.

[1069] 57. Chaput N, Lepage P, Coutzac C, et al. Baseline gut microbiota predicts clinical response and colitis in metastatic melanoma patients treated with ipilimumab. Ann Oncol. 2017;28: 1368-1379.

[1070] 58. Frankel AE, Coughlin LA, Kim J, et al. Metagenomic Shotgun Sequencing and Unbiased Metabolomic Profiling Identify Specific Human Gut Microbiota and Metabolites Associated with Immune Checkpoint Therapy Efficacy in Melanoma Patients. Neoplasia. 2017; 19: 848-855.

[1071] 59. Applebaum MA, Barr EK, Karpus J, et al. 5-Hydroxymethylcytosine Profiles Are Prognostic of Outcome in Neuroblastoma and Reveal Transcriptional Networks That Correlate With Tumor Phenotype. JCO Precis Oncol. 2019;3.

[1072] 60. Applebaum MA, Barr EK, Karpus J, et al. 5-Hydroxymethylcytosine Profiles in Circulating Cell-Free DNA Associate with Disease Burden in Children with Neuroblastoma. Clin Cancer Res. 2020;26: 1309-1317.

[1073] 61. Salama JK, Hasselle MD, Chmura SJ, et al. Stereotactic body radiotherapy for multisite extracranial oligometastases: final report of a dose escalation trial in patients with 1 to 5 sites of metastatic disease. Cancer. 2012; 118: 2962-2970.

[1074] 62. Irwin MS, Naranjo A, Zhang FF, et al. Revised Neuroblastoma Risk Classification System: A Report From the Children's Oncology Group. J Clin Oncol. 2021;39: 3229- 3241.

[1075] 63. Schwartz GJ, Gauthier B. A simple estimate of glomerular filtration rate in adolescent boys. J Pediatr. 1985; 106: 522-526.

[1076] 64. Wolden SL, Barker CA, Kushner BH, et al. Brain-sparing radiotherapy for neuroblastoma skull metastases. Pediatr Blood Cancer. 2008;50: 1163-1168.

[1077] 65. Rao AD, Ladra M, Dunn E, et al. A Road Map for Important Centers of Growth in the Pediatric Skeleton to Consider During Radiation Therapy and Associated Clinical Correlates of Radiation-Induced Growth Toxicity. Int J Radiat Oncol Biol Phys. 2019; 103: 669-679.

[1078] 66. Kushner BH. Neuroblastoma: a disease requiring a multitude of imaging studies. J Nucl Med. 2004;45: 1172-1188.

[1079] 67. Treves ST, Gelfand MJ, Fahey FH, Parisi MT. 2016 Update of the North American Consensus Guidelines for Pediatric Administered Radiopharmaceutical Activities. J Nucl Med. 2016;57: 15N-18N. 68. Bagatell R, McHugh K, Naranjo A, et al. Assessment of Primary Site Response in Children With High-Risk Neuroblastoma: An International Multicenter Study. J Clin Oncol. 2016;34: 740-746.

[1080] 69. Burchill SA, Beiske K, Shimada H, et al. Recommendations for the standardization of bone marrow disease assessment and reporting in children with neuroblastoma on behalf of the International Neuroblastoma Response Criteria Bone Marrow Working Group. Cancer. 2017; 123: 1095-1105.

[1081] 70. Cerami, E. AACR Project GENIE: Powering Precision Medicine through an International Consortium. Cancer Discov. 2017 Aug; 7(8): 818-831.

[1082] 71. Smith, V; Foster, F. High-Risk Neuroblastoma Treatment Review. Children (Basel). 2018 Sep; 5(9): 114.

[1083] 72. Kalinovsky, D.V et al. Minibody-Based and scFv-Based Antibody Fragment-Drug Conjugates Selectively Eliminate GD2-Positive Tumor Cells. Int J Mol Sci. 2023 Jan; 24(2): 1239.

[1084] 73. Markham, A. Naxitamab: First Approval. Drugs

[1085] 74. Shevedian, N et al. Previous radiotherapy and the clinical activity and toxicity of pembrolizumab in the treatment of non-small-cell lung cancer: a secondary analysis of the KEYNOTE-001 phase 1 trial. Lancet Oncol. 2017 Jul; 18(7):895-903.

[1086] 75. Monclair, T, et al. The International Neuroblastoma Risk Group (INRG) staging system: an INRG Task Force report. J Clin Oncol. 2009 Jan 10;27(2):298-303

[1087] 76. Sterner, E et al. Therapeutic Antibodies to Ganglioside GD2 Evolved from Highly Selective Germline Antibodies. Cell Rep. 2017 Aug 15;20(7): 1681-1691

[1088] 77. Zola, H. "Monoclonal Antibodies; A manual of techniques. CRC Press. 1988.

[1089] 78. Hurrell, SGR

[1090] 79. Lee, H et al. Complete humanization of the mouse immunoglobulin loci enables efficient therapeutic antibody discovery. Nat Biotechnol. 2014. 32, 356-363.

[1091] 80. Neuberger et al (1998, 8th International Biotechnology Symposium Part 2, 792- 799)

[1092] Appendix 1: Age-specific performance scales Appendix 2: Laboratory tests

[1093] Appendix 3 : Curie scoring worksheet

[1094] Study Number: Radiology reviewer: Date of scan: Type of Scan (check 1): 1-123 M I BG [ ] 1-131 MIBG [ ]

[1095] (DD / MM / YYYY)

[1096] Scan time point (circle 1 ): Baseline After Cycle Relapse / Progression

[1097] Other (specify):

[1098] Table 1a. Scoring skeletal Table 1b. Scoring soft tissue disease disease Appendix 4: Overall response criteria Appendix 5

[1099] Appendix 5

[1100] Appendix 5

[1101] a-Screening: up to 21 days. Tumor evaluations (imaging and bilateral bone marrow aspirates and biopsies), echocardiogram, electrocardiogram must occur with 21 days to allocation / enrollment. Laboratory assessments / procedures must occur within 7 days to allocation / enrollment. b- Scheduling window (Days) for radiation treatment signifies that radiation must be completed within a 14 day window but is separate

[1102] 5 from the screening phase. Treatment with dinutuximab beta must start within 1 week of final SBRT dose (ideally 3 days after final SBRT dose) and will constitute protocol "Day 1". c- Treatment cycles: Treatment with dinutuximab beta must start within 1 week of final SBRT dose (ideally 3 days after final SBRT dose) and will constitute protocol "Day 1"; dinutuximab beta will be administered every 5 weeks (35 days) + / - 3 days. Laboratory assessments can be completed up to 72 hours before the scheduled visit.

[1103] 10 d- Echocardiogram and electrocardiogram (12-lead ECG) should be performed at the Screening visit only. Electrocardiogram (6-lead-ECG) is acceptable in accordance with local standard of care e- Pregnancy test: For females of childbearing potential: At minimum, will be completed during Screening, within 72 hours of beginning SBRT, and within 72 hours of Day 1 of each cycle of dinutuximab beta f- Tumor imaging: Imaging studies will include cross sectional imaging (CT or MRI) and 123I-MIBG scintigraphy. Participants with MIBG

[1104] 15 non-avid disease will undergo 18FDG-PET Scintigraphy instead of 123I-MIBG scintigraphy. [Brain imaging, if performed to document the stability of existing metastases at Screening, should be done by MRI if possible. If MRI is medically contraindicated, CT with contrast is an acceptable alternative. For participants without a history of brain metastases, head imaging is not required]. Imaging can be completed between days 22-28 for administrative reasons or scheduling. g- Bilateral bone marrow aspirates and biopsies: Completed per institutional standards.

[1105] 20 h- Obtain archival tumor tissue if available. Biopsies are optional. Obtain tumor tissue if a procedure is completed for clinical purposes.

[1106] i- Correlative studies blood collection (See Section 8.1.6.1 for volume of blood and additional details) j- Pre-treatment on Day 1 of every other odd cycle beginning with Cycle 3 (e.g. cycle 3, 5, 7, etc.) k- Collect if evidence of disease progression

[1107] I- Follow up visits for participants who discontinue therapy without progressive disease every 8 weeks + / - 7 days; after 1 year, visits and

[1108] 5 imaging can every 12 weeks + / - 7 days. Every effort should be made to collect information regarding disease status until the start of new anti-cancer therapy, disease progression, death, or end of the study m- Survival follow up entails telephone calls to assess survival status every 12 weeks until death, withdrawal of consent, or the end of the trial, whichever occurs first.

[1109] Appendix 6

[1110] Appendix 6

[1111] Appendix 6 a-Screening: up to 21 days. Tumor evaluations (imaging and bilateral bone marrow aspirates and biopsies), echocardiogram, electrocardiogram must occur with 21 days to allocation / enrolment. Laboratory assessments / procedures must occur within 7 days to allocation / enrolment.

[1112] b- Scheduling window (Days) for radiation treatment signifies that radiation must be completed within a 14-day window but is separate from the screening phase. Treatment with dinutuximab beta must start within 1 week of final SBRT dose (ideally 3 days after final SBRT dose) and will constitute protocol "Day 1". c- Treatment cycles: Treatment with dinutuximab beta must start within 1 week of final SBRT dose (ideally 3 days after final SBRT dose)

[1113] 5 and will constitute protocol "Day 1"; dinutuximab beta will be administered every 5 weeks (35 days) + / - 3 days. Laboratory assessments can be completed up to 72 hours before the scheduled visit. d- Echocardiogram and electrocardiogram (12-lead ECG) should be performed at the Screening visit only. Electrocardiogram (6-lead-ECG) is acceptable in accordance with local standard of care e- Pregnancy test: For females of childbearing potential: At minimum, will be completed during Screening, within 72 hours of beginning

[1114] 10 SBRT, and within 72 hours of Day 1 of each cycle of dinutuximab beta f- Tumor imaging: Imaging studies will include cross sectional imaging (CT or MRI) and123I-MIBG scintigraphy. Participants with MIBG nonavid disease will undergo18FDG-PET Scintigraphy instead of123I-MIBG scintigraphy. [Brain imaging, if performed to document the stability of existing metastases at Screening, should be done by MRI if possible. If MRI is medically contraindicated, CT with contrast is an acceptable alternative. For participants without a history of brain metastases, head imaging is not required]. Imaging can be completed between days

[1115] 15 22-28 for administrative reasons or scheduling. g- Bilateral bone marrow aspirates and biopsies: Completed per institutional standards. h- Please obtain archival tumor tissue if available. If a biopsy is obtained as part of a clinical procedure, please obtain tumor tissue. i- Correlative studies blood collection (See Section 8.1.6.1 for volume of blood and additional details) j- Whole Blood Collection (Streck Cell Free DNA tube collection) for cfDNA studies [post-radiation or Cycle 1 / Day 1 of dinutuximab beta pre¬

[1116] 20 treatment; pre-treatment on Day 1 of every other odd cycle beginning with Cycle 3 (e.g. Cycle 3, 5, 7, etc.)]; Immunophenotyping and cytokine analysis (post-radiation or Cycle 1 / Day 1 of dinutuximab beta pre-treatment; pre-treatment on Cycle 3 / Dayl]; Fecal samples [post-radiation or Cycle 1 / Day 1 of dinutuximab beta pre-treatment; pre-treatment on Day 1 of every other odd cycle beginning with Cycle 3 (e.g. Cycle 3, 5, 7, etc.)]

[1117] k- Collect if evidence of disease progression

[1118] I- Follow up visits for participants who discontinue therapy without progressive disease every 8 weeks + / - 7 days; after 1 year, visits and imaging can every 12 weeks + / - 7 days. Every effort should be made to collect information regarding disease status until the start of new anti-cancer therapy, disease progression, death, or end of the study

[1119] 5 m- Survival follow up entails telephone calls to assess survival status every 12 weeks until death, withdrawal of consent, or the end of the trial, whichever occurs first.

Claims

CLAIMS1. A method of treating metastasis of a GD2-positive cancer in a patient in need thereof, the method comprising administering an anti-GD2 antibody, or fragment thereof, to the patient in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites.

2. The method according to claim 1, wherein the anti-GD2 antibody is a chimeric, humanized or CDR grafted anti-GD2 antibody, optionally wherein the antibody is a chimeric anti-GD2 antibody.

3. The method according to any one of claims 1 or 2, wherein the anti-GD2 antibody is a chimeric, humanized or CDR grafted antibody comprising a light chain variable region in which CDR1, CDR2 and CDR3 comprise the amino acid sequences of SEQ ID NO: 5, SEQ ID NO: 6 and SEQ ID NO: 7, respectively; and a heavy chain variable region in which CDR1, CDR2 and CDR3 comprise the amino acid sequences of SEQ ID NO: 8, SEQ ID NO: 9 and SEQ ID NO: 10, respectively; and a constant region derived from a human IgG antibody or a humanised IgG antibody.

4. The method according to any one of claims 1 to 3, wherein the anti-GD2 antibody is selected from dinutuximab, dinutuximab beta, and naxitamab.

5. The method according to any one of claims 1 to 4, wherein the anti-GD2 antibody is dinutuximab beta.

6. The method according to any one of claims 1 to 5, wherein the GD2-positive cancer is neuroblastoma, ganglioneuroblastoma, glioblastoma, medulloblastoma, astrocytoma, melanoma, small- cell lung cancer, desmoplastic small round cell tumor, osteosarcoma, rhabdomyosarcoma, or another soft tissue sarcoma, preferably wherein the GD2-positive cancer is neuroblastoma.

7. The method according to any one of claims 1 to 6, wherein the GD2-positive cancer is relapsed or refractory, such as relapsed or refractory neuroblastoma.

8. The method according to any one of claims 1 to 7, wherein the patient has at least one metastatic tumor lesion suitable for SBRT.

9. The method according to claim 8, wherein:(a) the patient has at least one metastatic tumor lesion in the lung, liver, mediastinal / cervical nodes, spinal / paraspinal / osseous, or abdominal-pelvic (lymph node / adrenal gland) region suitable for SBRT; or(b) the patient has at least one metastatic tumor lesion in the mediastinal / cervical nodes, spinal / paraspinal / osseous, or abdominal-pelvic (lymph node / adrenal gland) region suitable for SBRT.

10. The method according to any one of claims 1 to 9, wherein the patient has at least one metastatic tumor lesion that has a diameter > 10 mm in at least one dimension, optionally where the diameter is measured using MRI or CT scan.

11. The method according to any one of claims 1 to 10, wherein the patient has at least one metastatic tumor lesion that is a discrete lymph node with a diameter greater than or equal to 15 mm on its short axis, optionally where the diameter is measured using MRI or CT scan.

12. The method according to any one of claims 1 to 11, wherein the patient has at least one metastatic tumor lesion that is MIBG avid or demonstrates increased FDG uptake on PET scan.

13. The method according to any one of claims 1 to 12, wherein the SBRT is administered in a dose of 10-50 Gy per site, such as 10 Gy, 12.5 Gy, 15 Gy, 17.5 Gy, 20 Gy, 22.5 Gy, 25 Gy, 27.5 Gy, 30 Gy, 35 Gy, 40 Gy, 45 Gy or 50 Gy at one or more sites, optionally wherein the SBRT dose is different between two or more sites.

14. The method according to any one of claims 1 to 13, wherein the SBRT is administered at an initial dose and wherein one or more subsequent doses are administered at a reduced dose.

15. The method according to any one of claims 1 to 14, wherein the SBRT at the one or more metastatic sites is completed within a total period of up to 1 week.

16. The method according to any one of claims 1 to 15, wherein administration of the anti-GD2 antibody is initiated within 1 week of completion of administration of the SBRT at the one or more metastatic sites, optionally within 3 days of completion of administration of the SBRT at the one or more metastatic sites, preferably wherein the anti-GD2 antibody is dinutuximab beta.

17. The method according to any one of claims 1 to 16, wherein the anti-GD2 antibody is administered at a cumulative dose of up to 3000 mg / m2, such as at a cumulative dose of at least 100 mg / m2, such as from 100 to 200 mg / m2, from 200 to 300 mg / m2, from 300 to 400 mg / m2, from 400 to 500 mg / m2, from 500 to 600 mg / m2, from 600 to 700 mg / m2, from 700 to 800 mg / m2, from 800 to 900 mg / m2, from 900 to 1000 mg / m2, from 1000 to 1100 mg / m2, from 1100 to 1200 mg / m2, from 1200 to1300 mg / m2, from 1300 to 1400 mg / m2, from 1400 to 1500 mg / m2, from 1500 to 1600 mg / m2, from 1600 to 1700 mg / m2, from 1700 to 1800 mg / m2, from 1800 to 1900 mg / m2, from 1900 to 2000 mg / m2, from 2000 to 2100 mg / m2, from 2100 to 2200 mg / m2, from 2200 to 2300 mg / m2, from 2300 to 2400 mg / m2, from 2400 to 2500 mg / m2, from 2500 to 2600 mg / m2, from 2600 to 2700 mg / m2, from 2700 to 2800 mg / m2, from 2800 to 2900 mg / m2, or from 2900 to 3000 mg / m2, preferably wherein the anti-GD2 antibo jy is dinutuximab beta.

18. The method according to any one of claims 1 to 17, wherein the anti-GD2 antibody is administered to the patient in a dose of up to 200 mg / m2per cycle during one or more cycles, such as during 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 cycles, preferably wherein the anti-GD2 antibody is dinutuximab beta.

19. The method according to claim 18, wherein the anti-GD2 antibody is administered to the patient in a dose per cycle that is equal for all cycles during which the anti-GD2 antibody is administered, such as wherein the anti-GD2 antibody is administered to the patient in a dose per cycle that is at least 10 mg / m2per cycle, such as from 10 to 30 mg / m2per cycle, from 20 to 40 mg / m2per cycle, from 30 to 50 mg / m2per cycle, from 40 to 60 mg / m2per cycle, from 50 to 70 mg / m2per cycle, from 60 to 80 mg / m2per cycle, from 70 to 90 mg / m2per cycle, from 80 to 100 mg / m2per cycle, from 90 to 110 mg / m2per cycle, from 100 to 120 mg / m2per cycle, from 110 to 130 mg / m2per cycle, from 120 to 140 mg / m2per cycle, from 130 to 150 mg / m2per cycle, from 140 to 160 mg / m2per cycle, from 150 to 170 mg / m2per cycle, from 160 to 180 mg / m2per cycle, from 170 to 190 mgm2per cycle, from 180 to 200 mg / m2per cycle, or from 190 to 200 mg / m2per cycle, preferably wherein the anti-GD2 antibody is dinutuximab beta.

20. The method according to claim 18, wherein the anti-GD2 antibody is administered to the patient in a dose per cycle that varies by up to 20 mg / m2such as up to 10 mg / m2between different cycles during which the anti-GD2 antibody isadministered, such as wherein the anti-GD2 antibody is administered to the patient in a dose per cycle of at least 10 mg / m2per cycle for all cycles, such as: from 10 to 30 mg / m2per cycle for one or more cycles and from 20 to 40 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 20 to 40 mg / m2per cycle for one or more cycles and from 30 to 50 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 20 to 40 mg / m2per cycle for one or more cycles and from 40 to 60 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 40 to 60 mg / m2per cycle for one or more cycles and from 60 to 80 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 60 to 80 mg / m2per cycle for one or more cycles and from 80 to 100 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 100 to 120 mg / m2per cycle for one or more cycles and from 120 to 140 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 120 to 140 mg / m2per cycle for one or more cycles and from 140 to 160 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 140 to 160 mg / m2per cycle for one or more cycles and from 160 to 180 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; or from 160 to 180 mg / m2per cycle for one or more cycles and from 180 to 200 mg / m2per cycle for the other cycles during which the anti-GD2 antibody is administered; preferably wherein the anti-GD2 antibody is dinutuximab beta.

21. The method according to any one of claims 18 to 20, wherein the anti-GD2 antibody is administered to the patient in a dose per cycle of 20 mg / m2, 30 mg / m2, 40 mg / m2, 50 mg / m2, 60 mg / m2, 70 mg / m2, 80 mg / m2, 90 mg / m2, 100 mg / m2, 110 mg / m2, 120 mg / m2, 130 mg / m2, 140 mg / m2, 150 mg / m2, 160 mg / m2, 170 mg / m2, 180 mg / m2, 190 mg / m2, or 200 mg / m2.

22. The method according to any one of claims 1 to 21, wherein the anti-GD2 antibody is administered to the patient at a dose of at least 1 mg / m2 / day, such as from 1 to 2 mg / m2 / day, from 2 to 3 mg / m2 / day, from 3 to 4 mg / m2 / day, from 4 to 5 mg / m2 / day, from 5 to 6 mg / m2 / day, from 6 to 7 mg / m2 / day, from 7 to 8 mg / m2 / day, from 8 to 9 mg / m2 / day, from 9 to 10 mg / m2 / day, or 10 mg / m2 / day.

23. The method according to any one of claims 1 to 22, wherein when the patient has a weight of greater than 12 kg, the anti-GD2 antibody is administered to the patient at a dose of 10 mg / m2 / day, and wherein when the patient has a weight of from greater than 5 kg to 12 kg, the anti-GD2 antibody is administered to the patient at a dose of0.33 mg / kg / day, and wherein when the patient has a weight of 5 kg or less, the anti- GD2 antibody is administered to the patient at a dose of 0.22 mg / kg / day.

24. The method according to any one of claims 18 to 23, wherein the one or more cycles during which the anti-GD2 antibody is administered are of 35 ± 3 days per cycle, optionally of 35 days per cycle.

25. The method according to any one of claims 1 to 24, wherein the anti-GD2 antibody is administered to the patient in a daily dose of 1, 2, 3, 4, 5, 6, 7, 7.5, 8, 9, 10, 11, 12, 12.5, 13, 14, 15, 16, 17, 17.5, 18, 19, 20, 21, 22, 22.5, 23, 24 or 25 mg / m2.

26. The method according to claim 25, wherein the anti-GD2 antibody is administered to the patient in a daily dose of 7, 10, 15 or 20 mg / m2.

27. The method according to any one of claims 1 to 26, wherein the anti-GD2 antibody is administered to the patient as a continuous intravenous infusion over 24 hours per day, optionally wherein the continuous intravenous infusion of the anti-GD2 antibody is in a daily dose of 10 mg / m2.

28. The method according to any one of claims 1 to 26, wherein the anti-GD2 antibody is administered to the patient on consecutive days of a cycle until all of the dose per cycle of the anti-GD2 antibody has been administered.

29. The method according to claim 28, wherein the anti-GD2 antibody is administered to the patient as 5 daily discontinuous infusions of 20 mg / m2, each over 8 hours, on the first 5 days of each cycle.

30. The method according to any one of claims 1 to 29, wherein the administration of the anti-GD2 antibody improves one or more clinical parameters compared to the SBRT administered without the anti-GD2 antibody, such as wherein the one of more clinical parameters are selected from overall response rate, complete response rate, partial response rate, primary tumour volume reduction, Curie score, event-free survival, and overall survival, overall response during and after induction (primary tumor, metastases), and metastatic CR and PR rates.

31. The method according to any one of claims 1 to 30, wherein the anti-GD2 antibody is administered without concomitant administration of IL-2.

32. The method according to any one of claims 1 to 31, wherein the anti-GD2 antibody has a predetermined overall patient dose and wherein the anti-GD2 antibody is administered for a treatment period until the predetermined overall patient dose has been administered.

33. The method according to any one of claims 1 to 31, the anti-GD2 antibody is administered for a treatment period until a certain therapeutic effect has been reached.

34. The method according to any one of claims 1 to 33, wherein the anti-GD2 antibody is administered by using a mini-pump.

35. The method according to any one of claims 1 to 34, wherein the administration of the anti-GD2 antibody is accompanied by the administration of morphine and / or one or more other analgesics.

36. The method according to claim 35, wherein morphine is administered only for some but not all days on which the anti-GD2 antibody is administered.

37. The method according to claim 35 or 36, wherein the morphine dose administered during one or more hours or days of the administration of the anti-GD2 antibody and / or of all morphine treatment hours or days is lower than 50 mcg / kg / h, or lower than 30 mcg / kg / h.

38. The method according to any one of claims 35 to 37, wherein the dose of the one or more analgesics, optionally morphine, is to be reduced within the overall treatment time, within a treatment cycle, during the antibody treatment period within a treatment cycle, from one antibody treatment day to the next antibody treatment day within a treatment cycle, and / or from one treatment cycle to the next.

39. The method according to any one of claims 35 to 38, wherein the morphine dose is to be continuously reduced within a treatment cycle, during the antibody treatment period within a treatment cycle, and / or from one antibody treatment day to the next antibody treatment day within a treatment cycle.

40. An anti-GD2 antibody for use in a method of treating metastasis in a GD2- positive cancer in a patient by administering anti-GD2 antibody to the patient incombination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites, preferably wherein the anti-GD2 antibody is dinutuximab beta.

41. Use of an anti-GD2 antibody in the preparation of a medicament for treating metastasis in a GD2-positive cancer in a patient, wherein the medicament is for administration to the patient in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites, preferably wherein the anti-GD2 antibody is dinutuximab beta.

42. Use of an anti-GD2 antibody for treating metastasis in a GD2-positive cancer in a patient in combination with stereotactic body radiotherapy (SBRT) at one or more metastatic sites, preferably wherein the anti-GD2 antibody is dinutuximab beta.

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