Combination therapies for the treatment of cd33-positive hematological malignancies harboring mutations

Abstract

Provided are methods for treating CD33-positive hematological malignancies, such as acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS), harboring mutations such as FLT3, IDH1, IDH2, NMP1, and / or MLL1 gene mutations, using combination therapy that includes one or both of a radiolabeled CD33-targeting agent and a drug-conjugated CD33-targeting agent, and one or more targeted therapies, such as FLT3, IDH and Menin inhibitors.

Description

COMBINATION THERAPIES FOR THE TREATMENT OF CD33-POSITIVE HEMATOLOGICAL MALIGNANCIES HARBORING MUTATIONSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit U.S. Provisional Application No. 63 / 505,649, filed June 1, 2023, U.S. Provisional Application No. 63 / 517,040, filed August 1, 2023, and U.S. Provisional Application No. 63 / 578,282, filed August 23, 2023, the entire contents of each of which is incorporated herein by reference.SEQUENCE LISTING

[0002] The instant application contains a Sequence Listing which has been submitted electronically in XML format and is hereby incorporated by reference in its entirety. Said XML copy, created on June 3, 2024, is named ATNM-026P_SL_ST26.xml and is 11,818 bytes in size.FIELD OF THE INVENTION

[0003] The presently claimed invention relates to the field of targeted radiotherapies for the treatment of cancer.BACKGROUND

[0004] Overexpression of CD33 is common in many hematological malignancies, including AML, CML, and MDS. In AML, 85-90% of patients express CD33, which has led to the development of targeted therapies. Approximately 96% of MDS patients express CD33 on their myeloblasts (Sanford et al., "CD33 is frequently expressed in cases of myelodysplastic syndrome and chronic myelomonocytic leukemia with elevated blast count," 2016, Leukemia & Lymphoma, vol. 57(8): 1965-1968). In another study, MDS patients demonstrated approximately twice as many CD33 molecules per bone marrow cell as the control samples (Jilani, et al., "Differences in CD33 intensity between various myeloid neoplasms," 2002, Am J Clin Pathol 2002, vol. 118:560-566). The CD33 antigen is expressed on virtually all cases of CML.

[0005] In addition, many CD33 -expressing hematological cancers, such as AML, bear cancer driving mutations such as mutations in the FLT3, IDH1, IDH2, NMP1, and / or MLL1 genes. For example, FLT3 mutations are the most common genetic alteration in AML, present in approximately one third of newly diagnosed patients. FLT3 internal tandem duplication mutations (FLT3-ITD) have been shown to be associated with increased relapse and inferior overall survival.

[0006] What is needed and provided by the various aspects of the present invention are new and improved methods for treating CD33 -positive hematological malignancies that harbor cancer-driving mutations.SUMMARY OF THE INVENTION

[0007] In one aspect, the invention provides a method for treating a hematological malignancy including CD33-positive malignant cells, such as acute myeloid leukemia or myelodysplastic syndrome, in a mammalian subject, such as a human patient, including the steps of: administering to the subject an amount of a radiolabeled anti-CD33 antibody effective to kill or inhibit the proliferation of the CD33-positive malignant cells in the subject, wherein the radiolabeled anti-CD33 antibody is labeled with a radionuclide including131I,125I,123I,90Y,177LU,186Re,188Re,89Sr,153Sm,32P,225Ac,213Po,211At,212Bi,213Bi,223Ra,227Th,149Tb,137Cs,212Pb,103Pd or any combination thereof; and administering one or more of a FLT3 inhibitor, an IDH1 inhibitor, an IDH2 inhibitor, and a Menin inhibitor to the subject.

[0008] The hematological malignancy may, for example, be characterized by mutations in one or more of the FLT3, IDH1, IDH2, NMP1, and MLL1 genes.

[0009] Additional features, advantages, and aspects of the invention may be set forth or apparent from consideration of the following detailed description, drawings if any, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 shows the 48-hour viability results for human MV411 AML model cells treated with unlabeled lintuzumab, 225Ac-labeled lintuzumab at different radiation doses (nCi / ml), the FLT3 inhibitor Gilteritinib at different concentrations (nM), and no treatment control.

[0011] FIGS. 2A and 2B shows the 48-hour viability results for human MV411 AML model cells treated with 225Ac-labeled lintuzumab at different radiation doses (nCi / ml) alone, the FLT3 inhibitor Gilteritinib at different concentrations (nM) alone, and 225Ac-labeled lintuzumab and Gilteritinib in different combinations.

[0012] FIG. 3 shows, from a first experiment, the 48-hour viability results for human MV411 AML model cells treated with unlabeled lintuzumab, 225Ac-labeled IgG (non-specific) at different radiation doses (nCi / ml), 225Ac-labeled lintuzumab at different radiation doses(nCi / ml), anti-CD33 ADC Gemtuzumab ozogamicin (GO) at different concentrations, the FLT3 inhibitor Gilteritinib at different concentrations (nM), and no treatment control.

[0013] FIGS. 4A and 4B show (from a second experiment) the 48-hour viability results for human MV411 AML model cells treated with 225 Ac-labeled lintuzumab at different radiation doses (nCi / ml) alone, the FLT3 inhibitor Gilteritinib at different concentrations (nM) alone, and 225Ac-labeled lintuzumab and Gilteritinib in different combinations.

[0014] FIGS. 5A and 5B show the 48-hour viability results for human MV411 AML model cells treated with GO (0 pg / ml, 0.05 pg / ml, or 0.1 pg / ml) in combination with the FLT3 inhibitor Gilteritinib (at 0 nM, 10 nM or 20 nM).

[0015] FIG. 6A shows the 48-hour viability results for human MV411 AML model cells treated with the menin inhibitors Revumenib or Ziftomenib at different concentrations (nM), and no treatment control.

[0016] FIG. 6B shows the 72-hour viability results for human MV411 AML model cells treated with unlabeled lintuzumab, 225 Ac-labeled lintuzumab at different radiation doses (nCi / ml), or the menin inhibitors Revumenib or Ziftomenib at different concentrations (nM), and no treatment control.

[0017] FIGS. 7A and 7B show the 48-hour viability results for human MV411 AML model cells treated with GO (0 pg / ml, 0.05 pg / ml, or 0.1 pg / ml) in combination with the menin inhibitor Revumenib (at 0 nM, 100 nM or 300 nM).

[0018] FIGS. 8A and 8B show the 48-hour viability results for human MV411 AML model cells treated with225Ac-lintuzumab (0 nCi / ml, 1 nCi / ml or 10 nCi / ml) in combination with the menin inhibitor Revumenib (at 0 nM, 100 nM or 300 nM).

[0019] FIGS. 9A and 9B show the 48-hour viability results for human MV411 AML model cells treated with GO (0 pg / ml, 0.05 pg / ml, or 0.1 pg / ml) in combination with the menin inhibitor Ziftomenib (at 0 nM, 100 nM or 300 nM).

[0020] FIGS. 10A and 10B show the 48-hour viability results for human MV411 AML model cells treated with225Ac-lintuzumab (0 nCi / ml, 1 nCi / ml or 10 nCi / ml) in combination with the menin inhibitor Ziftomenib (at 0 nM, 100 nM or 300 nM).

[0021] FIG. 11 shows the 48-hour viability results for human MV411 AML model cells (FLT3-ITD) treated with a combination of225Ac-lintuzumab and Gilteritinib or225Ac- lintuzumab and Midostaurin, versus various controls.

[0022] FIG. 12 shows the 48-hour viability results for human MOLM-13 AML model cells (FLT3-ITD) treated with a combination of225Ac-lintuzumab and Gilteritinib or225Ac- lintuzumab and Midostaurin, versus various controls.DETAILED DESCRIPTION

[0023] In one aspect, the invention provides methods for treating CD33 -positive hematological malignancies, such as acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) harboring cancer-driving mutations such as FLT3, IDH1, IDH2, NMP1 (nucleophosmin gene), and / or MLL1 gene mutations, using combination therapy including treatment with a radiolabeled CD33 -targeting agent, such as 255Ac-labeled lintuzumab (e.g., 225Ac lintuzumab satetraxetan a / k / a Actimab-A™, Actinium Pharmaceuticals, Inc., New York, NY), and one or more targeted therapies, such as one or more of a FLT3, IDH1, IDH2 and Menin inhibitor.

[0024] In a related aspect, subjects having CD33 -positive hematological malignancies with cancer-driving mutations in one or more of the FLT3, IDH1, IDH2, NMP1, and / or MLL1 genes may, for example, be treated using a radiolabeled CD33 -targeting agent in conjunction with an inhibitor of the gene product of the respective cancer-driving mutated gene or an inhibitor of a gene product in the same pathway as the gene product of the mutated cancer-driving gene. Thus, for example, Menin inhibitors may be used in the treatment of cancers having a cancerdriving mutation in one or both of the NMP1 and MLL1 genes.

[0025] The CD33 -positive hematological malignancy treated by the methods of the invention may, for example, be multiple myeloma (MM), acute myeloid leukemia (AML), chronic myelogenous leukemia (CML), myelodysplastic syndrome (MDS), or a myeloproliferative neoplasm. The hematological malignancy may, for example, be a relapsed and / or refractory (R / R) form or occurrence of: multiple myeloma, acute myeloid leukemia, chronic myelogenous leukemia, myelodysplastic syndrome, or a myeloproliferative neoplasm. The hematological malignancy may, for example, be refractory and / or resistant to treatment with a Bcl-2 inhibitor, such as venetoclax. The subject may, for example, have been previously treated with a Bcl-2 inhibitor such as venetoclax. The CD33 -positive hematological malignancy may, for example, have a TP53 (p53) mutation, i.e., the CD33-positive hematological malignancy may, for example, be a TP53-mutated CD33-positive hematological malignancy, such as TP53-mutated AML.

[0026] As used herein, the term "subject" includes, without limitation, a mammal such as a human, a non-human primate, a dog, a cat, a horse, a sheep, a goat, a cow, a rabbit, a pig, a ratand a mouse. Where the subject is human, the subject can be of any age. For example, the subject can be 60 years or older, 65 or older, 70 or older, 75 or older, 80 or older, 85 or older, or 90 or older. Alternatively, the subject can be 50 years or younger, 45 or younger, 40 or younger, 35 or younger, 30 or younger, 25 or younger, or 20 or younger. For a human subject afflicted with cancer, the subject may be newly diagnosed, or relapsed and / or refractory, or in remission. The subject may, for example, be a high-risk CD33-positive hematological malignancy patient such as a high-risk AML patient such as a high-risk R / R AML patient.

[0027] In general, the radiolabeled CD33 targeting agents, such as monoclonal antibodies or antigen-binding fragments thereof, used in the various aspects of the invention may be labeled with one or more of the following radionuclides:131I,125I,123I,90Y,177Lu,186Re,188Re,89Sr,153Sm,32P,225AC,213PO,211At,212Bi,213Bi,223Ra,227Th,149Tb,137Cs,212Pb, and103Pd. Radioisotopes of Iodine may, for example, be chemically conjugated to the targeting agent. For other radionuclides, such as225Ac and177Lu, it is convenient to chemically conjugate a chelator (chelator moiety), such as DOTA or a derivative thereof, to the targeting agent and radiolabel the targeting agent by chelation of the radionuclide to the conjugated chelator.

[0028] The chelator group in the various aspects of the invention may, for example, include: l,4,7,10-tetraazacyclododecane-l,4,7-triacetic acid (D03A) or a derivative thereof; 1,4,7- triazacyclononane-l,4-diacetic acid (NODA) or a derivative thereof; 1,4,7-triazacyclononane- 1,4,7-triacetic acid (NOTA) or a derivative thereof; 1,4,7, 10-tetraazacyclododecane-l, 4, 7,10- tetraacetic acid (DOTA) or a derivative thereof; 1,4,7-triazacyclononane, 1 -glutaric acid-4, 7- diacetic acid (NOD AGA) or a derivative thereof; 1,4,7, 10-tetraazacyclodecane, 1 -glutaric acid-4,7, 10-triacetic acid (DOTAGA) or a derivative thereof; 1,4,8,11- tetraazacyclotetradecane-l,4,8,l l-tetraacetic acid (TETA) or a derivative thereof; 1,4,8,11- tetraazabicyclo[6.6.2]hexadecane-4,l l-diacetic acid (CB-TE2A) or a derivative thereof; diethylene triamine pentaacetic acid (DTP A), its diester, or a derivative thereof; 2-cyclohexyl diethylene triamine pentaacetic acid (CHX-A"-DTPA) or a derivative thereof; deforoxamine (DFO) or a derivative thereof; l,2-[[6-carboxypyridin-2-yl]methylamino]ethane (Fkdedpa) or a derivative thereof; DADA or a derivative thereof; 1,4,7, 10-Tetraazacyclododecane-l, 4, 7,10- tetra(methylene phosphonic acid) (DOTP) or a derivative thereof; 4-amino-6-[[16-[(6- carboxypyridin-2-yl)m ethyl]- 1 ,4, 10,13 -tetraoxa-7, 16-diazacyclooctadec-7- yl]methyl]pyridine-2-carboxylic acid (MACROP A-NEE) or a derivative thereof; MACROPA or a derivative thereof; l,4,7,10-tetrakis(carbamoylmethyl)-l,4,7,10-tetraazacyclododecane (TCMC) or a derivative thereof; {4-[2-(bis-carboxymethylamino)-ethyl]-7-carboxymethyl-[l,4,7]triazonan-l-yl}-acetic acid (NETA) or a derivative thereof; Diamsar or a derivative thereof; l,4,7-triazacyclononane-l,4,7-tris[methyl(2-carboxyethyl)phosphinic acid (TRAP, PRP9, TRAP-Pr) or a derivative thereof; N,N'-bis(6-carboxy-2- pyridylmethyl)ethylenediamine-N,N'-diacetic acid (H4octapa) or a derivative thereof; N,N'- [l-benzyl-l,2,3-triazole-4-yl]methyl-N,N'-[6-(carboxy)pyridin-2-yl]-l,2-diaminoethane (H2azapa) or a derivative thereof; N,N''-[[6-(carboxy)pyridin-2-yl]methyl]diethylenetriamine- N,N',N"-triacetic acid (H5decapa) or a derivative thereof; N,N'-bis(2-hydroxy-5- sulfobenzyl)ethylenediamine-N,N'-diacetic acid (SHBED) or a derivative thereof; N,N'-bis(2- hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) or a derivative thereof; 3,6,9,15- tetraazabicyclo[9.3.1]pentadeca-l(15),l l,13-triene-3, 6, 9, -triacetic acid (PCTA) or a derivative thereof; desferrioxamine B (DFO) or a derivative thereof; N,N'-(methylenephosphonate)-N,N'- [6-(m ethoxy carbonyl)pyridin-2-yl]methyl-l,2-diaminoethane (H6phospa) or a derivative thereof; l,4,7,10,13,16-hexaazacyclohexadecane-N,N',N'',N''',N'''',N''"'-hexaacetic acid (HEHA) or a derivative thereof; 1,4,7, 10, 13-pentaazacyclopentadecane-N,N',N'',N''',N'"'- pentaacetic acid (PEPA) or a derivative thereof; or 3,4,3-LI(l,2-HOPO) or a derivative thereof.

[0029] The chelator group in the various aspects of the invention may, for example, include a chelator group selected from:

[0030] As used herein, the term “antibody” includes, without limitation, (a) an immunoglobulin molecule including two heavy chains and two light chains and which recognizes an antigen; (b) polyclonal and monoclonal immunoglobulin molecules; (c) monovalent and divalent fragments thereof, such as Fab, di-Fab, scFv, diabodies, minibodies, and nanobodies (sdAb); (d) naturally occurring and non-naturally occurring, such as wholly synthetic antibodies, IgG-Fc-silent, and chimeric; and (e) bi-specific forms thereof. Immunoglobulin molecules may, for example, derive from any of the commonly known classes, including but not limited to IgA, secretory IgA, IgG and IgM. IgG subclasses are also well known to those in the art and include, but are not limited to, human IgGl, IgG2, IgG3 and IgG4. The N-terminus of each chain defines a “variable region” of about 100 to 110 or moreamino acids primarily responsible for antigen recognition. The terms variable light chain (VL) and variable heavy chain (VH) refer to these regions of light and heavy chains respectively. Antibodies may be human, humanized or nonhuman. When a specific aspect of the presently disclosed invention refers to or recites an “antibody,” it is envisioned as referring to any of the full-length antibodies or fragments thereof disclosed herein, unless explicitly denoted otherwise.

[0031] A “humanized” antibody refers to an antibody in which some, most or all amino acids outside the CDR domains of a non-human antibody are replaced with corresponding amino acids derived from human immunoglobulins. In one embodiment of a humanized form of an antibody, some, most or all of the amino acids outside the CDR domains have been replaced at corresponding positions with amino acids from human immunoglobulins, whereas some, most or all amino acids within one or more CDR regions are unchanged. CDRs and framework regions with the variable domains of antibodies may, for example, be delineated according to the Kabat convention. Small additions, deletions, insertions, substitutions or modifications of amino acids are permissible as long as they do not abrogate the ability of the antibody to bind to a particular antigen. A “humanized” antibody retains an antigenic specificity similar to that of the original antibody.

[0032] A “chimeric antibody” refers to an antibody in which the variable regions are derived from one species and the constant regions are derived from another species, such as an antibody in which the variable regions are derived from a mouse antibody and the constant regions are derived from a human antibody.

[0033] Compositions including a radiolabeled antibody or radiolabeled antigen-binding antibody fragment may include one or more pharmaceutically acceptable carriers or pharmaceutically acceptable excipients. Such carriers are well known to those skilled in the art. For example, injectable drug delivery systems include solutions, suspensions, gels, microspheres and polymeric injectables, and can include excipients such as solubility-altering agents (e.g., ethanol, propylene glycol and sucrose) and polymers (e.g., polycaprylactones and PLGA's). An exemplary formulation may be as substantially described in International Pub. No. WO 2017 / 155937, incorporated by reference herein. For example, according to certain aspects, the formulation may include 0.5% to 5.0% (w / v) of an excipient selected from the group consisting of ascorbic acid, polyvinylpyrrolidone (PVP), human serum albumin (HSA), a water-soluble salt of HSA, and mixtures thereof. Certain formulations may include 0.5-5%ascorbic acid; 0.5-4% polyvinylpyrrolidone (PVP); and the monoclonal antibody in 50 mM PBS buffer, pH 7.

[0034] Although throughout the present disclosure various aspects or elements thereof are described in terms of “including” or “comprising,” it should be understood that corresponding aspects or elements thereof described in terms of “consisting essentially of’ or “consisting of’ are similarly disclosed and provided by this disclosure. For example, while certain aspects of the invention have been described in terms of a method “including” or “comprising” administering a radiolabeled antibody, corresponding methods instead reciting “consisting essentially of’ or “consisting of’ administering the radiolabeled antibody are also within the scope of said aspects and disclosed by this disclosure.

[0035] Methods for preparing225Ac-labeled radioimmunoconjugates, such as225Ac-labeled lintuzumab (HuM195) and pharmaceutical compositions thereof, are further disclosed, for example, in Applicant’s U.S. Patent No. 9,603,954, which methods may be used to produce225Ac-labeled anti-CD33 antibodies, and respective pharmaceutical compositions thereof, for use in the various aspects of the present invention. The full-length nucleotide sequence and the encoded amino acid sequence of the lintuzumab light chain (including leader sequence) are disclosed as SEQ ID NO: 1 and SEQ ID NO:2 respectively. The full-length nucleotide sequence and the encoded amino acid sequence of the lintuzumab heavy chain (including leader sequence) are disclosed as SEQ ID NO:3 and SEQ ID NO:4 respectively.

[0036] FIG. 1 shows the 48-hour viability results for human MV411 AML model cells treated with unlabeled lintuzumab, 225Ac-labeled lintuzumab at different radiation doses (nCi / ml), the FLT3 inhibitor Gilteritinib at different concentrations (nM), and no treatment control.

[0037] FIGS. 2A and 2B shows the 48-hour viability results for human MV411 AML model cells treated with 225Ac-labeled lintuzumab at different radiation doses (nCi / ml) alone, the FLT3 inhibitor Gilteritinib at different concentrations (nM) alone, and 225Ac-labeled lintuzumab and Gilteritinib in different combinations.

[0038] FIG. 3 shows the 48-hour viability results for human MV411 AML model cells treated with unlabeled lintuzumab, 225Ac-labeled IgG (non-specific) at different radiation doses (nCi / ml), 225 Ac-labeled lintuzumab at different radiation doses (nCi / ml), anti-CD33 ADC Gemtuzumab ozogamicin (GO) at different concentrations, the FLT3 inhibitor Gilteritinib at different concentrations (nM), and no treatment control.

[0039] FIGS. 4A and 4B show (from a second experiment) the 48-hour viability results for human MV411 AML model cells treated with 225 Ac-labeled lintuzumab at different radiationdoses (nCi / ml) alone, the FLT3 inhibitor Gilteritinib at different concentrations (nM) alone, and 225Ac-labeled lintuzumab and Gilteritinib in different combinations.

[0040] These experiments demonstrate that combinations of 225Ac-labeled lintuzumab and Gilteritinib specifically enhance MV411 cell killing versus either agent alone.

[0041] FIGS. 5A and 5B show the 48-hour viability results for human MV411 AML model cells treated with GO (at 0 pg / ml, 0.05 pg / ml, or 0.1 pg / ml) in combination with the FLT3 inhibitor Gilteritinib (at 0 nM, 10 nM or 20 nM).

[0042] FIG. 6A shows the 48-hour viability results for human MV411 AML model cells treated with the menin inhibitors Revumenib or Ziftomenib at different concentrations (nM), and no treatment control.

[0043] FIG. 6B shows the 72-hour viability results for human MV411 AML model cells treated with unlabeled lintuzumab, 225 Ac-labeled lintuzumab at different radiation doses (nCi / ml), or the menin inhibitors Revumenib or Ziftomenib at different concentrations (nM), and no treatment control.

[0044] FIGS. 7A and 7B show the 48-hour viability results for human MV411 AML model cells treated with GO (at 0 pg / ml, 0.05 pg / ml, or 0.1 pg / ml) in combination with the menin inhibitor Revumenib (at 0 nM, 100 nM or 300 nM).

[0045] FIGS. 8A and 8B show the 48-hour viability results for human MV411 AML model cells treated with225Ac-lintuzumab (0 nCi / ml, 1 nCi / ml or 10 nCi / ml) in combination with the menin inhibitor Revumenib (at 0 nM, 100 nM or 300 nM).

[0046] FIGS. 9A and 9B show the 48-hour viability results for human MV411 AML model cells treated with GO (at 0 pg / ml, 0.05 pg / ml, or 0.1 pg / ml) in combination with the menin inhibitor Ziftomenib (at 0 nM, 100 nM or 300 nM).

[0047] FIGS. 10A and 10B show the 48-hour viability results for human MV411 AML model cells treated with225Ac-lintuzumab (0 nCi / ml, 1 nCi / ml or 10 nCi / ml) in combination with the menin inhibitor Ziftomenib (at 0 nM, 100 nM or 300 nM).

[0048] FIGS. 11 and 12 show that225Ac-lintuzumab (Lint-Ac225) potentiates cytotoxicity in combination with the FLT3 inhibitor Gilteritinib (Gilt) or Midostaurin (Mido) for FLT3-ITD AML cell lines MV-411 (a / k / a MV-4-11; FIG. 11) and MOLM-13 (FIG. 12), versus treatment with the single agents alone. Dosing of each agent was selected based on the monotherapy data findings. After incubation with225Ac-lintuzumab (or control) in growth media for Ihr, the media was changed for fresh media with Gilteritinib or Midostaurin (or control), and viability was then measured at 48hrs. Each sample was tested in triplicate. Multiple t test statisticalanalysis comparing combination therapy to each monotherapy was performed using GraphPad Prism software. (Key: *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001, ns=not significant, error bars represent SD.)

[0049] The 225 Ac-labeled lintuzumab used in all experiments was 225 Ac-labeled, p-SCN-Bn- DOTA conjugated lintuzumab.

[0050] Without limitation, the invention further provides the following enumerated aspects / embodiments:

[0051] Aspect 1. A method for treating a hematological malignancy including CD33-positive malignant cells in a mammalian subject, such as a human patient, including the steps of: administering to the subject one or both of(i) an amount of a radiolabeled anti-CD33 antibody effective to kill or inhibit the proliferation of the CD33 -positive malignant cells in the subject, wherein the radiolabeled anti-CD33 antibody is labeled with a radionuclide including131I,125I,123I,90Y,177LU,186Re,188Re,89Sr,153Sm,32P,225Ac,213Po,211At,212Bi,213Bi,223Ra,227Th,149Tb,137Cs,212Pb,103Pd or any combination thereof, and(ii) an amount of an anti-CD33 antibody radioconjugate (anti-CD33 ADC), such as but not limited to gemtuzumab ozogamicin (GO), effective to kill or inhibit the proliferation of the CD33 -positive malignant cells in the subject; and administering one or more of a FLT3 inhibitor, an IDH1 inhibitor, an IDH2 inhibitor, and a Menin inhibitor to the subject.

[0052] Aspect 2. The method of aspect 1, wherein the step of administering to the subject an amount of a radiolabeled anti-CD33 antibody effective to kill or inhibit the proliferation of the CD33-positive malignant cells in the subject, is performed before the step of administering one or more of a FLT3 inhibitor, an IDH1 inhibitor, an IDH2 inhibitor, and a Menin inhibitor to the subject.

[0053] Aspect 3. The method of aspect 1 or 2, wherein the radiolabeled anti-CD33 antibody includes radiolabeled lintuzumab (HuM195), radiolabeled gemtuzumab, radiolabeled vadastuximab, a radiolabeled antibody including the heavy chain complementarity determining regions (CDRs) and / or the light chain CDRs of any of the preceding antibodies, a radiolabeled antibody including the heavy chain variable region and / or the light chain variable region of any of the preceding antibodies or a radiolabeled antigen-binding fragment of any of the preceding antibodies.

[0054] Aspect 4. The method of any one of preceding aspects, wherein the radiolabeled anti- CD33 antibody is radiolabeled with225Ac or177Lu.

[0055] Aspect 5. The method of aspect 4, wherein the radiolabeled anti-CD33 antibody is chemically conjugated to a chelator including 1,4,5, 10-tetraazacyclododecance-l, 4, 7,10- tetracetic acid (DOTA) or a derivative thereof, and is labeled with the radionuclide225Ac or177LU by chelation of the radionuclide by the conjugated chelator.

[0056] Aspect 6. The method of any one of the preceding aspects, wherein the radiolabeled anti-CD33 antibody is225Ac-labeled and the effective amount of the225Ac-labeled antibody includes a dose of 0.1 to 10 pCi / kg subject body weight.

[0057] Aspect 7. The method of any one of the preceding aspects, wherein the radiolabeled anti-CD33 antibody is225Ac-labeled and the effective amount of the225Ac-labeled antibody includes a dose of 0.5 to 4 pCi / kg subject body weight.

[0058] Aspect 8. The method of any one of the preceding aspects, wherein the step of administering one or more of a FLT3 inhibitor, an IDH1 inhibitor, an IDH2 inhibitor, and a Menin inhibitor to the subject includes administering one or more of Sorafenib, Lestaurtinib, Midostaurin, Gilteritinib, Quizartinib, Ivosidenib, Enasidenib, Olutasidenib, Revumenib, and Ziftomenib the subject.

[0059] Aspect 9. The method of any one of the preceding aspects, wherein the step of administering to the subject an amount of a radiolabeled anti-CD33 antibody including administering to the subject a composition including a radiolabeled fraction of the anti-CD33 antibody and a non-radiolabeled fraction of the anti-CD33 antibody in a ratio of 0.1 : 1 to 1 : 1 radiolabeled to non-radiolabeled.

[0060] Aspect 10. The method of any one of the preceding aspects, wherein the step of administering to the subject an amount of a radiolabeled anti-CD33 antibody includes administering to the subject a composition including a radiolabeled fraction of the anti-CD33 antibody and a non-radiolabeled fraction of the anti-CD33 antibody in a ratio of 0.1 : 1 to 1 : 1 radiolabeled to non-radiolabeled.

[0061] Aspect 11. The method of aspect 10, wherein the amount of the anti-CD33 antibody in the composition administered (i.e., the composition recited in Aspect 10) is less than 16mg / kg of subject body weight.

[0062] Aspect 12. The method of any one of the preceding aspects, wherein the hematological malignancy is acute myeloid leukemia (AML), multiple myeloma, chronic myelogenous leukemia (CML), myelodysplastic syndrome (MDS), or a myeloproliferative neoplasm.

[0063] Aspect 13. The method of aspect of any one of the preceding aspects, wherein the hematological malignancy is a relapsed and / or refractory.

[0064] Aspect 14. The method of any one of the preceding aspects, wherein the mammalian subject is a human patient.

[0065] Aspect 15. The method of any one of the preceding aspects, wherein the hematological malignancy includes one or more gene mutations in one or more of the FLT3, IDH1, IDH2, NMP1, and / or MLL1 genes.

[0066] Aspect 16. The method of any one of the preceding aspects, further comprising administering a hypomethylating agent to the subject.

[0067] Aspect 17. The method of aspect 16, wherein the hypomethylating agent comprises azacytidine or decitabine.

[0068] Aspect 18. The method of any one of the preceding aspects, further comprising administering an antimetabolite agent to the subject.

[0069] Aspect 19. The method of aspect 18, wherein the antimetabolite agent comprises cytarabine.

[0070] Aspect 20. The method of any one of the preceding aspects, wherein the hematological malignancy is refractory or resistant to treatment with a BCL-2 inhibitor, such as refractory or resistant to treatment with venetoclax.

[0071] Aspect 21. The method of any one of the preceding aspects, wherein the method includes the step of administering to the subject an amount of a radiolabeled anti-CD33 antibody effective to kill or inhibit the proliferation of the CD33-positive malignant cells in the subject, wherein the radiolabeled anti-CD33 antibody is labeled with a radionuclide including131I,125I,123I,90Y,177LU,186Re,188Re,89Sr,153Sm,32P,225Ac,213Po,211At,212Bi,213Bi,223Ra,227I,149Tb,137Cs,212Pb,103Pd or any combination thereof.

[0072] Aspect 22. The method of aspect 21, wherein the subject has been previously treated for the hematological malignancy with gemtuzumab ozogamicin (GO).

[0073] Aspect 23. The method of aspect 20 or 21, wherein the hematological malignancy of the subject that is treated by administering the radiolabeled anti-CD33 antibody is refractory and / or resistant to treatment with gemtuzumab ozogamicin (GO).

[0074] Aspect 24. The method of any one of aspects 21-23, wherein the subject has relapsed from prior treatment of the hematological malignancy with gemtuzumab ozogamicin (GO).

[0075] Without limitation, the human dosing of 225 Ac-lintuzumab, gemtuzumab ozogamicin, and the various targeted therapies disclosed herein such as FLT3 inhibitors, menin inhibitors, and IDH inhibitors may, for example, be the same as the approved doses for such agents or the doses studied in human clinical trials of the agents. Gemtuzumab ozogamicin may, for example, be administered intravenously at a dose of 2-6 mg / m2per day such as 3 mg / m2per day, for example, on days 1, 4 and 7 of treatment. Gilteritinib may, for example, be administered orally in a daily dose of 50-200 mg, such as 100-150mg, such as 120mg, for an adult patient. Midostaurin may, for example, be administered orally once or twice daily in a dose of 10-100mg, such as 25-75mg once or twice daily, such as 50mg once or twice daily, for an adult patient. Ivosidenib may, for example, be administered orally in doses of 100-500mg daily, such as 250mg or 500mg daily. Olutasidenib may, for example, be administered orally in doses of 150 mg once daily, 150 mg twice daily, or 300 mg once daily. Enasidenib may, for example, be administered orally in doses of 50-100mg daily, such as 100 mg daily. The targeted therapy agents, such as FLT3, IDH or Menin inhibitors may, for example, be administered to a subject for at least one 1 week, at least 2 consecutive weeks, or at least consecutive 3 weeks.

[0076] Throughout this application, various patents, patent applications and other publications are cited, each of which is hereby incorporated by reference in its entirety.

[0077] While various specific embodiments have been illustrated and described herein, it will be appreciated that various changes can be made without departing from the spirit and scope of the invention(s). Moreover, features described in connection with one aspect of the invention may be used in conjunction with other aspects of the invention, even if not explicitly exemplified in combination within.

Claims

WHAT IS CLAIMED IS:

1. A method for treating a hematological malignancy comprising CD33-positive malignant cells in a mammalian subject, such as a human patient, comprising the steps of: administering to the subject one or both of(i) an amount of a radiolabeled anti-CD33 antibody effective to kill or inhibit the proliferation of the CD33-positive malignant cells in the subject, wherein the radiolabeled anti-CD33 antibody is labeled with a radionuclide comprising131I,125I,123I,90Y,177LU,186Re,188Re,89Sr,153Sm,32P,225Ac,213Po,211At,212Bi,213Bi,223Ra,227Th,149Tb,137Cs,212Pb,103Pd or any combination thereof, and(ii) an amount of an anti-CD33 antibody radioconjugate (anti-CD33 ARC), such as gemtuzumab ozogamicin (GO), effective to kill or inhibit the proliferation of the CD33- positive malignant cells in the subject; and administering one or more of a FLT3 inhibitor, an IDH1 inhibitor, an IDH2 inhibitor, and a Menin inhibitor to the subject.

2. The method of claim 1, wherein the step of administering to the subject an amount of a radiolabeled anti-CD33 antibody effective to kill or inhibit the proliferation of the CD33-positive malignant cells in the subject, is performed before the step of administering one or more of a FLT3 inhibitor, an IDH1 inhibitor, an IDH2 inhibitor, and a Menin inhibitor to the subject.

3. The method of claim 1 or 2, wherein the radiolabeled anti-CD33 antibody comprises radiolabeled lintuzumab (HuM195), radiolabeled gemtuzumab, radiolabeled vadastuximab, a radiolabeled antibody comprising the heavy chain complementarity determining regions (CDRs) and / or the light chain CDRs of any of the preceding antibodies, a radiolabeled antibody comprising the heavy chain variable region and / or the light chain variable region of any of the preceding antibodies or a radiolabeled antigen-binding fragment of any of the preceding antibodies.

4. The method of any one of preceding claims, wherein the radiolabeled anti-CD33 antibody is radiolabeled with225Ac or177Lu.

5. The method of claim 4, wherein the radiolabeled anti-CD33 antibody is chemically conjugated to a chelator comprising l,4,5,10-tetraazacyclododecance-l,4,7,10-tetracetic acid (DOTA) or a derivative thereof, and is labeled with the radionuclide225Ac or177Lu by chelation of the radionuclide by the conjugated chelator.

6. The method of any one of the preceding claims, wherein the radiolabeled anti-CD33 antibody is225Ac-labeled and the effective amount of the225Ac-labeled antibody comprises a dose of 0.1 to 10 pCi / kg subject body weight.

7. The method of any one of the preceding claims, wherein the radiolabeled anti-CD33 antibody is225Ac-labeled and the effective amount of the225Ac-labeled antibody comprises a dose of 0.5 to 4 pCi / kg subject body weight.

8. The method of any one of the preceding claims, wherein the step of administering one or more of a FLT3 inhibitor, an IDH1 inhibitor, an IDH2 inhibitor, and a Menin inhibitor to the subject comprises administering one or more of Sorafenib, Lestaurtinib, Midostaurin, Gilteritinib, Quizartinib, Ivosidenib, Enasidenib, Revumenib, and Ziftomenib the subject.

9. The method of any one of the preceding claims, wherein the step of administering to the subject an amount of a radiolabeled anti- anti-CD33 antibody comprising administering to the subject a composition comprising a radiolabeled fraction of the anti-CD33 antibody and a nonradiolabeled fraction of the anti-CD33 antibody in a ratio of 0.1 : 1 to 1 : 1 radiolabeled to nonradiolabeled.

10. The method of any one of the preceding claims, wherein the step of administering to the subject an amount of a radiolabeled anti-CD33 antibody comprises administering to the subject a composition comprising a radiolabeled fraction of the anti-CD33 antibody and a non-radiolabeled fraction of the anti-CD33 antibody in a ratio of 0.1 : 1 to 1 : 1 radiolabeled to nonradiolabeled.

11. The method of claim 10, wherein the amount of the anti-CD33 antibody in the composition administered is less than 16mg / kg of subject body weight.

12. The method of any one of the preceding claims, wherein the hematological malignancy is acute myeloid leukemia (AML), multiple myeloma, chronic myelogenous leukemia (CML), myelodysplastic syndrome (MDS), or a myeloproliferative neoplasm.

13. The method of claim of any one of the preceding claims, wherein the hematological malignancy is a relapsed and / or refractory.

14. The method of any one of the preceding claims, wherein the mammalian subject is a human patient.

15. The method of any one of the preceding claims, wherein the hematological malignancy comprises one or more gene mutations in one or more of the FLT3, IDH1, IDH2, NMP1, and / or MLL1 genes.

16. The method of any one of the preceding claims, comprising the step of administering to the subject an amount of a radiolabeled anti-CD33 antibody effective to kill or inhibit the proliferation of the CD33-positive malignant cells in the subject, wherein the radiolabeled anti-CD33 antibody is labeled with a radionuclide including131I,125I,123I,90Y,177LU,186Re,188Re,89Sr,153Sm,32P,225Ac,213Po,211At,212Bi,213Bi,223Ra, 227Th i49yb,137Cs,212Pb,103Pd or any combination thereof.

17. The method of claim 16, wherein the subject has been previously treated for the hematological malignancy with gemtuzumab ozogamicin (GO).

18. The method of claim 16 or 17, wherein the hematological malignancy of the subject that is treated by administering the radiolabeled anti-CD33 antibody is refractory and / or resistant to treatment with gemtuzumab ozogamicin (GO).

19. The method of any one of claims 16-18, wherein the subject has relapsed from prior treatment of the hematological malignancy with gemtuzumab ozogamicin (GO).

20. The method of any one of the preceding claims wherein the hematological malignancy is AML.

21. The method of claim 20, wherein the AML is relapsed and / or refractory AML.

Images