Anti-ilt7 binding agents for the treatment and prevention of myositis

Abstract

The present disclosure is related to compositions and methods of treating diseases (e.g., myositis diseases and disorders) in a subject in need thereof using anti-ILT7 antibodies or antigen-binding fragments thereof.

Description

ANTLILT7 BINDING AGENTS FOR THE TREATMENT AND PREVENTION OFMYOSITISCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Application No. 63 / 387,023, filed December 12, 2022, the contents of which are incorporated by reference herein in its entirety for all purposes.REFERENCE TO AN ELECTRONIC SEQUENCE LISTING

[0002] The contents of the electronic sequence listing (HOPA_062_01WO_SeqList_ST26.xml; Size: 10,663 bytes; and Date of Creation: December 4, 2023) are herein incorporated by reference in its entirety.TECHNICAL FIELD

[0003] The present disclosure is related to compositions comprising ILT7 binding proteins and methods of using the same in the treatment and prevention of myositis.BACKGROUND

[0004] Idiopathic inflammatory myopathies can result in permanent muscle damage with weakness if not controlled promptly. Currently, corticosteroids, intravenous immunoglobulin (IVIG), and other immune modulators are used for treatment, but these medications are also associated with side effects including risk for diabetes, osteoporosis, cataracts, opportunistic infections, and thrombosis. In addition, some subjects do not achieve timely control of their disease with these therapies. This, together with the burden of their side effects, yields the clinical need for a therapy to treat these patients.

[0005] Immunoglobulin-like transcript-7 (ILT7) can be targeted for treatment and prevention of myopathies. Therefore, provided are compositions and methods of utilizing anti-ILT7 antibodies or antigen-binding fragments thereof to reduce or eliminate symptoms or diseases associated with ILT7.BRIEF SUMMARY

[0006] Provided are methods of treating dermatomyositis, comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigenbinding fragment thereof to a subject in need thereof, wherein the ILT7 antibody or antigen-binding fragment thereof comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg, and wherein the antibody is administered once every 4 weeks. In aspects, the dermatomyositis comprises definite myositis. In aspects, the dermatomyositis comprises probable myositis.

[0007] Provided are methods of treating anti -synthetase inflammatory myositis (ASIM), the methods comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigen-binding fragment thereof to a subject in need thereof, wherein the ILT7 antibody comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg, and wherein the antibody is administered once every 4 weeks. In aspects, the ASIM comprises definite myositis. In aspects, the ASIM comprises probable myositis.

[0008] Provided are methods of treating a disease, the methods comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigenbinding fragment thereof to a subject in need thereof, wherein the ILT7 antibody comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount comprises a dosage from about 300 mg, and wherein the administering is completed once every 4 weeks.

[0009] Provided are methods of treating a disease, the method comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigenbinding fragment thereof to a subject in need thereof, wherein the ILT7 antibody comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, and wherein the administration is effective in reducing disease as compared to: (a) disease in an otherwise comparable subject lacking the administering; or (b) a baseline measurement of disease in the subject in need thereof.

[0010] In aspects, the administering is continued for at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or up to about 15 administrations. In aspects, the administering is effective in reducing disease as compared to (b) the baseline measurement of disease in the subject in need thereof, and wherein the reduction is determined by detecting a reduced total improvement score in the subject. In aspects, the administering is effective in reducing disease as compared to (b) the baseline measurement of disease in the subject in need thereof, and wherein the reduction is determined by detecting a reduced level of a symptom of the disease in the subject. In aspects, the determination is completed after 6 and / or 12 administrations. In aspects, the total improvement score is > 10, 20, 30, 40, or 50. In aspects, the total improvement score is > 20. In aspects, the total improvement score is > 40. In aspects, the reduced level of the symptom comprises a reduction in a score of an assessment, as compared to baseline, selected from the group consisting of: Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI), Myositis Disease Activity Assessment Tool (MDAAT), myositis damage index (MDI), and combinations thereof. In aspects, the reduced level of the symptom comprises an increase in lung compliance as determined by an increase in forced vital capacity (FVC) as compared to baseline. In aspects, the administering is effective in reducing disease as compared to (b) the baseline measurement of disease in the subject in need thereof, and wherein the reduction is determined by a decrease in use of a corticosteroid, and wherein the determination is completed after 6 administrations. In aspects, the corticosteroid comprises prednisone. In aspects, the decrease comprises a reduction in frequency of use at least about 10%, 15%, 20%, 25%, 30%, or 40%. In aspects, the decrease is from about a > 10 mg / day dosage to a 7.5 mg / day dosage. In aspects, the ILT7 antibody comprises a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH and the VL regions comprise an amino acid sequence at least 80% identical to SEQ ID NO: 2 and SEQ ID NO: 7, respectively. In aspects, the ILT7 antibody comprises a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH and the VL regions comprise the amino acid sequence of SEQ ID NO: 2 and SEQ ID NO: 7, respectively. In aspects, the ILT7 antibody is a monoclonal antibody. In aspects, the ILT7 antibody is afucosylated. In aspects, a sample of the subject in need is positive for one or more ASIM-associated antibodies. In aspects, the one or more ASIM-associated antibodies is selected from the group consisting of: anti-Jo-1, anti-PL-12, anti -PL-7, anti-KS, anti-EJ, anti-OJ, anti-ZO, and anti-YRS(HA). In aspects, the subject in need thereof has a dermatomyositis-related rash. In aspects, the disease is effectuated byplasmacytoid dendritic cells. In aspects, the administration is effective in reducing a level of a type I interferon in the subject as compared to a baseline level of the subject. In aspects, the level is reduced by at least about 1-fold, 5-fold, 10-fold, 25-fold, 50-fold, 75-fold, 100- fold, 150-fold, or 250-fold. In aspects, the administering is effective in eliminating the disease for at least about 3 months, 6 months, 1 year, or 2 years. In aspects, the administering is subcutaneous.

[0011] Provided are methods of treating dermatomyositis, the methods comprising subcutaneously administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigen-binding fragment thereof to a subject in need thereof, wherein the ILT7 antibody or antigen-binding fragment thereof comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg.

[0012] Provided are methods of treating anti -synthetase inflammatory myositis (ASIM), the method comprising subcutaneously administering an effective amount of an anti- Immunoglobulin-like transcript-7 (ILT7) antibody or antigen-binding fragment thereof to a subject in need thereof, wherein the ILT7 antibody comprises Complementarity- Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg.

[0013] These and other aspects are described below.BRIEF DESCRIPTION OF THE FIGURES

[0014] The accompanying figures, which are incorporated herein and form a part of the specification, illustrate some, but not the only or exclusive, example aspects and / or features. It is intended that the aspects and figures disclosed herein are to be considered illustrative rather than limiting.

[0015] FIG. 1 shows an exemplary study flow diagram.DETAILED DESCRIPTION

[0016] The present disclosure provides antibodies and antigen-binding fragments thereof which bind to Immunoglobulin-like transcript-7 (ILT7). Inhibition of binding can reduce oreliminate activation of inflammatory signaling pathways associated with related disease. In aspects, anti-ILT7 antibodies and antigen-binding fragments disclosed herein can be used to neutralize ILT7. In aspects, anti-ILT7 antibodies and antigen-binding fragments disclosed herein can be used to regulate pDC activity. In aspects, anti-ILT7 antibodies and antigenbinding fragments disclosed herein can be used to regulate IFN release. In aspects, anti- ILT7 antibodies and antigen-binding fragments disclosed herein can be used to reduce or eliminate ILT7 / BST2 binding. Such an approach is advantageous as it attacks the inflammation at the signaling source, allowing for a more robust anti-inflammatory treatment effect of diseases. Provided are polynucleotides encoding anti-ILT7 antibodies and antigen-binding fragments, encoded polypeptides, and pharmaceutical compositions comprising the same. Also disclosed herein are methods of using the anti-ILT7 antibodies and antigen-binding fragments thereof in methods of treating disease. In aspects, the anti- ILT7 antibodies and antigen-binding fragments thereof are used in methods of treating dermatomyositis (DM) and / or anti -synthetase inflammatory myositis (ASIM).Definitions

[0017] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the subject matter pertains. All publications, patent applications, patents, and other references mentioned herein are expressly incorporated by reference in their entirety. In cases of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples described herein are illustrative only and are not intended to be limiting.

[0018] As used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.

[0019] The term “about” or “approximately” when immediately preceding a numerical value means a range (e.g., plus or minus 10% of that value). For example, “about 50” can mean 45 to 55, “about 25,000” can mean 22,500 to 27,500, etc., unless the context of the disclosure indicates otherwise, or is inconsistent with such an interpretation. For example, in a list of numerical values such as “about 49, about 50, about 55, . . .”, “about 50” means a range extending to less than half the interval(s) between the preceding and subsequent values, e.g., more than 49.5 to less than 52.5. Furthermore, the phrases “less than about” a value or “greater than about” a value should be understood in view of the definition of the term “about” provided herein. Similarly, the term “about” when preceding a series ofnumerical values or a range of values (e.g., “about 10, 20, 30” or “about 10-30”) refers, respectively to all values in the series, or the endpoints of the range.

[0020] As used herein, the term “subject” refers to any subject, e.g., a human or a nonhuman mammal, for whom diagnosis, prognosis, or therapy is desired. The term “subject” may mean a human or non-human mammal affected, likely to be affected, or suspected to be affected with a disease. The terms “subject” and “subject” are used interchangeably herein. In aspects, the subject is a mammal. A mammal includes primates, such as humans, monkeys, chimpanzee, and apes, and non-primates such as domestic animals, including laboratory animals (such as rabbits and rodents, e.g., guinea pig, rat, or mouse) and household pets and farm animals (e.g., cats, dogs, swine, cattle, sheep, goats, horses, rabbits), and non-domestic animals, such as wildlife, birds, reptile, fish, or the like.

[0021] As used herein, the term “a subject in need thereof’ includes subjects that could or would benefit from the methods described herein. Subjects in need of treatment include, without limitation, those already with the condition or disorder, those prone to having the condition or disorder, those in which the condition or disorder is suspected, as well as those in which the condition or disorder is to be prevented, ameliorated, or reversed.

[0022] As used herein, “treating” or “treat” describes the management and care of a subject for the purpose of combating a disease, condition, or disorder and includes the administration of an anti-ILT7 antibody or antigen-binding fragment thereof used in the methods described herein to alleviate the symptoms or complications of a disease, condition or disorder, or to eliminate the disease, condition or disorder. Thus, the term “treat” or “treating” refers to both therapeutic measures and prophylactic or preventative measures, wherein the objective is to prevent, slow down (lessen), or ameliorate the progression of a disease (e.g., a myositis disease or disorder). Beneficial or desired clinical results include, but are not limited to, alleviation of symptoms, diminishing the extent of the disease, stabilized (i.e., not worsening) state of the disease, delaying or slowing of disease progression, amelioration or palliation of the disease state, and reversing the disease (whether partial or total). The term “treat” can also include treatment of a cell in vitro or an animal model.

[0023] When referring to a nucleic acid sequence or protein sequence, the term “identity” is used to denote similarity between two sequences. Unless otherwise indicated, percent identities described herein are determined using the BLAST algorithm available at the world wide web address: blast.ncbi.nlm.nih.gov / Blast.cgi using default parameters.IMMUNOGLOBULIN-LIKE TRANSCRIPT-7 (ILT7) BINDING PROTEINS

[0024] Plasmacytoid dendritic cells (pDCs) are important regulators of the immune system and the main source of Type-I interferon (IFN, e.g., IFN-a). IFN-a is a key cytokine in the innate response that enhances activation of all arms of the immune system. pDCs release IFN in response to nucleic acids that are sensed by Toll-like receptors (TLRs) TLR7 and TLR9 expressed on the surface of the pDCs. The TLR-induced response is regulated by receptors containing immunoreceptor tyrosine-based activation motifs (ITAMs). Immunoglobulin-like transcript-7 (ILT7), also called LIRA4, LILRA4, or CD85g, is one such receptor. ILT7 contains four immunoglobulin-like extracellular domains and a transmembrane domain. The extracellular portion is important for interacting with the ILT7 ligand, bone marrow stromal cell antigen 2 (BST2), and the transmembrane domain of ILT7 contains a positively charged residue that allows it to complex with FcsRIy. The BST2-ILT7 interaction negatively regulates the innate immune function of pDCs, where in vitro antibody cross-linking of ILT7 has been shown to negatively regulate the production of IFN- a and TNF-a by pDCs.

[0025] Provided herein are compositions that bind ILT7. In aspects, provided compositions comprise ILT7 antagonists. In aspects, provided compositions bind to and neutralize the activity of ILT7. In aspects, provided compositions comprise an Immunoglobulin G (IgG) human monoclonal antibody (mAb). In aspects, provided herein are compositions that bind ILT7 and have antibody dependent cellular cytotoxicity (ADCC) activity. In aspects, provided herein are compositions that comprise an anti-ILT7 antibody or antigen-binding fragment thereof.

[0026] In aspects, an anti-ILT7 antibody comprises an antibody that binds to ILT7. Binding of ILT7 can be effectuated by any portion of an antibody. In aspects, an antibody or antigenbinding fragment binds ILT7 by way of a complementary determining region (CDR). In aspects, an antibody binds ILT7 by way of VL and / or VH chains. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof comprises six complementarity-determining regions (CDRs) designated heavy CDR1 (HCDR1), HCDR2, HCDR3, light CDR1 (LCDR1), LCDR2, and LCDR3. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof comprises two light chain variable loop domains (VL) and two heavy chain variable loop domains (VH). Basic antibody structures in vertebrate systems are relatively well understood. See, e.g., Harlow et al., Antibodies: A Laboratory Manual, (Cold Spring Harbor Laboratory Press, 2nd ed., 1988). Antibodies or antigen-binding fragments, variants,or derivatives thereof include, but are not limited to, polyclonal, monoclonal, human, humanized, or chimeric, antibodies, epitope-binding fragments (e.g., Fab, F(ab')2, Fv, single-chain Fvs (scFv), single-chain antibodies, disulfide-linked Fvs (sdFv), fragments comprising either a VL or VH domain (Fd), fragments produced by a Fab expression library, and other antibody fragments and combinations thereof that retain antigen-binding function, i.e., the ability to bind, for example, ILT7.

[0027] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof comprises a VL domain and a VH domain, where the VH domain comprises the polypeptide of SEQ ID NO: 2 and the VL domain comprises the polypeptide of SEQ ID NO: 7. In aspects, an anti- ILT7 antibody comprises two VL domains and two VH domains, where the VH domain comprises the polypeptide of SEQ ID NO: 2 and the VL domain comprises the polypeptide of SEQ ID NO: 7. In aspects, the nucleic acid sequences of the VH and VL domains comprise or consist of nucleic acid SEQ ID NO: 1 and nucleic acid SEQ ID NO: 6, respectively.

[0028] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof comprises six CDR regions designated HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1 comprises the amino acid of SEQ ID NO: 3, the HCDR2 comprises the amino acid of SEQ ID NO: 4, the HCDR3 comprises the amino acid of SEQ ID NO: 5, the LCDR1 comprises the amino acid of SEQ ID NO: 8, the LCDR2 comprises the amino acid of SEQ ID NO: 9, and the LCDR3 comprises the amino acid of SEQ ID NO: 10.

[0029] Exemplary sequences for anti-ILT7 antibodies and antigen-binding fragments thereof are shown in Table 1. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof comprises at least or at most about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or up to about 100% identity with any one of SEQ ID NO: 1 - SEQ ID NO: 10 shown in Table 1. In aspects, any one of the sequences from Table 1 can be modified. In aspects, a modification comprises one or more truncations, deletions, insertions, and combinations thereof. A modification can occur at any of the residues provided in Table 1 and in any number of residues from Table 1. In aspects, a modification can comprise from 1-3, 1-5, 1-10, 1-20, 3-8, 3-10, 3-15, 5-8, 5-10, or 5-20 residues. In aspects, a modification can occur in up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, or up to about 300 residues.Table 1. Exemplary sequences for an ILT7 binding protein.

[0030] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof of the disclosure can comprise variants of the sequences provided they retain the ability to bind ILT7. For example, conservative amino acid substitutions can be made within any one of the disclosed CDRs. Various alterations can be made according to the methods described in Antibody Engineering, 2nd ed., Oxford University Press, ed. Borrebaeck, 1995. These alterations comprise but are not limited to nucleotide sequences that are altered by the substitution of different codons that encode a functionally equivalent amino acid residue within the sequence, thus producing a “silent” change. For example, the nonpolar amino acids comprise alanine (A), leucine (L), isoleucine (I), valine (V), proline (P), phenylalanine(F), tryptophan (W), and methionine (M). The polar neutral amino acids comprise glycine(G), serine (S), threonine (T), cysteine (C), tyrosine (Y), asparagine (N), and glutamine (Q). The positively charged (basic) amino acids comprise arginine (R), lysine (K), and histidine(H). The negatively charged (acidic) amino acids comprise aspartic acid (D) and glutamicacid (E). In aspects, the CDR amino acid sequences disclosed herein (SEQ ID NOs: 3-5, 8- 10) can vary by at least about 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or up to about 100%.

[0031] Derivatives and analogs of antibodies or antigen-binding fragments thereof of the disclosure can be produced by various techniques, including recombinant and synthetic methods (Maniatis (1990) Molecular Cloning, A Laboratory Manual, 2nd ed., Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., and Bodansky et al. (1995) The Practice of Peptide Synthesis, 2nd ed., Spring Verlag, Berlin, Germany). In aspects, a method for making a VH domain which is an amino acid sequence variant of a VH domain of the disclosure comprises a step of adding, deleting, substituting, or inserting one or more amino acids in the amino acid sequence of the presently disclosed VH domain, optionally combining the VH domain thus provided with one or more VL domains, and testing the VH domain or VH / VL combination or combinations for specific binding to the antigen. An analogous method can be employed in which one or more sequence variants of a VL domain disclosed herein are combined with one or more VH domains. In aspects, the amino acid and / or nucleic acid VH or VL sequence disclosed herein (SEQ ID NOs: 1, 2, 6, and 7) can vary by at least about 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or up to about 100%.

[0032] The present disclosure provides methods for the use of Immunoglobulin-like transcript-7 (ILT7) binding molecules, e.g., antibodies and antigen-binding fragments thereof which bind ILT7. The full-length amino acid and nucleotide sequences for ILT7 are known in the art (see, e.g., UniProt Acc. No. P59901 for human ILT7). The ILT7-specific antibodies or antigen-binding fragments of the present disclosure inhibit BST2-mediated activation of ILT7 and thereby decrease proinflammatory signaling and reduce inflammation in a subject. In aspects, an anti-ILT7 antibody is also known as HZN-7734. In aspects, an anti-ILT7 antibody is also known as MEDI7734. In aspects, an anti-ILT7 antibody is also known as VIB7734. In aspects, an anti-ILT7 antibody is also known as Daxdilimab. In aspects, compositions of the disclosure may comprise any of the amino acid or nucleic acid sequences as described in U.S. Patent No. 11,072,652, which are incorporated herein by reference in their entireties. In aspects, provided compositions may comprise any of the sequences as shown in Table 1.

[0033] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof disclosed herein can be glycosylated. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof can have a glycosylation pattern that differs from the wild-type pattern. For example,one or more carbohydrate moieties can be deleted and / or one or more glycosylation sites added. Addition of glycosylation sites to the presently disclosed antibodies or antigenbinding fragments can be accomplished by altering the amino acid sequence to contain glycosylation site consensus sequences known in the art. Another means of increasing the number of carbohydrate moieties on the antibody or antigen-binding fragment is by chemical or enzymatic coupling of glycosides to the amino acid residues of the antibody or antigen-binding fragment. Such methods are described in WO 87 / 05330, and in Aplin et al. (1981) CRC Crit. Rev. Biochem., 22: 259-306. Removal of any carbohydrate moieties from the antibodies or antigen-binding fragments may be accomplished chemically or enzymatically, for example, as described by Hakimuddin et al. (1987) Arch. Biochem. Biophys., 259: 52; and Edge et al. (1981) Anal. Biochem., 118: 131 and by Thotakura et al. (1987) Meth. Enzymol., 138: 350.

[0034] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof disclosed herein can be afucosylated. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof can have a fucosylation pattern that differs from the wild-type pattern. For example, one or more fucose moieties can be deleted. Deletion of fucosylation sites to the presently disclosed antibodies or antigen-binding fragments can be accomplished by altering the amino acid sequence to remove fucosylation site consensus sequences known in the art. Another means of removal of any fucose moieties from the antibodies or antigen-binding fragments may be accomplished chemically or enzymatically, for example, as described by Hakimuddin et al. (1987) Arch. Biochem. Biophys., 259: 52; and Edge et al. (1981) Anal. Biochem., 118: 131 and by Thotakura et al. (1987) Meth. Enzymol., 138: 350. Additional means of generating afucosylated antibodies can comprise use of cell lines, such as the GDP- keto-6-deoxymannose 3,5-epimerase / 4 reductase (FX)-knockout CHO cell line that produces antibodies with afucosylated N-glycans. Other cell lines that can be employed comprise YB2 / 0 cells which have reduced levels of the Fut8 mRNA. Additional means of generating afucosylated antibodies are described in Pereira NA, Chan KF, Lin PC, Song Z. The "less-is-more" in therapeutic antibodies: Afucosylated anti-cancer antibodies with enhanced antibody-dependent cellular cytotoxicity. MAbs. 2018 Jul;10(5):693-711, which is incorporated by reference herein in its entirety.

[0035] In aspects, an anti-ILT7 antibody or antigen-binding fragment can be tagged. In aspects, an anti-ILT7 antibody or antigen-binding fragment can be tagged with a functional agent. In aspects, a functional agent is an imaging agent (e.g., a radionuclide, a biotin, afluorescent molecule, a luminescent molecule, or a non-radioactive paramagnetic metal ion). In aspects, a functional agent is an enzyme (e.g., horseradish peroxidase, alkaline phosphatase, P-galactosidase, or acetylcholinesterase). In aspects, a functional agent is a drug (e.g., a cytotoxic agent or a radioactive compound).Dosing

[0036] In aspects, any of the compositions of the disclosure comprising an anti-ILT7 antibody or antigen-binding fragment thereof can be administered in any form. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered intravenously, subcutaneously, orally, intramuscularly, intrathecally, sublingually, rectally, vaginally, cutaneously, systemically, topically, transdermally, or by way of inhalation. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered subcutaneously.

[0037] An anti-ILT7 antibody or antigen-binding fragment thereof of the disclosure can be administered at any dose. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose from about: 50 mg, 75 mg, 100 mg, 125 mg, 150 mg, 175 mg, 200 mg, 225 mg, 250 mg, 275 mg, 300 mg, 325 mg, 350 mg, 375 mg, 400 mg, 425 mg, 450 mg, 475 mg, 500 mg, 525 mg, 550 mg, 575 mg, 600 mg, 650 mg, 700 mg, 750 mg, 800 mg, 850 mg, 900 mg, 950 mg, 1000 mg, 1050 mg, 1100 mg, 1150 mg, 1200 mg, 1250 mg, 1300 mg, 1350 mg, 1400 mg, 1450 mg, or about 1500 mg. Any of the aforementioned dosages may be effective dosages for a method comprising prevention, reduction, or elimination.

[0038] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose of between about: 50-100 mg, 50-150 mg, 100-200 mg, 130-180 mg, 150-250 mg, 200-300 mg, 250-350 mg, 50-1500 mg, 75-1200 mg, 100-800 mg, or 150-500 mg. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose selected from the group consisting of: 150 mg, 175 mg, 200 mg, 225 mg, 250 mg, 275 mg, 300 mg, 325 mg, 350 mg, 375 mg, 400 mg, 425 mg, 450 mg, 500 mg, 525 mg, 550 mg, 575 mg, and 600 mg. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at an effective dose of about 150 mg. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at an effective dose of about 200 mg. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at an effective dose of about 300 mg.Dosing Frequency

[0039] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof of the disclosure is administered on a schedule that provides optimal results. In aspects, an anti- ILT7 antibody or antigen-binding fragment thereof disclosed herein is administered to a subject in need thereof about once a week, about twice a week, about every two weeks, about every four weeks, about once a month, about every six weeks, about every two months, about every 3 months, about every 12 weeks, about every fifteen weeks, about every sixteen weeks, about every four months, about every five months, about every six months, or semiannually.

[0040] Any number of administrations may be provided to a subject in need thereof. In aspects, a subject is administered an effective dose daily, weekly, biweekly, or up to about the lifetime of the subject. In aspects, administration are given for up to about 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 1 year, 2 years, 3 years, 4 years, or 5 years. In aspects, a subject receives an effective dose on Day 1, Day 28, Day 56, Day 84, Day 112, Day 140, Day 168, Day 196, Day 224, Day 252, Day 280, and Day 308 post treatment initiation. In aspects, a subject receives an effective dose on week 0, week 4, week 8, week 12, week 16, week 20, week 24, week 28, week 32, week 36, week 40, and week 44 post treatment initiation. In aspects, a subject receives an effective dose of 300 mg of an anti-ILT7 antibody or antigen-binding fragment thereof on Day 1, Day 28, Day 56, Day 84, Day 112, Day 140, Day 168, Day 196, Day 224, Day 252, Day 280, and Day 308 post treatment initiation. In aspects, a subject in need thereof is administered an effective dose of 300 mg of an anti-ILT7 antibody or antigen-binding fragment thereof on week 0, week 4, week 8, week 12, week 16, week 20, week 24, week 28, week 32, week 36, week 40, and week 44 post treatment initiation. In aspects, a subject in need thereof is administered an effective dose of 300 mg of an anti- ILT7 antibody or antigen-binding fragment thereof on Day 1 and then every 4 weeks thereafter as needed. In aspects, a subject in need thereof is administered 300 mg of an anti- ILT7 antibody or antigen-binding fragment thereof every four weeks. Any of the aforementioned administrations can deviate by about 0-7 days, 0-5 days, 0-4 days, 0-3 days, 0-2 days, or by about 3 days.

[0041] In aspects, a subject receives an effective dose of an anti-ILT7 antibody or antigenbinding fragment thereof on Day 1, Day 28 (± 3 day), Day 56 (± 3 days), Day 84 (± 3 days),Day 112 (± 3 days), Day 140 (± 3 days), Day 168 (± 3 days), Day 196 (± 3 days), Day 224 (± 3 days), Day 252 (± 3 days), Day 280 (± 3 days), and Day 308 (± 3 days) post treatment initiation.

[0042] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at an effective single dose. In aspects, a subject in need thereof is administered at least two administrations of an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered as a series of multiple doses. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at an effective single dose or multiple doses.

[0043] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose of about 300 mg for at least 1 dose and is administered about once a month or every four weeks thereafter. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered as two doses of about 150 mg for at least 2 doses and is administered at 2 doses about once a month thereafter. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose of about 300 mg once about every four weeks, once about every month, once about every two months, or once about every three months. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at two doses of about 150 mg about every four weeks, about every month, twice about every two months, or twice about every three months.

[0044] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered for two or more doses. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof of the disclosure is administered to a subject in need thereof until myositis is prevented, reduced, or eliminated as determined by a test of the disclosure. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered as an effective dose of about 300 mg. In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof is administered at an effective dose of about 300 mg subcutaneously. In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof is administered as two doses of about 150 mg each subcutaneously. In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen-bindingfragment thereof is administered as two doses of about 150 mg each every 4 weeks subcutaneously. In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof is administered as two doses of about 150 mg each every 4 weeks for at least 12 administrations subcutaneously. In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of: SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively. In aspects, a method disclosed herein comprises administration of an antibody or antigenbinding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of: SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, and wherein the antibody or antigen-binding fragment thereof is administered as a dose of 300 mg or as two doses of about 150 mg each subcutaneously. In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of: SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, and wherein the antibody or antigen-binding fragment thereof is administered as a dose of 300 mg or as two doses of about 150 mg each subcutaneously every 4 weeks. In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of: SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, and wherein the antibody or antigen-binding fragment thereof is administered as a dose of 300 mg or as two doses of about 150 mg each subcutaneously every 4 weeks for at least 12 administrations.

[0045] In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof in any of theaspects or methods disclosed herein, wherein the antibody or antigen-binding fragment thereof comprise VH and VL, wherein the VH and VL comprise an amino acid sequence having at least about 80%, 85%, 90%, 95%, 99%, or 100% identity to SEQ ID NOs: 2 and 7, respectively. In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof comprise VH and VL, wherein the VH and VL comprise the amino acid sequences of: SEQ ID NOs: 2 and 7, respectively, and wherein the antibody or antigen-binding fragment thereof is administered as a dose of about 300 mg or as two doses of about 150 mg each. In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen -binding fragment thereof comprise VH and VL, wherein the VH and VL comprise the amino acid sequences of: SEQ ID NOs: 2 and 7, respectively, and wherein the antibody or antigen-binding fragment thereof is administered as a dose of about 300 mg or as two doses of about 150 mg each subcutaneously. In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof comprise VH and VL, wherein the VH and VL comprise the amino acid sequences of: SEQ ID NOs: 2 and 7, respectively, and wherein the antibody or antigen-binding fragment thereof is administered as a dose of about 300 mg subcutaneously every 4 weeks. In aspects, a method disclosed herein comprises administration of an antibody or antigen-binding fragment thereof that binds ILT7 to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof comprise VH and VL, wherein the VH and VL comprise the amino acid sequences of: SEQ ID NOs: 2 and 7, respectively, and wherein the antibody or antigen-binding fragment thereof is administered as a dose of about 300 mg subcutaneously every 4 weeks.

[0046] In aspects, a subject in need thereof is administered an effective dose of an anti-ILT7 antibody or antigen-binding fragment thereof once about every 2-4 weeks. In aspects, a subject in need thereof is administered an effective dose of an anti-ILT7 antibody or antigenbinding fragment thereof once every 4 weeks. In aspects, a subject in need thereof is administered 300 mg of an anti-ILT7 antibody or antigen-binding fragment thereof once every 4 weeks for at least 3 doses, once every 4 weeks for at least 4 doses, once every 4 weeks for at least 5 doses, or a combination thereof. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at an effective dose of about 300 mg onceevery four weeks. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at an effective dose of about 300 mg every month. In aspects, a subject in need thereof is administered two 150 mg doses of an anti-ILT7 antibody or antigen-binding fragment thereof once every 4 weeks for at least 3 doses, once every 4 weeks for at least 4 doses, once every 4 weeks for at least 5 doses, or a combination thereof. In aspects, an anti- ILT7 antibody or antigen-binding fragment thereof is administered as two 150 mg doses every four weeks or every month.METHODS

[0047] In aspects herein, methods are directed to treat, reduce, or eliminate a myositis disease or disorder. In aspects, a method comprises administering an anti-ILT7 antibody or antigen-binding fragment thereof of the disclosure. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered to prevent, reduce, or eliminate myositis in a subject in need thereof using any of the dosing schedules disclosed herein. Idiopathic inflammatory myopathies (IIMs), such as myositis, can be classified into several subgroups: dermatomyositis (including amyopathic dermatomyositis), anti synthetase inflammatory myositis (ASIM), immune-mediated necrotizing myopathy, inclusion body myositis, polymyositis, and overlap myositis. In aspects, a myositis disease or disorder comprises dermatomyositis (DM). In aspects, a myositis disease or disorder comprises anti -synthetase inflammatory myositis (ASIM). In aspects, a myositis disease or disorder comprises polymyositis (PM). In aspects, a myositis disease or disorder comprises sporadic inclusion body myositis (sIBM).

[0048] In aspects, a subject with DM has DM with definite or probable myositis. In aspects, a subject with DM has a DM rash. In aspects, a subject with ASIM has ASIM with definite or probable myositis. In aspects, a subject with ASIM has a positive ASIM associated antibody. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered to prevent, reduce, or eliminate DM in a subject in need thereof using any of the dosing schedules disclosed herein. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered to prevent, reduce, or eliminate ASIM in a subject in need thereof using any of the dosing schedules disclosed herein. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered to prevent, reduce, or eliminate disease in a subject that tests positive for anti-histidyl tRNA synthetase (e.g., anti-Jo-1) antibodies prior to treatment. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered to prevent, reduce, or eliminate disease in a subject that has an ASIM diagnosisand tests positive for anti-histidyl tRNA synthetase (e.g., anti-Jo-1) antibodies prior to treatment. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered to prevent, reduce, or eliminate disease in a subject that has an ASIM diagnosis and a positive ASIM associated antibody. In aspects, an anti-ILT7 antibody or antigenbinding fragment thereof is administered to prevent, reduce, or eliminate disease in a subject has historically tested positive for one or more of anti-alanyl (e.g., anti-PL-12), anti-threonyl (e.g., anti-PL-7), anti-asparaginyl (e.g., anti-KS), anti-glycyl (e.g., anti-EJ), anti -isoleucyl (e.g., anti-OJ), anti-phenylalanyl tRNA synthetase (e.g., anti-ZO), or anti-tyrosil (e.g., anti- YRS(HA)) antibodies. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered to prevent, reduce, or eliminate disease in a subject that has an ASIM diagnosis and has historically tested positive for one or more of anti-alanyl (e.g., anti-PL- 12), anti-threonyl (e.g., anti-PL-7), anti-asparaginyl (e.g., anti-KS), anti-glycyl (e.g., anti- EJ), anti-isoleucyl (e.g., anti-OJ), anti-phenylalanyl tRNA synthetase (e.g., anti-ZO), or anti- tyrosil (e.g., anti-YRS(HA)) antibodies.

[0049] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered to prevent, reduce, or eliminate disease in a subject wherein the subject is not diagnosed with a disease. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered to prevent, reduce, or eliminate disease in a subject wherein the subject is not diagnosed with immune-mediate necrotizing myopathy (IMNM), inclusion body myositis (IBM), or drug-induced myositis. In aspects, a subject is diagnosed with IMNM if the subject has 3 -hydroxy-3 -methylglutaryl -coenzyme A reductase (i.e., anti- HMGR) antibodies, anti-signal recognition particle (i.e., anti-SRP) antibodies, or is autoantibody negative. In aspects, a subject is diagnosed with IBM if the subject has anti- cytosolic 5 ’-nucleotidase 1A (i.e., anti-CNIA) antibodies.

[0050] In aspects, a method of treating a subject in need thereof comprises administering an effective amount of an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, an administration is effective in reducing a disease or a disorder as compared to: a) the disease or disorder in an otherwise comparable subject lacking the administration; or b) a baseline measurement of the disease or disorder in the subject in need thereof. In aspects, an administration is effective in reducing a level of a type I interferon (IFN, e.g., IFN-a) in a subject in need thereof as compared to a baseline level of the subject. In aspects, a level of a type I IFN is reduced in a subject administered an anti-ILT7 antibody or antigen-bindingfragment by at least about or at most about: 1-fold, 5-fold, 10-fold, 25-fold, 50-fold, 75-fold, 100-fold, 150-fold, or 250-fold as compared to a baseline level of the subject.

[0051] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is used to treat a myositis disease or disorder. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is used to treat a subject in need thereof using any of the dosing schedules disclosed herein.

[0052] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose of about 300 mg. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose of about 150 mg twice. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose of about 300 mg subcutaneously. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose of about 150 mg twice via subcutaneous administration. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose of about 300 mg every 4 weeks. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose of about 150 mg twice every 4 weeks. In aspects, an anti- ILT7 antibody or antigen-binding fragment thereof is administered at a dose of about 150 mg twice every 4 weeks for at least 2 doses. In aspects, an anti-ILT7 antibody or antigenbinding fragment thereof is administered at a dose of about 150 mg twice every 4 weeks for at least 3 doses. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose of about 300 mg via subcutaneous administration every 4 weeks for at least 2 doses. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered at a dose of about 300 mg via subcutaneous administration every 4 weeks for at least 3 doses.

[0053] In aspects, a composition comprising an anti-ILT7 antibody or antigen-binding fragment is formulated for administration. In aspects, an anti-ILT7 antibody or antigenbinding fragment thereof is formulated at a concentration of at least about or at most about: 1 mg / mL, 2 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, 7 mg / mL, 8 mg / mL, 9 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, 35 mg / mL, 40 mg / mL, 45 mg / mL, 50 mg / mL, 55 mg / mL, 60 mg / mL, 65 mg / mL, 70 mg / mL, 75 mg / mL, 80 mg / mL, 85 mg / mL, 90 mg / mL, 95 mg / mL, 100 mg / mL, 105 mg / mL, 110 mg / mL, 115 mg / mL, 120 mg / mL, 125 mg / mL, 130 mg / mL, 135 mg / mL, 140 mg / mL, 145 mg / mL, 150 mg / mL, 155 mg / mL, 160 mg / mL, 165 mg / mL, 170 mg / mL, 175 mg / mL, 180 mg / mL, 185 mg / mL, 190 mg / mL, 195 mg / mL, 200 mg / mL, 205 mg / mL, 210 mg / mL, 215 mg / mL, 220 mg / mL, 225 mg / mL, 230mg / mL, 235 mg / mL, 240 mg / mL, 245 mg / mL, 250 mg / mL, 255 mg / mL, 260 mg / mL, 265 mg / mL, 270 mg / mL, 275 mg / mL, 280 mg / mL, 285 mg / mL, 290 mg / mL, 295 mg / mL, 300 mg / mL, 305 mg / mL, 310 mg / mL, 315 mg / mL, 320 mg / mL, 325 mg / mL, 330 mg / mL, 335 mg / mL, 340 mg / mL, 345 mg / mL, 350 mg / mL, 355 mg / mL, 360 mg / mL, 365 mg / mL, 370 mg / mL, 375 mg / mL, 380 mg / mL, 385 mg / mL, 390 mg / mL, 395 mg / mL, or up to about 400 mg / mL. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof effective dose may be formulated at a concentration of about 100 mg / mL. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof effective dose may be formulated at a concentration of about 150 mg / mL.

[0054] The dose and dosing regimen of an anti-ILT7 antibody or antigen-binding fragment thereof disclosed herein may be such that any therapeutic effect achieved from administration of an anti-ILT7 antibody or antigen-binding fragment thereof to treat any myositis disease or disorder, may be considered to be “long-lasting.” A “long-lasting” effect of an anti-ILT7 antibody or antigen-binding fragment thereof in the treatment of a myositis disease or disorder is one in which the therapeutic effect achieved by an anti-ILT7 antibody or antigen-binding fragment thereof is maintained (although an anti-ILT7 antibody or antigen-binding fragment thereof is no longer administered) over at least 4 weeks, at least 6 weeks, at least 8 weeks, at least 10 weeks, at least 12 weeks, at least 16 weeks, at least 20 weeks, at least 24, at least 28 weeks, at least 32 weeks, at least 36 weeks, at least 40 weeks, at least 44 weeks, at least 48 weeks, at least 1 year, at least 2 years, or up to about at least 5 years following a prior administration of an anti-ILT7 antibody or antigen-binding fragment thereof.

[0055] In aspects, administration of an anti-ILT-7 antibody or antigen-binding fragment thereof is effective in eliminating disease in a subject in need thereof. In aspects, administration of an anti-ILT-7 antibody or antigen-binding fragment thereof is effective in reducing disease in a subject in need thereof. In some cases, administration of an anti-ILT7 antibody or antigen-binding fragment thereof is effective in eliminating or reducing disease in a subject in need thereof for at least about 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 1 year, 2 years, 3 years, 4 years, at least about 5 years, or for the lifetime of the subject. In aspects, administration of an anti-ILT7 antibody or antigen-binding fragment thereof is effective in eliminating disease in a subject in need thereof for at least about 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks,11 weeks, or at least about 12 weeks. In aspects, administration of an anti-ILT7 antibody or antigen-binding fragment thereof is effective in eliminating or reducing disease in a subject in need thereof for at least about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, or at least about 12 months. In aspects, administration of an anti-ILT7 antibody or antigen-binding fragment thereof is effective in eliminating or reducing disease in a subject in need thereof for at least about 1 year, 2 years, 3 years, 4 years, 5 years, 6 years, 7 years, 8 years, 9 years, or at least about 10 years. In aspects, administration of an anti-ILT7 antibody or antigen-binding fragment thereof is effective in eliminating or reducing disease for the lifetime of a subject in need thereof.

[0056] In aspects, a subject in need thereof has been administered one or more standard of care therapies for the treatment of a myositis disease or disorder prior to the administration of an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, a standard of care therapy comprises a corticosteroid, a disease-modifying anti-rheumatic drug (DMARD), and / or an immunomodulatory agent. In aspects, a subject continues on a standard of care therapy while being administered an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, a standard of care therapy is administered as a second therapy. In aspects, any of the referenced therapies may be combined in a therapeutic regimen for the treatment of a myositis disease or disorder. In aspects, a subject is treated with both an anti-ILT7 antibody or antigen-binding fragment thereof and a standard of care therapy.

[0057] In aspects, any of the standard of care therapies are combined as part of a treatment regimen or combination therapy. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered sequentially with any therapy disclosed herein. In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof may generally be administered concurrently with any second therapy disclosed herein. In aspects, a subject in need thereof has been administered any standard of care therapy for the treatment of a myositis disease or disorder prior to the administration of an anti-ILT7 antibody or antigen-binding fragment thereof.

[0058] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof is administered to a subject in need thereof. In aspects, a subject in need thereof has a myositis disease or disorder. In aspects, a subject has a myositis disease or disorder, and the disease is dermatomyositis (DM). In aspects, a subject has a myositis disease, and the disease is anti-synthetase inflammatory myositis (ASIM). In aspects, a subject in need thereof istreated with a method comprising concurrent administration of an immunomodulatory agent and an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, a subject in need thereof is treated with a method comprising concurrent administration of a DMARD and an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, a DMARD and an immunomodulatory agent are the same drug. In aspects, a subject in need thereof is treated with a method comprising concurrent administration of a corticosteroid and an anti-ILT7 antibody or antigen-binding fragment thereof.

[0059] Methods of the disclosure can comprise tapering of one or more standard of care therapeutics and / or an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, a method comprises tapering of a standard of care therapy. In aspects, a method comprises tapering of a corticosteroid. In aspects, a method comprises tapering of prednisone. The tapering can occur at any time. In aspects, tapering occurs before administration of an anti- ILT7 antibody or antigen-binding fragment thereof. In aspects, tapering occurs concurrent with administration of an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, tapering occurs after administration of an anti-ILT7 antibody or antigen-binding fragment thereof.

[0060] DMARD

[0061] In aspects, a subject is administered a DMARD. In aspects, a subject is administered a DMARD in combination with an anti-ILT7 antibody or antigen-binding fragment thereof as disclosed in any of the methods herein. In aspects, a DMARD is a conventional DMARD (cDMARD). In aspects, a DMARD is biologic DMARD (bDMARD). Exemplary DMARDS are selected from the group consisting of, but not limited to, methotrexate, sulfasalazine, leflunomide, hydroxychloroquine, Plaquenil, ciclosporin, etanercept, baricitinib, tofacitinib, upadacitinib, infliximab, adalimumab, certolizumab, and golimumab, and combinations thereof. In aspects, a DMARD is Plaquenil or ciclosporin.

[0062] Immunomodulatory Agent

[0063] In aspects, a subject is administered an immunomodulatory agent. In aspects, a subject is administered a immunomodulatory agent in combination with an anti-ILT7 antibody or antigen-binding fragment thereof as disclosed in any of the methods herein. In aspects, an immunomodulatory agent comprises a cell -modifying agent, an interleukin, or a pathway modifier. In aspects, an immunomodulatory agent is selected from the group consisting of, but not limited to, rituximab, ofatumumab, obinutuzumab, ibritumomab, azathioprine, abatacept, Belatacept, adalimumab, cyclophosphamide, mycophenolatemofetil, thymoglobulin, alemtuzumab, basiliximab, ciclosporin, sirolimus, tacrolimus, everolimus, and the like. In aspects, an immunomodulatory agent is azathioprine, ciclosporin, mycophenolate mofetil, or tacrolimus.

[0064] Corticosteroid

[0065] In aspects, a subject is administered a corticosteroid. In aspects, a subject is administered a corticosteroid in combination with an anti-ILT7 antibody or antigen-binding fragment thereof as disclosed in any of the methods herein. In aspects, a corticosteroid comprises a glucocorticoid. Glucocorticoids (GCs) are steroid hormones used for the treatment of inflammation, a myositis disease or disorder, and / or cancer. To exert their broad physiological and therapeutic effects, GCs bind to the GC receptor (GR) which belongs to the nuclear receptor superfamily of transcription factors. In aspects, one or more GCs are administered to a subject in need thereof. In aspects, one or more GCs is selected from the group consisting of, but not limited to, triamcinolone, methylprednisolone, budesonide, dexamethasone, triamcinolone, prednisone, hydrocortisone, dexamethasone, betamethasone, prednisolone, deflazacort, and combinations thereof. In aspects, a GC is prednisone. In aspects, a GC is methylprednisolone.

[0066] In aspects, treatment with a standard of care therapy in combination with an anti- ILT7 antibody or antigen-binding fragment thereof will be more effective in controlling disease activity than maintaining a standard of care therapy alone or replacing a partially effective standard of care therapy with an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, treatment with a standard of care therapy in combination with an anti- ILT7 antibody or antigen-binding fragment thereof is effective in reducing disease or a symptom in a subject in need thereof by at least about 1-fold, 10-fold, 50-fold, 100-fold, 200-fold, 500-fold, or up to about 1000-fold as compared to an otherwise comparable subject not administered an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, treatment with a standard of care therapy in combination with an anti-ILT7 antibody or antigen-binding fragment thereof is more effective in stabilizing a disease than maintaining a standard of care therapy alone or replacing a partially effective standard of care therapy with an anti-ILT7 antibody or antigen-binding fragment thereof.

[0067] In aspects, one or more standard of care therapies are administered for about 1, about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 11, about 12, about 13, about 14, about 15, about 20, about 25, about 30, about 35, about 40, about 52, about 52 weeks or more prior to the administration of an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, one or more standard of care therapies are administered for about 4 weeks prior to the administration of an anti-ILT7 antibody or antigen-binding fragment thereof.

[0068] A dose and dosing regimen of an anti-ILT7 antibody or antigen-binding fragment thereof as disclosed herein may be such that any therapeutic effect achieved from administration of an anti-ILT7 antibody or antigen-binding fragment thereof to treat any myositis disease or disorder, may be considered to be “long-lasting.” A “long-lasting” effect of an anti-ILT7 antibody or antigen-binding fragment thereof in a treatment of a myositis disease or disorder is one in which a therapeutic effect achieved by an anti-ILT7 antibody or antigen-binding fragment thereof is maintained (although the anti-ILT7 antibody or antigen-binding fragment thereof is no longer administered) over at least 4 weeks, at least 6 weeks, at least 8 weeks, at least 10 weeks, at least 12 weeks, at least 16 weeks, at least 20 weeks, least 24 weeks, at least 28 weeks, at least 32 weeks, at least 36 weeks, at least 40 weeks, at least 44 weeks, at least 48 weeks, or at least 52 weeks following administration of the last dose of a course of an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, less frequent dosing of any of the compositions provided herein may be advantageous. Exemplary advantages of less frequent dosing include but are not limited to reduced frequency of side effects associated with an administered composition, reduced treatment-associated toxicity, increased quality of life for treated subjects, and the like.Assessments

[0069] In aspects, a subject is assessed. In aspects, a subject is assessed as part of a treatment. In aspects, a subject having a confirmed or probable myositis disease or disorder is assessed as part of a treatment. An assessment can occur at any point before, during, or after administration with an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, an assessment is performed before an administration initiates. In aspects, an assessment is performed concurrent with an administration. In aspects, an assessment is performed after an administration finishes.

[0070] In aspects, a subject is assessed, and a baseline measurement of disease is determined. In aspects, a subject is assessed, and a baseline measurement of disease is determined at any point before, during, or after administration with an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, an assessment is performed, and a baseline measurement of disease is determined before an administration with an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, an assessment is performed, and a baselinemeasurement of disease is determined concurrent with an administration of an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, an assessment is performed, and a baseline measurement of disease is determined after an administration of an anti-ILT7 antibody or antigen-binding fragment thereof.

[0071] In aspects, a baseline measurement of disease increases or decreases in response to an administration of the disclosure or a lack thereof. In aspects, a baseline measurement of disease may increase and indicate effective treatment of a disease or disorder. In aspects, a baseline measurement of disease may decrease and indicate effective treatment of a disease or disorder. In aspects, a baseline measurement of disease increases or decreases after administration with an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, a baseline measurement of disease may increase after administration with an anti-ILT7 antibody or antigen-binding fragment and indicate effective treatment of a disease or disorder. In aspects, a baseline measurement of disease may decrease after administration with an anti-ILT7 antibody or antigen-binding fragment and indicate effective treatment of a disease or disorder.

[0072] In aspects, a baseline measurement of disease is compared to the measurement of disease of the subject after administration of the anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, a measurement of disease of a subject administered an anti- ILT7 antibody or antigen-binding fragment thereof increases as compared to a baseline measurement of disease measured prior to administration with an anti-ILT7 antibody or antigen-binding fragment. In aspects, a measurement of disease of a subject administered an anti-ILT7 antibody or antigen-binding fragment thereof decreases as compared to a baseline measurement of disease measured prior to administration with an anti-ILT7 antibody or antigen-binding fragment. In aspects, a measurement of disease of a subject administered an anti-ILT7 antibody or antigen-binding fragment thereof increases as compared to a baseline measurement of disease measured prior to administration with an anti-ILT7 antibody or antigen-binding fragment and indicates effective treatment. In aspects, a measurement of disease of a subject administered an anti-ILT7 antibody or antigen-binding fragment thereof decreases as compared to a baseline measurement of disease measured prior to administration with an anti-ILT7 antibody or antigen-binding fragment and indicates effective treatment.

[0073] In aspects an assessment comprises determining treatment efficacy. Efficacy can be determined by any of the assessments of the disclosure. In aspects, effectiveness atpreventing, reducing, or eliminating a myositis disease or disorder (e.g., DM or ASIM) is determined by detecting a change in baseline in a subject’s blood level of pDCs. In aspects, effectiveness at preventing, reducing, or eliminating a myositis disease or disorder is determined evaluating: pharmacokinetic parameters of an anti-ILT7 antibody or antigenbinding fragment thereof used to a treat a subject in need thereof, a change in baseline in a subject’s blood level of pDCs, a presence of anti-drug antibodies (ADA), and combinations thereof. In aspects, effectiveness at preventing, reducing, or eliminating a myositis disease or disorder is determined by determining pharmacokinetic parameters of an anti-ILT7 antibody or antigen-binding fragment thereof used to a treat a subject in need thereof. In aspects, effectiveness at preventing, reducing, or eliminating a myositis disease or disorder is determined by determining a change in baseline in a subject’s blood level of pDCs. In aspects, effectiveness at preventing, reducing, or eliminating a myositis disease or disorder is determined by determining a presence of ADA. In aspects, a myositis disease or disorder comprises DM or ASIM.

[0074] Any of the below-referenced assessments can occur at any time. In aspects, a subject is assessed by the minute, hourly, daily, weekly, monthly, quarterly, or yearly. In aspects, an assessment is completed twice daily, biweekly, bimonthly, or semiannually.

[0075] In aspects, an assessment is performed from day -28, -27, -26, -25, -24, -23, -22, - 21, -20, -19, -18, -17, -16, -15, -14, -13, -12, -11, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119,120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137,138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155,156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173,174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209,210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227,228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245,246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263,264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281,282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299,300, 301, 302, 303, 304, 305, 306, 307, 308 309, 310, 311, 312, 313, 314, 315, 316, 317,318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335,336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353,354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371,372, 373, 374, 375, 376, 377, 378, 379, 380, 381, 382, 383, 384, 385, 386, 387, 388, 389,390, 391, 392, 393, 394, 395, 396, 397, 398, or up to about day 399 post treatment. Timing of assessments are further described below.

[0076] Assessment of Inclusion

[0077] In aspects, a subject in need thereof is assessed prior to beginning treatment. An exemplary assessment or inclusion criterion comprises a subject having one or more chronic (i.e., stable) myositis diseases or disorders.

[0078] In aspects, a subject in need thereof may be either male or female. In aspects, a subject in need thereof is an adult subject. In aspects, a subject in need thereof may be aged between about 18 and 75 years of age.

[0079] In aspects, a subject in need thereof has a diagnosis of definite or probable myositis. In aspects, a subject in need thereof has a diagnosis of definite or probable myositis according to American College of Rheumatology (ACR) criteria. In aspects, a subject in need thereof has a diagnosis of definite or probable myositis according to European League Against Rheumatism (EULAR) criteria. In aspects, a subject in need thereof has a diagnosis of definite or probable myositis according to European League Against Rheumatism (EULAR) 2017 criteria. In aspects, a total aggregated score for ACR or EULAR 2017 is > 5.5 without a muscle biopsy. In aspects, a total aggregated score for ACR or EULAR 2017 is > 6.7 with muscle biopsy. In aspects, a subject in need thereof is not assessed by the ACR or EULAR 2017 criteria but does have a pathognomonic skin rash (e.g., heliotrope rash, Gottron’s papules and / or Gottron’s sign).

[0080] Idiopathic inflammatory myopathies (IIMs), such as myositis, can be classified into several subgroups: dermatomyositis (including amyopathic dermatomyositis), anti synthetase inflammatory myositis (ASIM), immune-mediated necrotizing myopathy, inclusion body myositis, polymyositis, and overlap myositis. In certain aspects, “polymyositis” includes ASIM and other forms of inflammatory myositis. In aspects, a subject in need thereof may have a probable or definite myositis diagnosis that comprises,but is not limited to: dermatomyositis (DM), anti-synthetase inflammatory myositis (ASIM), polymyositis, or both DM and ASIM, or DM and polymyositis.

[0081] In aspects, a subject in need thereof has a diagnosis of DM. In aspects, a subject in need thereof has a diagnosis of DM with a current DM rash prior to treatment initiation. In aspects, a subject in need thereof has a diagnosis of DM with a historical DM rash prior to treatment initiation. In aspects, a subject in need thereof has a diagnosis of ASIM. In aspects, a subject in need thereof has a diagnosis of ASIM and tests positive for anti-Jo-1 antibodies prior to treatment initiation. In aspects, a subject in need thereof has a diagnosis of ASIM and has historically tested positive for anti-PL-12, anti-PL-7, anti-KS, anti-EJ, anti-OJ, anti- ZO, or anti-YRS(HA) antibodies prior to treatment initiation. In aspects, a subject in need thereof has a manual muscle testing (MMT8) score <142, at least two abnormal core set measures (CSM), and a global muscle damage score < 5 on a 10 cm VAS on the myositis damage index (MDI) prior to treatment initiation. In aspects, two CSM are selected from the group consisting of: PtGDA > 2 cm in a 10 cm visual analog scale (VAS), Physician’s Global Disease Activity (PhGDA) > 2 cm in a 10 cm VAS, extramuscular activity > 2cm in a 10 cm VAS, at least one muscle enzyme 1.5 times upper limit of normal (ULN), and health assessment questionnaire-disability index (HAQ-DI) > 0.5.

[0082] In aspects, a subject in need thereof may have prior and / or concomitant therapy for treatment of a myositis disorder at the time of treatment initiation. In aspects, a subject in need thereof may have stable dosing of azathioprine, tacrolimus, ciclosporin, plaquenil, and / or mycophenolate mofetil for at least 4 weeks prior to treatment initiation. In aspects, a subject in need thereof may have stable dosing of methotrexate for at least 4 weeks prior to treatment initiation. In aspects, a subject in need thereof may have stable dosing of corticosteroids (e.g., prednisone or methylprednisolone) for at least 4 weeks prior to treatment initiation.

[0083] Immunogenicity

[0084] In aspects, an assessment comprises determining a level of immunogenicity, if any, of an anti-ILT7 antibody or antigen-binding fragment thereof of the disclosure. Immunogenicity comprises determining the presence of anti-drug antibodies (ADA) to an anti-ILT7 antibody or antigen-binding fragment thereof. The presence of ADA can be evaluated using a plasma sample from a subject administered an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, ADA are not detected post administration of an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, ADA levels arereduced as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof; for example, the reduction may be about: 10%, 15%, 20%, 25%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or up to 100% as compared to ADA levels in an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0085] In aspects, determining ADA levels to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, determining ADA levels to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 12 ± 3 days, Week 24 ± 3 days, Week 28 ± 3 days, Week 36 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation.

[0086] Skin Swabs

[0087] In aspects, an assessment can comprise assessing a skin microbiome. In aspects, a skin microbiome is sampled using a skin swab. In aspects, a profile of skin microbiome is collected and compared to a baseline level. In aspects, a skin microbiome profile changes by at least about 0.5 fold, 1 fold, 1.5 fold, 1-fold, 2-fold, 3-fold, 4-fold, 5-fold, 10-fold, 20- fold, 40-fold, 60-fold, 80-fold, 100-fold, 120-fold, 140-fold, 160-fold, 180-fold, 200-fold, 220-fold, 240-fold, 260-fold, 280-fold, or up to about 300-fold post administration as compared to baseline. Suitable methods to assess a skin microbiome may comprise qPCR, DNAseq, RNAseq, and exome sequencing, and combinations thereof.

[0088] In aspects, determining a change in a profile of a skin microbiome to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days,-26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, determining a change in a profile of a skin microbiome to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1 and Week 24 ± 3 days post treatment initiation.

[0089] Whole Blood Transcriptomics

[0090] In aspects, an assessment comprises quantifying expression levels of genes or gene pathways associated with disease activity by way of whole blood transcriptomics. In aspects, whole blood transcriptomics may be assessed via RNA isolation from whole blood. In aspects, RNA testing may be performed to assess changes over time in the expression of genes or gene pathways associated with myositis, mechanism of action of or in response to an anti-ILT7 antibody or antigen-binding fragment thereof administration, or the pathogenesis of myositis.

[0091] RNA may be isolated at baseline from whole blood to test for changes in expression levels of the genes or gene pathways associated with disease activity. In aspects, transcriptome profiling is assessed by methods including, but not limited to, qPCR, RNAseq, and exome sequencing.

[0092] In aspects, expression levels of genes associated with disease activity by way of RNA analysis may be reduced by at least about 1-fold, 2-fold, 3-fold, 4-fold, 5-fold, 10-fold, 20-fold, 40-fold, 60-fold, 80-fold, 100-fold, 120-fold, 140-fold, 160-fold, 180-fold, 200- fold, 220-fold, 240-fold, 260-fold, 280-fold, or up to about 300-fold post administration as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, expression levels of genes associated with disease activity by way of RNA analysis may be reduced by at least about 10%, 15%, 20%, 25%, 50%, 60%, 70%,80%, 90%, 95%, 96%, 97%, 98%, 99%, or up to 100% as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0093] In aspects, determining expression levels of genes associated with disease activity by way of RNA analysis to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks,22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, determining expression levels of genes associated with disease activity by way of RNA analysis to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 12 ± 3 days, Week 24 ± 3 days, Week 36 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation. In aspects, whole blood samples may be collected and may be assessed by way of RNA analysis. In aspects, whole blood samples may be collected and may be assessed by way of metabolomics. In aspects, whole blood samples may be collected and may be assessed by way of proteomics. In aspects, whole blood samples may be collected and assessed by way RNA analysis, metabolomics, and / or proteomics.

[0094] Genetics

[0095] In aspects, an assessment comprises determining the sequence of genes associated with disease activity by way of whole blood DNA analysis. In aspects, DNA testing may be performed to assess changes over time in the sequence of genes, including: single nucleotide polymorphisms (SNPs) associated with the development of myositis (e.g., DM or ASIM) or Fc gamma receptor in genes that may be related to the mechanism of action of an anti-ILT7 antibody or antigen-binding fragment thereof.

[0096] In aspects, whole blood can be collected and may be used to evaluate gene sequences before, during, and after treatment with any of the compositions provided herein. Gene sequences found to be modulated by treatment may be analyzed in whole blood using quantitative methods. Samples may be used to examine gene sequences and their changes over time as assessed by NGS, Sanger Sequencing, or PCR.

[0097] In aspects, determining changes in gene sequences associated with disease activity and / or treatment efficacy by way of DNA analysis to an anti-ILT7 antibody or antigenbinding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, - 24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days,I week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks,I I weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, determining changes in gene sequences associated with disease activity and / or treatment efficacy by way of DNA analysis to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1 post treatment initiation.

[0098] Pharmacokinetic Assessment

[0099] In aspects, a method provided herein can comprise determining a concentration of an anti-ILT7 antibody or antigen-binding fragment thereof in a subject in need thereof post administration. In aspects, a method comprises a pharmacokinetic assessment. In aspects, a sample is a blood sample or a plasma sample, or a combination of both. In aspects, a suitable assay to measure pharmacokinetics may comprise electrochemiluminescence (ECL) assay, a bead-based assay, a cell-based assay, and combinations thereof. In aspects, a sample may comprise plasma and the plasma is assessed for an anti-ILT7 antibody or antigen-binding fragment thereof concentration by measuring: maximum observed concentration (Cmax), area under the concentration-time curve (AUC), clearance (CL), and terminal elimination half-life (ti / 2).

[0100] In aspects, a pharmacokinetic assessment to an anti-ILT7 antibody or antigenbinding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, - 24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days,I week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks,I I weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a pharmacokinetic assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 24 ± 3 days, Week 36 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation.

[0101] Pharmacodynamic Assessment

[0102] In aspects, a method comprises a pharmacodynamic assessment. In aspects, an assessment can occur over a period of time. In aspects, a sample comprises a blood sample, serum sample, plasma sample, skin sample, or muscle sample. In aspects, a muscle biopsy location may be identified by MRI. In aspects, a muscle biopsy may be taken via non- invasive surgery (e.g., biopsy needle) or invasive surgery (i.e., open biopsy). In aspects, a skin biopsy may be taken by punch biopsy.

[0103] In aspects, a method provided herein can comprise determining an amount of reduction or elimination of biomarkers, including but not limited to, pDCs, IFN-a, myxovirus resistance protein A (MxA), IFN gene signatures, and peripheral blood mononuclear cells (PBMCs), by an anti-ILT7 antibody or antigen-binding fragment thereof in a subject in need thereof post administration. In aspects, a reduction of biomarkers may be detected as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, elimination of a biomarker may be detected as compared to an otherwise comparable method wherein the subject of the otherwise comparable method isnot administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to an otherwise comparable method lacking the administering of an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, reduction of a biomarker comprises at least about or at most about: 1-fold, 2-fold, 3-fold, 4-fold, 5-fold, 10-fold, 15-fold, 20-fold, 25- fold, 30-fold, 35-fold, 40-fold, 45-fold, 50-fold, 55-fold, 60-fold, 65-fold, 70-fold, 75-fold, 80-fold, 85-fold, 90-fold, 95-fold, 100-fold, 105-fold, 110-fold, 115-fold, 120-fold, 125- fold, 130-fold, 135-fold, 140-fold, 145-fold, 150-fold, 155-fold, 160-fold, 165-fold, 170- fold, 175-fold, 180-fold, 185-fold, 19-fold, 195-fold, 200-fold, 210-fol, 220-fold, 230-fold, 240-fold, 250-fold, 260-fold, 270-fold, 280-fold, 290-fold, or up to about 300-fold reduction as compared to an otherwise comparable method lacking the administering. In aspects, treatment efficacy of an anti-ILT7 antibody or antigen-binding fragment thereof on a biomarker can be assessed over time using a suitable immunoassay. In aspects, effects of an anti-ILT7 antibody or antigen-binding fragment thereof are assessed over time using a qualified immunoassay.

[0104] The disclosure provides for an anti-ILT7 antibody containing compositions that efficiently reduce or deplete pDCs in a subject. Because an anti-ILT7 antibody or antigenbinding fragment thereof binds to and depletes a biomarker, the reduction or elimination can be used as a measure of treatment efficacy. In aspects, total pDCs is a measure of target engagement. Suitable assays to assess pDCs levels may comprise flow cytometry, histology, immunohistochemistry, blood analysis, microscopy, PCR, ELISA, and combinations thereof.

[0105] The disclosure provides for an anti-ILT7 antibody or antigen-binding fragment thereof containing compositions that efficiently reduce or eliminate blood MxA levels, cytokines, chemokines, or other proteins (e.g., IFN-a, IL-17, and IFN-y), PBMCs, or IFN gene signature levels, or a combinations thereof, in a subject. In aspects, changes in blood MxA levels, cytokines, chemokines, or other proteins (e.g., IFN-a, IL-17, and IFN-y), PBMCs, or IFN gene signature levels, or a combination thereof, may be related to the pathogenesis of myositis, or the action of an anti-ILT7 antibody or antigen-binding fragment thereof. Suitable assays to assess blood MxA levels, cytokines, chemokines, or other proteins (e.g., IFN-a, IL-17, and IFN-y), PBMCs, or IFN gene signature levels, or a combination thereof, may comprise flow cytometry, histology, immunohistochemistry, blood analysis, microscopy, PCR, ELISA, and combinations thereof.

[0106] In aspects, an anti-ILT7 antibody or antigen-binding fragment thereof may achieve at least about 10%, 15%, 20%, 25%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or up to about 100% reduction in pDCs levels as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti- ILT7 antibody or antigen-binding fragment thereof. Reduction or elimination of pDCs, blood MxA levels, cytokines, chemokines, or other proteins (e.g., IFN-a, IL- 17, and IFN- y), PBMCs, or IFN gene signature levels, or a combination thereof, may persist for extended periods of time. In aspects, depletion of pDCs, blood MxA levels, cytokines, chemokines, or other proteins (e.g., IFN-a, IL-17, and IFN-y), PBMCs, or IFN gene signature levels, or a combination thereof, may persist for at least 1 day, at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least10 days, at least 15 days, at least 20 days, at least 25 days, or at least 30 days. In another embodiment, depletion of pDCs, blood MxA levels, cytokines, chemokines, or other proteins (e.g., IFN-a, IL-17, and IFN-y), PBMCs, or IFN gene signature levels, or a combination thereof, may persist for at least 1 week, at least 2 weeks, at least 3 weeks, at least 4 weeks, at least 5 weeks, at least 6 weeks, at least 7 weeks, at least 8 weeks, at least 9 weeks, or at least 10 weeks. In aspects, depletion of pDCs, blood MxA levels, cytokines, chemokines, or other proteins (e.g., IFN-a, IL- 17, and IFN-y), PBMCs, or IFN gene signature levels, or a combination thereof, may persist for at least 1 month, at least 2 months, at least 3 months, at least 4 months, at least 5 months, at least 6 months, at least 7 months, at least 8 months, at least 9 months, at least 10 months, at least 11 months, or at least 12 months.

[0107] In aspects, a pharmacodynamic assessment to an anti-ILT7 antibody or antigenbinding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, - 24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks,11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a pharmacodynamic assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day -28, Day -27, Day -26, Day -25, Day -24, Day -23, Day -22, Day -21, Day -20, Day -19, Day -18, Day -17, Day -16, Day -15, Day -14, Day - 13, Day -12, Day -11, Day -10, Day -9, Day -8, Day -7, Day -6, Day -5, Day -4, Day -3, Day -2, Day -1, Day 0, Day 1, Week 4 ± 3 days, Week 12 ± 3 days, Week 24 ± 3 days, Week36 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation.

[0108] Health Assessment Questionnaire-Disability Index (HAQ-DI)

[0109] In aspects, an assessment comprises HAQ-DI. HAQ-DI assesses physical function of a subject in need thereof (HAQ-DI Form 05a). In aspects, HAQ-DI may be scored from about 0, 1, 2, or up to about 3. In aspects, a HAQ-DI score is at least about 0, about 1, about 2, or about 3. In aspects, HAQ-DI may comprise 8 sections: dressing and grooming, arising, eating, walking, hygiene, reach, grip, and common daily activities. In aspects, each section is scored from 0 (without any difficulty) to 3 (unable to do). In aspects, a HAQ-DI assessment may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subj ect’ s HAQ-DI score is reduced as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0110] In aspects, a HAQ-DI assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks,37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a HAQ- DI assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day -28, Day -27, Day -26, Day -25, Day -24, Day -23, Day -22, Day -21, Day -20, Day -19, Day -18, Day -17, Day -16, Day -15, Day -14, Day -13, Day -12, Day -11, Day -10, Day -9, Day -8, Day -7, Day -6, Day -5, Day -4, Day -3, Day -2, Day -1, Day 0, Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 20 ± 3 days, Week 24 ± 3 days, Week 28 ± 3 days, Week 32 ± 3 days, Week 36 ± 3 days, Week 40 ± 3 days, Week 44 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation.

[0111] Manual Muscle Testing 8 (MMT8) Bilateral

[0112] In aspects, an assessment comprises MMT8 bilateral. In aspects, MMT8 bilateral is a set of 8 designated muscles tested bilaterally (MMT8, 2007). In aspects, axial (neck flexors) testing is included, so the potential MMT8 score is up to about at least 150. In aspects, MMT8 bilateral may be scored from about 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85,86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107,108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125,126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,144, 145, 146, 147, 148, 148, or about 150. In aspects, MMT8 bilateral is from about 0-10, about 10-30, about 20-40, about 30-50, about 40-60, about 50-70, about 60-80, about 70-90, about 80-100, about 90-110, about 100-120, about 110-130, about 120-140, or about 130- 150. In aspects, a MMT8 bilateral assessment may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s MMT8 bilateral score is increased as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0113] In aspects, a MMT8 bilateral assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, - 12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a MMT8 bilateral assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day -28, Day -27, Day -26, Day -25, Day -24, Day -23, Day -22, Day -21, Day -20, Day -19, Day -18, Day -17, Day -16, Day -15, Day -14, Day -13, Day -12, Day - 11, Day -10, Day -9, Day -8, Day -7, Day -6, Day -5, Day -4, Day -3, Day -2, Day -1, Day 0, Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 20 ± 3 days, Week 24 ± 3 days, Week 28 ± 3 days, Week 32 ± 3 days, Week 36 ± 3 days, Week 40 ± 3 days, Week 44 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation.

[0114] Global Myositis Disease Activity Assessment Tool (MDAAT) and Patient Global Disease Activity (PtGDA)

[0115] In aspects, an assessment comprises global MDAAT. Global MDAAT measures the degree of disease activity of extramuscular organ systems and muscles (MDAAT, 2005). In aspects, global MDAAT may include, but is not limited to, an assessment of physician global disease activity (PhGDA) and an extramuscular global assessment. PhGDA is a physician’s evaluation of overall disease activity (extramuscular organ systems plus muscle disease activity) based on clinical laboratory assessments. In aspects, global MDAAT may be scored from about 0, about 1, about 2, about 3, and up to about 4. In aspects, global MDAAT is scored from about 0-4 or about 1-4. In aspects, PhGDA may be scored using a 10 cm VAS that ranges from 0 (no evidence of disease activity) to 4 (extremely severe disease activity). In aspects, an extramuscular global assessment evaluates disease activity in all extramuscular systems (excluding muscle disease activity) using a 10 cm VAS that ranges from 0 (no evidence of disease activity) to 4 (extremely severe disease activity). In aspects, a global MDAAT assessment uses an activity index that range from 0 (“not present in the last 4 weeks”) to 4 (“new in the last four weeks”). In aspects, a global MDAAT assessment may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof may be considered to have complete response if, during the study, they have no evidence of disease activity (i.e., PhGDA VAS = 0).

[0116] In aspects, a subject’s global MDAAT score is reduced as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0117] In aspects, a MDAAT assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a MDAAT assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day -28, Day -27, Day -26, Day -25, Day -24, Day -23, Day -22, Day - 21, Day -20, Day -19, Day -18, Day -17, Day -16, Day -15, Day -14, Day -13, Day -12, Day -11, Day -10, Day -9, Day -8, Day -7, Day -6, Day -5, Day -4, Day -3, Day -2, Day -1, Day 0, Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 20 ± 3 days, Week 24 ± 3 days, Week 28 ± 3 days, Week 32 ± 3 days, Week 36 ± 3 days, Week 40 ± 3 days, Week 44 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation.

[0118] In aspects, an assessment comprises patient global disease activity (PtGDA). PtGDA measures the global evaluation by the patient of the patient’s overall disease activity at the time of assessment (PtGDA Form 03). In aspects, a PtGDA assessment is scored from about 1, 2, 3, 4, 5, 6, 7, 8, 9, up to about 10. In aspects, PtGDA assessment is scored from about 0-10, about 1-5, about 4-10, or about 1-10. In aspects, PtGDA may be measured using a 10 cm visual analog scale (VAS) that ranges from “no evidence of disease activity” to “extreme active or severe disease activity.” In aspects, a PtGDA assessment may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s PtGDA score is reduced as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0119] In aspects, a PtGDA assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days,-23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a PtGDA assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day -28, Day -27, Day -26, Day -25, Day -24, Day -23, Day -22, Day -21, Day -20, Day -19, Day -18, Day -17, Day -16, Day -15, Day -14, Day -13, Day -12, Day -11, Day - 10, Day -9, Day -8, Day -7, Day -6, Day -5, Day -4, Day -3, Day -2, Day -1, Day 0, Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 20 ± 3 days, Week 24 ± 3 days, Week 28 ± 3 days, Week 32 ± 3 days, Week 36 ± 3 days, Week 40 ± 3 days, Week 44 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation.

[0120] Muscle-Associated Enzymes

[0121] In aspects, an assessment comprises measuring a level of a muscle-associated enzyme. Muscle-associated enzymes assessed may include, but are not limited to, alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), and aldolase, and combinations thereof. In aspects, whole blood, plasma, serum, and urine are collected to assessed levels of muscle-associated enzymes. In aspects, assessing a level of a muscle-associated enzyme may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, administration of an anti-ILT7 antibody or antigen-binding fragment thereof of the disclosure is effective in reducing a level of a muscle-associated enzyme in a subject by at least about or at most about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or up to about 100% of the level prior the administration. In aspects, administration of an anti-ILT7 antibody or antigen-binding fragment thereof of the disclosure is effective in reducing a level of a muscle-associatedenzyme in a subject by at least about or at most about: 3%-5%, 5%-l 0%, 10%-20%, or 5%- 25% as compared to a baseline level prior to the administration.

[0122] In aspects, an assessment of a level of a muscle-associated enzyme to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, an assessment of a level of a muscle-associated enzyme to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day - 28, Day -27, Day -26, Day -25, Day -24, Day -23, Day -22, Day -21, Day -20, Day -19, Day -18, Day -17, Day -16, Day -15, Day -14, Day -13, Day -12, Day -11, Day -10, Day -9, Day -8, Day -7, Day -6, Day -5, Day -4, Day -3, Day -2, Day -1, Day 0, Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 20 ± 3 days, Week 24 ± 3 days, Week 28 ± 3 days, Week 32 ± 3 days, Week 36 ± 3 days, Week 40 ± 3 days, Week 44 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation.

[0123] Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI)

[0124] In aspects, an assessment comprises a CDASI measurement. A CDASI measurement may be used to assess the severity of cutaneous DM and detect improvement in disease activity. In aspects, CDASI may be scored from about 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36,37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84,85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, and up to about 100. In aspects, CDASI is scored from about 0-10, about 1-10, about 0-30, about 1-30, about 10-30, about 0-40, about 1-40, about 20-40, about 30-50, about 40-60, about 50-70, about 60-80, about 70-90, about 0-100, about 1-100, or about 80-100. A CDASI activity scale may range from0-100 and the damage scale may range from 0-32. In aspects, the CDASI scale may rate disease involvement in 15 different body areas using 3 activity (erythema, scale, and erosion / ulceration) and 2 damage (poikiloderma and calcinosis) measures. In aspects, a CDASI measurement may assess the presence and severity of Gottron’s papules on the hands, periungual changes, alopecia, or combinations thereof. In aspects, a CDASI assessment may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subj ect’ s CDASI score is reduced as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0125] In aspects, a CDASI measurement to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a CDASI measurement to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 24 ± 3 days, Week 36 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0126] Myositis Damage Index (MDI)

[0127] In aspects, an assessment comprises an MDI survey. An MDI survey may be used to assess the degree of disease damage of all organ systems (MDI Form 08, 2001). In aspects, an MDI survey may comprise a series of organ-specific questions relating to the presence or absence of a given sign or symptom or problem to measure the extent of damage. In aspects, an MDI survey is scored from about 0, 1, 2, 3, up to about 4. In aspects, an MDI survey is scored from about 0-4, or about 1-4. In aspects, an MDI survey is scored using a 10 cm VAS to measure the severity of damage from 0 (“no evidence of disease”) to 4(“extreme or maximum disease damage”). In aspects, an MDI survey may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s MDI score is reduced as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0128] In aspects, an MDI survey to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, an MDI survey to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day - 28, Day -27, Day -26, Day -25, Day -24, Day -23, Day -22, Day -21, Day -20, Day -19, Day -18, Day -17, Day -16, Day -15, Day -14, Day -13, Day -12, Day -11, Day -10, Day -9, Day -8, Day -7, Day -6, Day -5, Day -4, Day -3, Day -2, Day -1, Day 0, Day 1, Week 24 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0129] Myositis Functional Index 3 (FI3)

[0130] In aspects, an assessment comprises a myositis FI3 assessment. A myositis FI3 assessment may be used to assess the functional outcome of muscle endurance and function of frequently affected muscle groups (MFI3 2016). In aspects, a myositis FI3 assessment is scored from about 1, 2, 3, 4, 5, 6, 7, 8, 9, up to about 10. In aspects, myositis FI3 assessment is scored from about 0-10, about 1-5, about 4-10, or about 1-10. In aspects, a myositis FI3 score ranges from 0 (no exertion) to 10 (maximal exertion). In aspects, a myositis FI3 assessment is scored as the number of correctly performed repetitions with 60 or 120 maximal number of repetitions depending on the muscle group assessed. In aspects, a myositis FI3 assessment may comprise assessing a subject in need thereof administered ananti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s myositis FI3 score is reduced as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0131] In aspects, a myositis FI3 assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a myositis FI3 assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1, Week 12 ± 3 days, Week 24 ± 3 days, Week 36 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0132] Forced Vital Capacity (FVC)

[0133] In aspects, an assessment comprises a FVC measurement. A FVC measurement may be used to assess pulmonary function (e.g., lung compliance). In aspects, a FVC measurement measures the amount of air that can be forcibly exhaled from the lungs of a subject in need thereof. In aspects, an increase in a FVC measurement (e.g., lung compliance) comprises an increase in lung vascularity. In aspects, a FVC measurement may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigenbinding fragment thereof as compared to baseline. In aspects, a subject’s FVC measurement is increased as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0134] In aspects, a FVC measurement to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a FVC measurement to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day -28, Day -27, Day -26, Day -25, Day -24, Day -23, Day -22, Day -21, Day - 20, Day -19, Day -18, Day -17, Day -16, Day -15, Day -14, Day -13, Day -12, Day -11, Day -10, Day -9, Day -8, Day -7, Day -6, Day -5, Day -4, Day -3, Day -2, Day -1, Day 0, Day 1, Week 12 ± 3 days, Week 24 ± 3 days, Week 36 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0135] Skindexl6 Score

[0136] In aspects, an assessment comprises a Skindexl6 score. A Skindexl6 score may be used to rate skin conditions that have occurred within the previous week. In aspects, Skindexl6 may be scored from about 0, 1, 2, 3, 4, 5, and up to about 6. In aspects, a Skindexl6 score is a 16 item assessment that uses a scale from 0 (“never bothered”) to 6 (“always bothered”). In aspects, a Skindexl6 score is at least about 0, about 1, about 2, about 3, about 4, about 5, or about 6. In aspects, theses scores are categorized into 3 subscales: symptom, emotional, and functional. In aspects, a Skindexl6 score may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s Skindexl6 score is reduced as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof (Atherton et al., Expert. Opin. Drug Saf., 2009).

[0137] In aspects, a Skindexl6 score to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks,3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a Skindexl6 score to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 12 ± 3 days, Week 24 ± 3 days, Week 36 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0138] 36-Item Short Form (SF36) Survey

[0139] In aspects, an assessment comprises a SF36 survey. A SF36 survey may measure functional health and wellbeing from a subject with questions that span 8 health domains: physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health. In aspects, a SF36 survey may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s functional health and wellbeing is improved as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0140] In aspects, a SF36 survey assessment to an anti-ILT7 antibody or antigen -binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a SF36 survey assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can beassessed on about Day 1, Week 4 ± 3 days, Week 12 ± 3 days, Week 24 ± 3 days, Week 36 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0141] Patient-Reported Outcomes Measurement Information System (PROMIS) fatigue 8a

[0142] In aspects, an assessment comprises a PROMIS fatigue 8a survey. A PROMIS fatigue 8a survey may assess a range of self-reported symptoms, from mild subjective feelings of tiredness to an overwhelming, debilitating, and sustained sense of exhaustion. In aspects, fatigue is divided into the experience of fatigue (frequency, duration, and intensity) and the impact of fatigue on physical, mental, and social activities. In aspects, a PROMIS fatigue 8a survey assesses symptoms over the past week. In aspects, a PROMIS fatigue 8a survey may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s selfreported symptoms are improved as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0143] In aspects, a PROMIS fatigue 8a survey to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a PROMIS fatigue 8a survey to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 12 ± 3 days, Week 24 ± 3 days, Week 36 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0144] PROMIS Physical Function 8b

[0145] In aspects, an assessment comprises a PROMIS physical function 8b survey. APROMIS physical function 8b survey may assess a range of self-reported capability. APROMIS physical function 8b survey may include the functioning of a subject’s upper extremities (e.g., dexterity), lower extremities (e.g., walking or mobility), and central regions (e.g., neck and back), as well as daily activities (e.g., running errands). In aspects, a PROMIS physical function 8b survey may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s self-reported capability is improved as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0146] In aspects, a PROMIS physical function 8b survey to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, - 6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a PROMIS physical function 8b survey to an anti-ILT7 antibody or antigenbinding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 12 ± 3 days, Week 24 ± 3 days, Week 36 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0147] PROMIS Pain Interference 6a

[0148] In aspects, an assessment comprises a PROMIS pain interference 6a survey. A PROMIS pain interference 6a survey may assess the consequences of pain on a subject’s life. A PROMIS pain interference 6a survey may include the extent to which pain hinders engagement with social, cognitive, emotional, physical, and recreational activities. In aspects, a PROMIS pain interference 6a survey may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s pain hindrance is improved as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0149] In aspects, a PROMIS pain interference 6a survey to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, - 6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks,10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a PROMIS pain interference 6a survey to an anti-ILT7 antibody or antigenbinding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 12 ± 3 days, Week 24 ± 3 days, Week 36 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0150] PROMIS Dyspnea Severity Survey

[0151] In aspects, an assessment comprises a PROMIS dyspnea severity survey. A PROMIS dyspnea severity survey may assess the severity of breath of difficulty breathing in a subject experiencing a response to various activities (e.g., dressing oneself without help, preparing meals, walking up 20 stairs). In aspects, a PROMIS dyspnea severity survey may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s severity of breathing difficult is improved as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigenbinding fragment thereof.

[0152] In aspects, a PROMIS dyspnea severity survey to an anti-ILT7 antibody or antigenbinding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, - 24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks,11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks,28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a PROMIS dyspnea severity survey to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 12 ± 3 days, Week 24 ± 3 days, Week 36 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0153] Global Pain 24-hour Numeric Rating Scale (NRS) Survey

[0154] In aspects, an assessment comprises a global pain 24-hour NRS survey. A global pain 24-hour NRS survey may assess the intensity of pain a subject may have experienced in the past 24 hours. In aspects, global pain 24-hour NRS survey may be scored from about 1, 2, 3, 4, 5, 6, 7, 8, 9, and up to about 10. In aspects, a global pain 24-hour NRS survey is from about 0-5, about 0-10, or about 1-10. A global pain 24-hour NRS survey scale may range from 0 (no pain) to 10 (the most intense pain imaginable). In aspects, a global pain 24-hour NRS survey may comprise assessing a subject in need thereof administered an anti- ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s score is reduced as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0155] In aspects, a global pain 24-hour NRS survey to an anti-ILT7 antibody or antigenbinding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, - 24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days,I week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks,I I weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a global pain 24-hour NRS survey to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day -28, Day -27, Day -26, Day -25, Day -24, Day -23,Day -22, Day -21, Day -20, Day -19, Day -18, Day -17, Day -16, Day -15, Day -14, Day - 13, Day -12, Day -11, Day -10, Day -9, Day -8, Day -7, Day -6, Day -5, Day -4, Day -3, Day -2, Day -1, Day 0, Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 20 ± 3 days, Week 24 ± 3 days, Week 28 ± 3 days, Week 32 ± 3 days, Week 36 ± 3 days, Week 40 ± 3 days, Week 44 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation.

[0156] Patient’s Global Impression of Change (PGIC) Survey

[0157] In aspects, an assessment comprises a PGIC survey. A PGIC survey may use a categorical scale to ask a subject how much their myositis has changed. In aspects, a PGIC survey may be administered after a subject in need thereof has been administered an anti- ILT7 antibody or antigen-binding fragment thereof of the disclosure. In aspects, a PGIC survey score is at least about 1, about 2, about 3, about 4, or about 5. In aspects, a PGIC survey scale may range from 1 (much better) to 5 (much worse). In aspects, a level of a PGIC survey is reduced by at least about 1, about 2, about 3, or about 4 points post treatment with a composition provided herein. In aspects, a PGIC survey may comprise assessing a subject in need thereof administered an anti-ILT7 antibody or antigen-binding fragment thereof as compared to baseline. In aspects, a subject’s score is reduced as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0158] In aspects, a PGIC survey to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks,3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a PGIC survey to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Week4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 20 ± 3 days, Week24 ± 3 days, Week 28 ± 3 days, Week 32 ± 3 days, Week 36 ± 3 days, Week 40 ± 3 days, Week 44 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation.

[0159] Total Improvement Score (TIS) Based on the 6 Core Set Measures (CSM)

[0160] In aspects, an assessment comprises TIS. TIS is a composite score that includes an assessment of health assessment questionnaire-disability index (HAQ-DI), patient global disease activity (PtGDA), physician global disease activity (PhGDA), manual muscle testing 8 (MMT8) bilateral, laboratory muscle enzymes, and extramuscular global assessment (MRC 2016). In aspects, TIS may be scored from about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36,37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84,85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, and up to about 100. In aspects, TIS is from about 1-10, about 10-30, about 20-40, about 30-50, about 40-60, about 50-70, about 60-80, about 70-90, or about 80-100. The TIS may be > 20 or > 40. In aspects, the criteria may be used as a continuous outcome measure using the TIS. In aspects, the criteria may be used as a categorical outcome of improvement (minimal, moderate, or major improvement). In aspects, the criteria may be used as both a continuous outcome measure and a categorical outcome of improvement, and thus are a hybrid measure. In aspects, a change from baseline is determined. In aspects, a subject’s score is increased as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0161] In aspects, a TIS assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks,55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a TIS assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day -28, Day -27, Day -26, Day -25, Day -24, Day -23, Day -22, Day -21, Day -20, Day -19, Day -18, Day -17, Day -16, Day -15, Day -14, Day -13, Day -12, Day -11, Day -10, Day - 9, Day -8, Day -7, Day -6, Day -5, Day -4, Day -3, Day -2, Day -1, Day 0, Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 20 ± 3 days, Week 24 ± 3 days, Week 28 ± 3 days, Week 32 ± 3 days, Week 36 ± 3 days, Week 40 ± 3 days, Week 44 ± 3 days, Week 48 ± 3 days, and Week 56 ± 7 days post treatment initiation.

[0162] 28-Joint Count

[0163] In aspects, an assessment comprises 28-Joint Count. 28 specified joints are assessed for tenderness and swelling. In aspects, 28 specified joints comprise, but are not limited to, left and right shoulder, elbow, wrist, metacarpophalangeal (MCP)l, MCP2, MCP3, MCP4, MCP5, proximal interphalangeal (PIP)l, PIP2, PIP3, PIP4, and PIP5 joints of the upper extremities, and left and right knee of the lower extremities. In aspects, a change in 28-Joint count may be measured versus baseline. In aspects, a subject’s score is improved as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigen-binding fragment thereof.

[0164] In aspects, a 28-Joint Count assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a 28- Joint Count assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 20 ± 3 days, Week 24 ± 3 days, Week 28 ± 3 days, Week 32 ± 3 days, Week36 ± 3 days, Week 40 ± 3 days, Week 44 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0165] Actigraphy

[0166] In aspects, an assessment comprises actigraphy. Actigraphy is a measure of overall activity and sleep patterns, including duration and fragmentation of sleep. In aspects, an activity monitor device is an ActiGraph, a wearable watch device. In aspects, overall activity and changes in sleep patterns for a subject administered an anti-ILT7 antibody or antigenbinding fragment thereof are determined as compared to baseline. In aspects, a subject’s score is improved as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti-ILT7 antibody or antigenbinding fragment thereof.

[0167] In aspects, an actigraphy assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, -24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, an actigraphy assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 20 ± 3 days, Week 24 ± 3 days, Week 28 ± 3 days, Week 32 ± 3 days, Week 36 ± 3 days, Week 40 ± 3 days, Week 44 ± 3 days, and Week 48 ± 3 days post treatment initiation.

[0168] Handheld Dynamometry

[0169] In aspects, an assessment comprises handheld dynamometry. In aspects, handheld dynamometry may assess strong reliability, construct validity, and responsiveness in myositis patients (Saygin et al, 2021), especially to evaluate strength of single muscle groups(Baschung et al, 2018). Handheld dynamometry may be used to evaluate muscle strength. In aspects, a handheld dynamometry assessment may evaluate strength of a single muscle group at a time. In aspects, a handheld dynamometry assessment for a subject administered an anti-ILT7 antibody or antigen-binding fragment thereof is determined as compared to baseline. In aspects, a subject’s score is improved as compared to an otherwise comparable method wherein the subject of the otherwise comparable method is not administered an anti- ILT7 antibody or antigen-binding fragment thereof.

[0170] In aspects, a handheld dynamometry assessment to an anti-ILT7 antibody or antigenbinding fragment thereof can be assessed on about -28 days, -27 days, -26 days, -25 days, - 24 days, -23 days, -22 days, -21 days, -20 days, -19 days, -18 days, -17 days, -16 days, -15 days, -14 days, -13 days, -12 days, -11 days, -10 days, -9 days, -8 days, -7 days, -6 days, -5 days, -4 days, -3 days, -2 days, -1 day, 0 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days,I week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks,I I weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, 52 weeks, 53 weeks, 54 weeks, 55 weeks, or at least about 56 weeks post treatment initiation. In aspects, a handheld dynamometry assessment to an anti-ILT7 antibody or antigen-binding fragment thereof can be assessed on about Day 1, Week 4 ± 3 days, Week 8 ± 3 days, Week 12 ± 3 days, Week 16 ± 3 days, Week 20 ± 3 days, Week 24 ± 3 days, Week 28 ± 3 days, Week 32 ± 3 days, Week 36 ± 3 days, Week 40 ± 3 days, Week 44 ± 3 days, and Week 48 ± 3 days post treatment initiation.PHARMACEUTICAL COMPOSITIONS

[0171] In aspects, provided is a pharmaceutical composition. A pharmaceutical composition can comprise an anti-ILT7 antibody or antigen-binding fragment thereof. In aspects, a pharmaceutical composition is part of a therapeutic regimen that comprises an anti-ILT7 antibody or antigen-binding fragment thereof and one or more additional therapeutics provided herein. In aspects, the one or more additional therapeutics can comprise a corticosteroid, a DMARD, or an immunomodulatory agent, or a combination thereof.

[0172] Many drugs can be administered orally as liquids, capsules, tablets, or chewable tablets. Because the oral route is the most convenient and usually the safest and leastexpensive, it is the one most often used. However, it has limitations because of the way a drug typically moves through the digestive tract. For drugs administered orally, absorption may begin in the mouth and stomach. However, most drugs are usually absorbed from the small intestine. The drug passes through the intestinal wall and travels to the liver before being transported via the bloodstream to its target site. The intestinal wall and liver chemically alter (metabolize) many drugs, decreasing the amount of drug reaching the bloodstream. Consequently, these drugs are often given in smaller doses when injected intravenously to produce the same effect.

[0173] For a subcutaneous route, a needle is inserted into fatty tissue just beneath the skin. After a drug (e.g., an anti-ILT7 antibody or antigen-binding fragment thereof) is injected, it then moves into small blood vessels (capillaries) and is carried away by the bloodstream. Alternatively, a drug reaches the bloodstream through the lymphatic vessels. The intramuscular route is preferred to the subcutaneous route when larger volumes of a drug product are needed. Because the muscles lie below the skin and fatty tissues, a longer needle is used. Drugs are usually injected into the muscle of the abdomen (avoiding a 2-inch radius around the umbilicus), upper arm, thigh, or buttock. How quickly the drug is absorbed into the bloodstream depends, in part, on the blood supply to the muscle: the sparser the blood supply, the longer it takes for the drug to be absorbed. For the intravenous route, a needle is inserted directly into a vein. A solution containing the drug may be given in a single dose or by continuous infusion. For infusion, the solution is moved by gravity (from a collapsible plastic bag) or, more commonly, by an infusion pump through thin flexible tubing to a tube (catheter) inserted in a vein, usually in the forearm.

[0174] In aspects, a pharmaceutical composition provided herein is administered via infusion. An infusion can take place over a period of time. For example, an infusion can be an administration of a pharmaceutical over a period of about 5 minutes to about 10 hours. An infusion can take place over a period of about 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, or up to about 10 hours. In aspects, intravenous administration is used to deliver a precise dose quickly and in a well-controlled manner throughout the body. It is also used for irritating solutions, which would cause pain and damage tissues if given by subcutaneous or intramuscular injection. When given intravenously, a drug is delivered immediately to the bloodstream and tends to take effect more quickly than when given by any other route. Consequently, health care practitionersclosely monitor people who receive an intravenous injection for signs that the drug is working or is causing undesired side effects. Also, the effect of a drug given by this route tends to last for a shorter time. Therefore, some drugs must be given by continuous infusion to keep their effect constant. In aspects, infusion reactions can occur and include headache, nausea, somnolence, dyspnea, fever, myalgia, rash, or other symptoms. Potential risks associated with administration of an anti-ILT7 antibody or antigen-binding fragment thereof are infection, redness, swelling, pain, and induration at the administration site. Prior to each IV infusion subjects may receive prophylaxis with IV methylprednisolone, oral diphenhydramine, and oral acetaminophen, or equivalent(s) to reduce the risk or severity of potential reactions.

[0175] In aspects, a pharmaceutical is administered intrathecally. For the intrathecal route, a needle is inserted between two vertebrae in the lower spine and into the space around the spinal cord. The drug is then injected into the spinal canal. A small amount of local anesthetic is often used to numb the injection site. This route is used when a drug is needed to produce rapid or local effects on the brain, spinal cord, or the layers of tissue covering them (meninges) — for example, to treat infections of these structures.

[0176] Drugs administered by inhalation through the mouth can be atomized into smaller droplets than those administered by the nasal route, so that the drugs can pass through the windpipe (trachea) and into the lungs. How deeply into the lungs they go depends on the size of the droplets. Smaller droplets go deeper, which increases the amount of drug absorbed. Inside the lungs, they are absorbed into the bloodstream. Drugs applied to the skin are usually used for their local effects and thus are most commonly used to treat superficial skin disorders, such as psoriasis, eczema, skin infections (viral, bacterial, and fungal), itching, and dry skin. The drug is mixed with inactive substances. Depending on the consistency of the inactive substances, the formulation may be an ointment, cream, lotion, solution, powder, or gel.

[0177] In aspects, a treatment regime comprising a pharmaceutical composition may be dosed according to a body weight of a subject. In subjects who are determined obese (BMI > 35) a practical weight may need to be utilized. In aspects, body surface area may be utilized to calculate a dosage.

[0178] In aspects, a pharmaceutical composition can be administered either alone or together with a pharmaceutically acceptable carrier or excipient, by any routes, and such administration can be carried out in both single and multiple dosages. More particularly, apharmaceutical composition can be combined with various pharmaceutically acceptable inert carriers in the form of tablets, capsules, lozenges, troches, hand candies, powders, sprays, aqueous suspensions, injectable solutions, elixirs, syrups, and the like. Such carriers include solid diluents or fillers, sterile aqueous media and various non-toxic organic solvents, etc. Moreover, pharmaceutical formulations can be suitably sweetened and / or flavored by means of various agents of the type commonly employed for such purposes. Exemplary carriers and excipients can include dextrose, sodium chloride (NaCl), sucrose, lactose, cellulose, xylitol, sorbitol, maltitol, gelatin, PEG, PVP, D-histidine / D-histidine hydrochloride, L-histidine / L-histidine hydrochloride, trehalose dihydrate, polysorbate 80, and any combination thereof. In aspects, an excipient comprises: L-histidine / L-histidine hydrochloride, sucrose, and polysorbate 80.NUMBERED EMBODIMENTS

[0179] Notwithstanding the appended claims, the following numbered embodiments also form part of the instant disclosure.

[0180] 1. A method of treating dermatomyositis, the method comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigenbinding fragment thereof to a subject in need thereof, wherein the ILT7 antibody or antigenbinding fragment thereof comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg, and wherein the antibody is administered once every 4 weeks.

[0181] 2 The method of embodiment 1, wherein the dermatomyositis comprises definite myositis.

[0182] 3. The method of embodiment 1, wherein the dermatomyositis comprises probable myositis.

[0183] 4. A method of treating anti -synthetase inflammatory myositis (ASIM), the method comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigen-binding fragment thereof to a subject in need thereof, wherein the ILT7 antibody comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences ofSEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg, and wherein the antibody is administered once every 4 weeks.

[0184] 5. The method of embodiment 4, wherein the ASIM comprises definite myositis.

[0185] 6. The method of embodiment 4, wherein the ASIM comprises probable myositis.

[0186] 7 A method of treating a disease, the method comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigenbinding fragment thereof to a subject in need thereof, wherein the ILT7 antibody comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount comprises a dosage from about 300 mg, and wherein the administering is completed once every 4 weeks.

[0187] 8. A method of treating a disease, the method comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigenbinding fragment thereof to a subject in need thereof, wherein the ILT7 antibody comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, and wherein the administration is effective in reducing disease as compared to: (a) disease in an otherwise comparable subject lacking the administering; or (b) a baseline measurement of disease in the subject in need thereof.

[0188] 9. The method of any one of embodiments 1-8, wherein the administering is continued for at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or up to about 15 administrations.

[0189] 10. The method of any one of embodiments 8-9, wherein the administering is effective in reducing disease as compared to (b) the baseline measurement of disease in the subject in need thereof, and wherein the reduction is determined by detecting a reduced total improvement score in the subject.

[0190] 11. The method of any one of embodiments 8-9, wherein the administering is effective in reducing disease as compared to (b) the baseline measurement of disease in the subject in need thereof, and wherein the reduction is determined by detecting a reduced level of a symptom of the disease in the subject.

[0191] 12. The method of any one of embodiments 10-11, wherein the determination is completed after 6 and / or 12 administrations.

[0192] 13. The method of any one of embodiments 10-12, wherein the total improvement score is > 10, 20, 30, 40, or 50.

[0193] 14. The method of embodiment 13, wherein the total improvement score is > 20.

[0194] 15. The method of embodiment 13, wherein the total improvement score is > 40.

[0195] 16. The method of any one of embodiments 11-15, wherein the reduced level of the symptom comprises a reduction in a score of an assessment, as compared to baseline, selected from the group consisting of: Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI), Myositis Disease Activity Assessment Tool (MDAAT), myositis damage index (MDI), and combinations thereof.

[0196] 17. The method of any one of embodiments 11-15, wherein the reduced level of the symptom comprises an increase in lung compliance as determined by an increase in forced vital capacity (FVC) as compared to baseline.

[0197] 18. The method of any one of embodiments 8-9, wherein the administering is effective in reducing disease as compared to (b) the baseline measurement of disease in the subject in need thereof, and wherein the reduction is determined by a decrease in use of a corticosteroid, and wherein the determination is completed after 6 administrations.

[0198] 19. The method of embodiment 18, wherein the corticosteroid comprises prednisone.

[0199] 20. The method of any one of embodiments 18-19, wherein the decrease comprises a reduction in frequency of use at least about 10%, 15%, 20%, 25%, 30%, or 40%.

[0200] 21. The method of any one of embodiments 18-19, wherein the decrease is from about a > 10 mg / day dosage to a 7.5 mg / day dosage.

[0201] 22. The method of any one of embodiments 1-21, wherein the ILT7 antibody comprises a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH and the VL regions comprise an amino acid sequence at least 80% identical to SEQ ID NO: 2 and SEQ ID NO: 7, respectively.

[0202] 23. The method of any one of embodiments 1-22, wherein the ILT7 antibody comprises a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH and the VL regions comprise the amino acid sequence of SEQ ID NO: 2 and SEQ ID NO: 7, respectively.

[0203] 24. The method of any one of embodiments 1-23, wherein the ILT7 antibody is a monoclonal antibody.

[0204] 25. The method of any one of embodiments 1-24, wherein the ILT7 antibody is afucosylated.

[0205] 26. The method of any one of embodiments 4-25, wherein a sample of the subject in need is positive for one or more ASIM-associated antibodies.

[0206] 27. The method of embodiment 26, wherein the one or more ASIM-associated antibodies is selected from the group consisting of: anti-Jo-1, anti-PL-12, anti-PL-7, anti- KS, anti-EJ, anti-OJ, anti-ZO, and anti-YRS(HA).

[0207] 28. The method of any one of embodiments 1-27, wherein the subject in need thereof has a dermatomyositis-related rash.

[0208] 29. The method of any one of embodiments 1-28, wherein the disease is effectuated by plasmacytoid dendritic cells.

[0209] 30. The method of any one of embodiments 1-29, wherein the administration is effective in reducing a level of a type I interferon in the subject as compared to a baseline level of the subject.

[0210] 31. The method of embodiment 30, wherein the level is reduced by at least about 1- fold, 5-fold, 10-fold, 25-fold, 50-fold, 75-fold, 100-fold, 150-fold, or 250-fold.

[0211] 32. The method of any one of embodiments 7-31, wherein the administering is effective in eliminating the disease for at least about 3 months, 6 months, 1 year, or 2 years.

[0212] 33. The method of any one of embodiments 1-32, wherein the administering is subcutaneous.

[0213] 34. A method of treating dermatomyositis, the method comprising subcutaneously administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigen-binding fragment thereof to a subject in need thereof, wherein the ILT7 antibody or antigen-binding fragment thereof comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg.

[0214] 35. A method of treating anti -synthetase inflammatory myositis (ASIM), the method comprising subcutaneously administering an effective amount of an anti- Immunoglobulin-like transcript-7 (ILT7) antibody or antigen-binding fragment thereof to asubject in need thereof, wherein the ILT7 antibody comprises Complementarity- Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg.EXAMPLESExample 1 - A phase 2, randomized, double-blind, placebo-controlled, efficacy and safety study of Daxdilimab subcutaneous injection in adult participants with inadequately controlled dermatomyositis or anti-synthetase inflammatory myositis.

[0215] A Phase 2, randomized, double-blind, placebo-controlled, efficacy and safety study of Daxdilimab subcutaneous injection in adult participants with inadequately controlled dermatomyositis or anti-synthetase inflammatory myositis is disclosed herein.Objectives and endpoints

[0216] Study objectives and endpoints are presented in Table 2 and are the same for DM and ASIM, with an independent analysis of the two populations.Table 2. Exemplary objectives and endpoints.ADA = anti drug antibodies; CDASI = cutaneous dermatomyositis disease area and severity index; CSM = core set measures; CTCAE = common terminology criteria for adverse events; FI3 = functional index 3; FVC = forced vital capacity; HAQ-DI = health assessment questionnaire-disability index; IFN = interferon; MDAAT = myositis disease activity assessment tool; MDI = myositis damage index; MMT8 = manual muscle testing; MRI = magnetic resonance imaging; MxA = myxovirus resistance protein A; NRS = numeric rating scale; OCS = oral corticosteroid; PD = pharmacodynamics; pDCs = plasmacytoid dendritic cells; PhGDA = physician global disease activity; PtGDA = patient global disease activity; PGIC = patient global impression of change; PK = pharmacokinetics; PROMIS = patient-reported outcomes measurement information system; SF36 = 36- item short form survey; TIS = total improvement score.Study design

[0217] This study is a Phase 2, randomized, double-blind, placebo-controlled, proof of concept study to assess the efficacy and safety of Daxdilimab in participants aged >18 to <75 years with dermatomyositis (DM) or anti -synthetase inflammatory myositis (ASIM).

[0218] The study will enroll 2 idiopathic inflammatory myositis participant populations(FIG. 1)• Population 1 or DM: participants with DM with definite or probable myositis according to the American College of Rheumatology / European League Against Rheumatism 2017 (ACR / EULAR 2017) (Lundberg et al, 2019) criteria and a DM rash.• Population 2 or ASIM: participants with ASIM with definite or probable myositis according to ACR / EULAR 2017 criteria and a positive ASIM associated antibody.

[0219] Up to 96 participants will be randomized by population in a 1 : 1 ratio (24 participants per group) to receive the investigational product (IP; Daxdilimab 300 mg or placebo) by subcutaneous (SC) injection clinic once every 4 weeks (Q4W):• Group 1 : DM placebo• Group 2: DM Daxdilimab 300 mg• Group 3: ASIM placebo• Group 4: ASIM Daxdilimab 300 mg

[0220] Randomization may take place up to 28 days after successful screening, and it will be stratified by Manual Muscle Testing 8 (MMT8) score (< 120 vs >120) at Baseline (Day 1).The estimated total study duration, from screening to the end of the safety follow-up (SFU) period, will be up to 60 weeks with visits to the clinic Q4W (Table 3):32. Screening period of approximately 4 weeks (Days -28 to -1)33. Treatment period from Day 1 through Week 48- Randomization (double-blinded) on Day 1- Administration of IP from Day 1 through Week 44- Efficacy and safety assessments Q4W through Week 48- Consisting of a randomized control period (RCP) and an open-label extension (OLE) period: a. Randomized control period (double-blinded) from Day 1 through Week 24• Primary assessment of the efficacy endpoints will be done at Week 24, after which, participants in the placebo treatment groups (Groups 1 and 3) will be switched to receive 300 mg SC Q4W of Daxdilimab for an additional 24 weeks, and participants initially randomized to the Daxdilimab 300 mg treatment groups (Groups 2 and 4) will continue to receive 300 mg SC Q4W of Daxdilimab. b. Open-label extension from Week 24 through Week 48• Although all participants will receive active treatment from Week 24, the blind for previous treatment (prior to Week 24) will remain.

[0221] All administrations of IP will be administered by an unblinded pharmacist or nurse at the clinic and the participant may be observed for at least 60 minutes after the first and second doses and for 20 minutes for all subsequent doses. To maintain the blind for previous treatment, all participants may be observed for at least 60 minutes after the administration of IP at Weeks 24 and 28.

[0222] Efficacy assessments may include a series of scores, scales, and other measurements to assess disease activity, damage, and improvement.

[0223] Patient-reported outcomes may be used to record the wellbeing and quality of life of the participants during the study.

[0224] To characterize the pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of Daxdilimab, blood samples from all participants, and optional muscle and / or skin biopsies from those who agree, may be collected.

[0225] The study assessments scheduled on Day 1 may be performed before the administration of IP; patient-reported outcomes may be performed first, followed by the physician assessments, measurement of vital signs, and laboratory assessments.

[0226] In the event of a significant study-continuity issue (e.g., caused by a pandemic), alternate strategies for participant visits, assessments, medication distribution and monitoring may be implemented. The study may be conducted on an outpatient basis globally.End-of-Study Definition

[0227] The end of study is defined as the date of the last visit of the last participant in the study or last scheduled procedure (Week 56) shown in the Schedule of Assessments (SoA; Table 3) for the last participant in the study globally.

[0228] A participant is considered to have completed the study if the participant has completed all periods of the study including the last visit or the last scheduled procedure (Week 56) shown in the Table 3.Table 3. Exemplary schedule of assessments.ADA = antidrug antibody; AESI = AE of special interest; ALT = alanine transaminase; AST = aspartate transaminase; phCG = P-human chorionic gonadotropin; CBC = complete blood count; CDASI = cutaneous dermatomyositis disease area and severity index; CK = creatine kinase; DC = dendritic cells; ECG = electrocardiogram; FI = functional index; FSH = follicle-stimulating hormone; HAQ-DI = health assessment questionnaire -disability index; IFN = interferon; IP = investigational product; LDH = lactate dehydrogenase; MDAAT = myositis disease activity assessment tool; MDI = myositis damage index; MMT = manual muscle testing; MRI = magnetic resonance imaging; MSA = myositis-specific antibodies; MxA = myxovirus resistance protein A; NRS = numeric rating scale; PBMC = peripheral blood mononuclear cells; PGIC = patient global impression of change; PhGDA = physician global disease activity; PK = pharmacokinetics; PROMIS = patient-reported outcomes measurement information system; PtGDA = patient global disease activity; SF = short form; SFU = safety follow-up; SNP = single nucleotide polymorphism; TB = tuberculosis; Wk = week; X = to be performed. a Screening may be extended for 2 weeks. b Week 48 may correspond to the End of Investigational Product Visit if the participant discontinues IP prior to Week 44. Participants who complete the Week 48 visit will be offered to participate in a long-term extension study for safety and efficacy. Participants who enter this study directly after completion of the Week 48 visit may not complete the visits of the SFU period. c Week 52 visit may be performed as a phone call to the participant. d Week 56 or earlier may correspond to the End of Study / Early Termination Visit if the participant withdraws consent to participate in the study. e Participant eligibility may be checked on Day 1 prior to Randomization. f Questionnaires may be completed before any other procedures are performed. g For participants with interstitial lung disease, testing may be done more frequently if Investigator considers it clinically indicated. h Participants may be asked to wear it for 1 week after each visit, but they will be allowed to wear it longer if they wish to. i A complete physical examination at Screening and a focused physical examination at Weeks 24 and 48 including assessment of head, ears, eyes, nose, throat, lungs, heart, abdomen, skin, and extremities.j Vital signs include systolic and diastolic blood pressure may be obtained after at least 5 minutes at rest in a seated position, heart rate, respiratory rate (breaths / min), and body temperature. k May be performed after 10 minutes rest in supine position and after vital signs are collected.1 Skin biopsy may by performed by punch biopsy. m Participants undergoing muscle biopsy may first undergo an MRI scan either on their first or second visit, followed by the muscle biopsy on the same or the following day. These procedures may be performed before dosing. Day 1 visit procedures for these participants may take up to 3 days to be completed. These participants will be dosed one day after biopsy, once recovered. Day 1 may be counted from their first dosing day. n The results of an IFNy release assay (i.e., QuantiFERON-TB Gold Plus or T-SPOT) performed within 12 weeks of the Screening visit (if available) are acceptable, provided there is no reason to suspect any re-exposure. o Serum virology does not have to be repeated if performed within 12 weeks prior to Screening (e.g., Rescreening). Table 11 shows a complete list of serology assessments. p To confirm postmenopausal status, as appropriate. Estradiol and FSH tests do not have to be repeated if performed within 12 weeks prior to Screening (e.g., Rescreening). q In women of childbearing potential or women who are postmenopausal for less than 2 years prior to Screening, have nontherapy-induced amenorrhea for less than 12 months prior to Screening, or are not surgically sterile (absence of fallopian tubes, ovaries and / or uterus). r Go to Table 11 for a complete list of routine laboratory assessments. s Urine collection can be postponed for up to 14 days in women with menstrual bleeding or a urinary tract infection at the scheduled visit. Go to Table 11 for a complete list of routine urinalysis assessments. t Serum Daxdilimab PK may be obtained at Day 1 at approximately 2 hours or longer postdose, predose on Day 1 and Weeks 4, 8, 12, 16, 24, and 36; and any time on Weeks 48 and 56. u Collection of serum ADA samples may be performed prior to the administration of IP at all applicable visits. v Collection at Day 1 and at-home collection (fingerstick) at 1 week. w The time window for the administration of IPs is -13 days +14 days. All procedures and blood sampling may be collected before the administration.Study Population

[0229] Participants eligible for this study may have DM or ASIM.Inclusion Criteria

[0230] Participants are eligible to be included in the study the following criteria are met:

[0231] Age and Sex1. Adult men or women between 18 and 75 years of age at the time of signing the InformedConsent Form (ICF).

[0232] Type of Participant and Disease Characteristics2. A diagnosis of definite or probable myositis according to ACR / EULAR 2017 criteria:• Total aggregated score > 5.5 without a muscle biopsy• Total aggregated score > 6.7 with muscle biopsy• Pathognomonic skin rash (heliotrope rash, Gottron’s papules and / or Gottron’s sign) is required if no muscle biopsy is availableNote: the local muscle biopsy report will be used in the ACR / EURLAR 2017 criteria to determine participant eligibility. Submission of the historical biopsy sample (archived tissue block, physical slides, and / or digital pathology slides) for review of randomized participants is required.a. Population 1 : DM• Diagnosis of DM with DM rash current or historical, or b. Population 2: ASIM• Anti- Jo- 1 antibodies must be positive during Screening by central laboratory testing, or• One of following antibodies must be positive by historical testing: anti- PL-12, anti PL-7, anti-KS, anti-EJ, anti-OJ, anti-ZO, anti-YRS(HA).Note: participants with a DM rash and positive for anti-Jo-1 antibodies during Screening will be considered part of Population 2. Participants with historical anti Jo-1 who are negative by central laboratory anti- Jo- 1 testing during Screening will not be eligible.3. Currently active myositis with all the following (a, b, and c) during Screening: a. MMT8 score < 142 b. At least 2 other abnormal core set measures (CSM) from the following list:• PtGDA > 2cm in a 10 cm visual analog scale (VAS)• Physician’s Global Disease Activity (PhGDA) > 2 cm in a 10 cm VAS• Extramuscular activity > 2cm in a 10 cm VAS• At least one muscle enzyme 1.5 times upper limit of normal (ULN)• HAQ-DI > 0.5 c. Global muscle damage score < 5 on a 10 cm VAS on the myositis damage index (MDI)4. Participants should be on stable standard of care therapy if tolerated (a); if they are not able to tolerate it or have failed standard of care, medications should have washed out (b): a. Participants on corticosteroid treatment (up to 20 mg prednisone or equivalent per day) and / or up to 2, non-excluded, immunosuppressants on stable therapy (Table 6) for at least 4 weeks prior to Randomization or b. Participants with previous failure of response or previous intolerance to corticosteroid and at least 1 additional immunosuppressant drug, and with steroid / immunosuppressants washed out (Table 6).5. Participants should be willing to taper corticosteroid dose per protocol when stable or improving.

[0233] Sex and Contraceptive / Barrier Requirements6. A female participant is eligible to participate if she is not pregnant or breastfeeding, and one of the following conditions applies: a. Is a woman of nonchildbearing potential (WONCBP), or b. Is a women of childbearing potential (WOCBP), and: i. Has a negative serum pregnancy test at Screening and a negative urine pregnancy test at Day 1. ii. Agrees to use contraceptive methods that are highly effective from at least 4 weeks prior to Day 1 until at least 3 months after the last administration of IP or the end of the study, whichever is longer. iii. The Investigator is responsible for review of medical history, menstrual history, and recent sexual activity to decrease the risk for inclusion of a woman with an early undetected pregnancy.7. Male participants are eligible to participate if they agree to the following during the study and for at least 3 months after the last dose of IP:a. Refrain from donating sperm from Day 1 until at least 3 months after the last administration of IP.Plus, either: b. Be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long-term and persistent basis) and agree to remain abstinent, or c. Agree to use a male condom and an additional highly effective contraceptive method from Day 1 until at least 3 months after the last administration of IP when having sexual intercourse with a woman of childbearing potential who is not currently pregnant. If the female partner of a male participant uses a hormonal contraceptive method, it should be used by the female partner from at least 4 weeks before Day 1 until at least 3 months after the last administration of IP or the end of the study, whichever is longer.Exclusion Criteria

[0234] Participants are excluded from the study if any of the following criteria apply:

[0235] General Exclusion Criteria1. Participation in another clinical study with an investigational drug within 4 weeks prior to Randomization or within 5 published half-lives, whichever is longer.

[0236] Medical Conditions2. Any condition that, in the opinion of the Investigator or Sponsor, would interfere with the evaluation of IP or interpretation of participant safety or study results.3. Weight > 160 kg (352 pounds) at Screening.4. History of allergy, hypersensitivity reaction, or anaphylaxis to any component of the IP or to a previous mAb or human Ig therapy.5. Breastfeeding or pregnant women or women who intend to become pregnant anytime from signing the ICF through 6 months after receiving the last dose of IP.6. History of drug or alcohol abuse that, in the opinion of the Investigator, might affect participant safety or compliance with visits, or interfere with other study assessments.7. Major surgery within 8 weeks prior to Screening or elective surgery planned from Screening through Week 48.8. Spontaneous or induced abortion, still or live birth, or pregnancy < 4 weeks prior to Screening through Randomization.9. History of clinically meaningful cardiac disease including unstable angina, myocardial infarction, congestive heart failure within 6 months prior to Randomization; arrhythmia requiring active therapy, except for clinically insignificant extra systoles, or minor conduction abnormalities; or presence of clinically meaningful abnormality on ECG if, in the opinion of the Investigator, it would increase the risk of study participation.10. History of cancer within the past 5 years, except as follows:• In situ carcinoma of the cervix treated with apparent success with curative therapy > 12 months prior to Screening, or• Cutaneous basal cell or squamous cell carcinoma treated with curative therapy.11. Any underlying condition that in the opinion of the Investigator significantly predisposes the participant to infection.12. Participant who has given > 50 mL of blood or plasma within 30 days of Screening or > 499 mL of blood or plasma within 56 days of Screening (during a clinical study or ata blood bank donation) or plans to give blood or plasma during their participation in the study or up to 6 months after the last administration of IP, whichever is longer.13. Transfusion with blood, packed red blood cells, platelets or treatment with plasmapheresis, or plasma exchange within 8 weeks prior to Randomization and for the total duration of the study participation.

[0237] Laboratory Criteria14. Known history of a primary immunodeficiency or an underlying condition, such as known human immunodeficiency virus (HIV) infection, or a positive result for HIV infection per central laboratory.15. At Screening, any of the following per central laboratory tests (may be repeated once within the same screening period to confirm results prior to randomization):• Total bilirubin > 1.5 * ULN (unless due to Gilbert’s syndrome)• Neutrophil count < 1500 / pL (or < 1.5>< 109 / L)• Platelet count < 135,000 / pL (or < 135>< 109 / L)• Hemoglobin < 10 g / dL (or < 100 g / L)• Total lymphocyte count < 800 / pL (or < 0.8x 109 / L)

[0238] Infections Criteria16. Confirmed positive test for hepatitis B virus serology defined as:• Hepatitis B surface antigen, or• Hepatitis B core antibody17. Active tuberculosis (TB), or a positive IFN-y release assay (IGRA) test at Screening, unless documented history of appropriate treatment for active or latent TB according to local guidelines. Participants with an indeterminate IGRA test result can repeat the test, but if the repeat test is also indeterminate, they will be excluded.18. Any severe herpes virus family infection (including Epstein-Barr virus, cytomegalovirus [CMV]) at any time prior to Randomization, including, but not limited to, disseminated herpes, herpes encephalitis, recent recurrent herpes zoster (defined as 2 episodes within the last 2 years), or ophthalmic herpes.19. Any herpes zoster, CMV, or Epstein-Barr virus infection that was not completely resolved 12 weeks prior to Randomization.20. Any of the following within 30 days prior to signing the ICF and through Randomization:• Clinically meaningful active infection in the opinion of the Investigator, including ongoing, and chronic infection requiring antibiotics or antiviral medication (chronic nail infections are allowed).• Any infection requiring hospitalization or treatment with intravenous anti- infectives.• A participant with a documented positive SARS-CoV-2 test may be rescreened at least 2 weeks after a positive test if the participant is asymptomatic and at least 3 weeks after symptomatic COVID-19 illness.21. Opportunistic infection requiring hospitalization or parenteral antimicrobial treatment within 2 years prior to Randomization.22. Any acute illness or evidence of clinically meaningful active infection on Day 1.23. Participants who have COVID-19 or other significant infection, or in the judgment of the Investigator, may be at a high risk of COVID-19 or its complications should not be randomized.

[0239] Disease-Related Criteria24. Significant organ system involvement or myositis damage (global muscle damage score > 5 on a 10 cm VAS scale on the MDI) that poses risks in the study or impedes assessments.25. Diagnosis of immune-mediated necrotizing myopathy (IMNM) (positive anti-HMGR, anti-SRP, or antibody negative), inclusion body myositis (IBM) (including positive anti-cNIA), or drug-induced myositis.26. Current musculoskeletal, joint, or inflammatory disease, including significant joint contractures or calcinosis that in the opinion of the Investigator, could interfere with the muscle strength assessments and confound the disease activity assessments.27. Wheelchair bound participants28. Current inflammatory skin disease other than DM or ASIM that, in the opinion of the Investigator, could interfere with the inflammatory skin assessments or confound the disease activity assessments.29. Severe interstitial lung disease where respiratory symptoms limit participant function or progressive pulmonary fibrosis.30. Myositis in overlap with another connective tissue disease that precludes the accurate assessment of a treatment response (for example, difficulty in assessing muscle strength in a scleroderma patient with associated myositis).

[0240] Prior / Concomitant Therapy31. Use of Janus kinase inhibitors within 4 weeks prior to Randomization.32. Use of cyclophosphamide within 3 months prior to Randomization.33. Use of IVIG within 4 weeks prior to Randomization.34. Previous treatment with any biologic B-cell-depleting therapy (e.g., rituximab, ocrelizumab, or ofatumumab) or other B-cell targeting therapy (e.g., belimumab) within 3 months prior Randomization. B-cells should be detectable after therapy with these treatments prior to Randomization.35. Previous treatment with anti-BDCA2 [BIIB059] within 6 months prior to Randomization.36. Participants who have received previous treatment with Daxdilimab37. Any biologic or antiproliferative agents if last dose was taken:• Within 4 weeks prior to Randomization, or• Within drug-specific 5 half-lives elimination period (if longer than 4 weeks) prior to Randomization.38. Exposure to an experimental drug either 30 days, 5 half-lives of the agent, or twice the duration of the biological effect of the agent, whichever is longer, prior to Randomization and through the final study visit.39. Receipt of a live-attenuated vaccine within 4 weeks prior to Randomization.Lifestyle Considerations

[0241] In this study, there will be no food, caffeine, alcohol, and tobacco restrictions.Participants will only be asked to abstain from strenuous exercise for 24 to 48 hours beforeeach blood collection for clinical laboratory tests. Participants may participate in light recreational activities during study visits (e.g., watching television, reading).Investigational Products and Concomitant Therapy

[0242] Investigational Products are all prespecified medicinal products intended to be administered to the study participants during the study conduct (i.e., Daxdilimab and placebo).IPs administered

[0243] The IP Daxdilimab may be supplied as a 2R vial with nominal 1 mL of 100 mg / mL Daxdilimab containing 20 mM L histidine / L-histidine HC1, 240 mM sucrose, 0.02% (w / v) polysorbate 80, pH 6.0.

[0244] The placebo is supplied as a 2R vial with nominal 1 mL of 20 mM L histidine / L- histidine HC1, 240 mM sucrose, 0.02% (w / v) polysorbate 80, pH 6.0.

[0245] Both IPs may be administered by SC injection Q4W from Day 1 to Week 24. After Week 24 through Week 44, only Daxdilimab may be administered to all participants. To maintain the same number and volume of injections across all groups, the required dose may be administered as 2 injections of 1.5 mL.

[0246] Further details regarding the IPs can be found in Table 4.Table 4. Examples of investigational products (IPs) administered.2R = 2 mL injection vial; HC1 = hydrochloric acid; IMP = investigational medicinal product; IP = investigational product; NIMP / AxMP = not an IMP; Q4W = once every 4 weeks; SC = subcutaneousTable 5. Exemplary study groups.ASIM = anti-synthetase inflammatory myositis; DM = dermatomyositis; IP = investigational product;Q4W = once every 4 weeks; SC = subcutaneousBlinding• Participants will be randomly assigned in a 1 : 1 ratio to receive Daxdilimab 300 mg or placebo at Day 1 (see Table 5 for study groups).• Up to Week 24, the study may be double-blinded, which means that participants, Investigators, and site personnel will be unaware of the IP given to the participant.• At Week 24, the OLE period of the study will begin. Participants in the placebo groups (Groups 1 and 3) will be moved to a dose of 300 mg of Daxdilimab. Participants initially randomized to the Daxdilimab 300 mg groups (Groups 2 and 4) will remain on the same dose for the rest of the study.- Although all participants will receive active treatment from Week 24, the blind for previous treatment (prior to Week 24) will remain.Permitted Therapy

[0247] Participants are allowed to be on permitted standard of care medication (Table 6) if stable prior to Screening:• Azathioprine, tacrolimus, ciclosporin, plaquenil, and mycophenolate mofetil must be at a stable dosage for at least 4 weeks prior to Screening and through study.• Methotrexate (oral or SC) at stable dosage and route of administration for at least 4 weeks prior to Screening and through study.• Corticosteroids at stable dose up to 20 mg / day prednisone equivalent for at least 4 weeks prior to Screening. Investigators will taper prednisone (Table 9) from Weeks 4 to 20 and during OLE if participants are stable or improving.

[0248] If participants fail to respond to the medication, do not tolerate it, and / or decide to stop taking it, they may discontinue it according to the washout period prior to the first administration of IP at Day 1 visit (Table 6) and through the last study visit.Table 6. Exemplary permitted standard of care medicine.Prohibited Therapy

[0249] Participants who, during the study, start prohibited medications or new therapies that have been demonstrated to be effective for treatment of DM or ASIM (except those allowed as concomitant medication) may be withdrawn from IP.

[0250] Participants who start prohibited medications or therapies for other reasons during the study may be withdrawn from study treatment if an impact on efficacy assessment or safety of the participants is expected.

[0251] Table 7 lists prohibited medications that may not to be used from the defined washout periods before the first administration of IP at the Day 1 visit through the last study visit.Table 7. Exemplary prohibited therapies.BDCA2 = blood dendritic cell antigen 2; JAK, Janus kinase; IA = intra-articular; IG = immunoglobulin; IM = intramuscular; IV =intravenous; IVIG = intravenous immunoglobulin. a Prohibited during the first 24 weeks, after which it should be discussed with the medical monitor, b The use of other therapeutic IGs should be discussed with the medical monitor before use.Rescue Therapy

[0252] Rescue therapy is any new background therapy or increase in dose above on Day 1 baseline of any permitted therapy given to participants.

[0253] For some rescue medications, IP may be continued after discussion with and approval by the medical monitor. However, if participants receive a prohibited medication as a rescue, they may be discontinued from IP, but stay in the study for safety assessments.

[0254] Rescue medication for worsening DM or ASIM may be administered at the discretion of the Investigators as clinically indicated.

[0255] Although the use of rescue medications is allowable for clinical deterioration, it may be delayed, if possible, through 24 weeks. When offering rescue medication, the medical monitor should weigh the urgency of providing it and the proximity of the primary endpoint (Week 24).

[0256] Participants who receive rescue therapy may be considered treatment failures for subsequent endpoints.

[0257] The date and time of rescue medication administration as well as the name and dosage regimen of the rescue medication may be recorded.Study assessments and procedures• Study procedures and their timing are summarized in Table 3.• Adherence to the study design requirements, including those specified in Table 3, may be required for study conduct.• All screening evaluations may be completed and reviewed to confirm that potential participants meet all eligibility criteria.• Procedures conducted as part of the participant’s routine clinical management and obtained before signing of the ICF may be utilized for screening or baseline purposes provided the procedures met the protocol-specified criteria and were performed within the timeframe defined in Table 3.• In the event of a significant study-continuity issue (e.g., caused by a pandemic), alternate strategies for participant visits, assessments, medication distribution and monitoring may be implemented.• Safety, laboratory, and / or analyte results that could unblind the study may not be reported to investigative sites or other blinded personnel.• Repeat or unscheduled samples may be taken for safety reasons or for technical issues with the samples.Efficacy assessments

[0258] Planned timepoints for all efficacy assessments are provided in Table 3.

[0259] Efficacy may be assessed with:1. Total improvement score (TIS) based on the 6 CSM: a. Health assessment questionnaire-disability index (HAQ-DI) b. Patient Global Disease Activity (PtGDA) c. Physician global disease activity (PhGDA) (part of the myositis disease activity assessment tool [MDAAT]) d. Manual muscle testing 8 (MMT8) bilateral e. Laboratory muscle enzymes f. Extramuscular global assessment (part of the MDAAT)2. Global MDAAT3. Cutaneous dermatomyositis disease area and severity index (CDASI)4. Steroid taper5. Myositis damage index (MDI)6. Myositis functional index 3 (FI3) (optional)7. Forced vital capacity (FVC)8. Handheld dynamometry (optional)9. 28-Joint count10. Actigraphy (optional)11. Magnetic resonance imaging (MRI) scanTIS based on the 6 CSM

[0260] The TIS is derived from standardized clinical response criteria that are recommended for use as primary endpoint in myositis therapeutic. The criteria use the 6 CSM, combining the absolute percentage change in each with varying weights to obtain a TIS on a scale of 0- 100. Different thresholds of improvement have been set for minimal, moderate, and major response. The criteria may be used as a continuous outcome measure, using the TIS, or as a categorical outcome of improvement (minimal, moderate, or major improvement) and thus are a hybrid measure. Improvement category thresholds for minimal, moderate, and major improvement have been developed and validated for DM and PM. (Find online calculator in MRC 2016).

[0261] HAQ-DI

[0262] The HAQ-DI assesses physical function. It comprises 8 sections: dressing and grooming, arising, eating, walking, hygiene, reach, grip, and common daily activities. For each of these categories, participants report the amount of difficulty they have in performing 2 or 3 specific activities. Scoring within each section is from 0 (without any difficulty) to 3 (unable to do). The time frame for the disability questions is the past week. The disability index is designed to assess participants’ usual abilities using their usual equipment.

[0263] PtGDA

[0264] The PtGDA measures the global evaluation by the patient of the patient's overall disease activity at the time of assessment using a 10 cm VAS that ranges from “no evidence of disease activity” to “extremely active or severe disease activity”.

[0265] PhGDA (part of MDAAT)

[0266] The PhGDA is the physician’s judgment of overall disease activity (extramuscular organ systems plus muscle disease activity) based on all clinical laboratory assessments. It uses a 10 cm VAS that ranges from “no evidence of disease activity” to “extreme or maximum disease activity” and a 5 point Likert scale that ranges from 0 (none activity) to 4 (extremely severe activity).

[0267] Participants may be considered to have complete response if, during the study, they have no evidence of disease activity (i.e., PhGDA VAS = 0) while on therapy.

[0268] MMT8 Bilateral

[0269] The MMT8 bilateral is a set of 8 designated muscles tested bilaterally (potential score 0-140). Axial (neck flexors) testing is included, so that potential MMT8 score is 150.

[0270] Laboratory Muscle Enzymes

[0271] The levels of creatine kinase, the transaminases (alanine transaminase [ALT] and aspartate transaminase [AST]), lactate dehydrogenase, and aldolase will be measured to evaluate the effect of Daxdilimab in muscle-associated enzymes.

[0272] Extramuscular Global Assessment (part of MDAAT)

[0273] The extramuscular global assessment provides an overall evaluation for the disease activity in all extramuscular systems (excluding muscle disease activity) using a 10 cm VASthat ranges from “no evidence of disease activity” to “extreme or maximum disease activity”.Global MDAAT

[0274] The MDAAT (V 2.0) measures the degree of disease activity of extramuscular organ systems and muscle combining a 10 cm VAS that ranges from “no evidence of disease activity” to “extreme or maximum disease activity” and an activity index that ranges from 0 (“not present in the last 4 weeks”) to 4 (“new in the last 4 weeks”).CDASI

[0275] The CDASI (V 2.0) is an outcome measure used to assess the severity of cutaneous DM and detect improvement in disease activity. The scale rates disease involvement in 15 different body areas using 3 activity (erythema, scale, erosion / ulceration) and 2 damage (poikiloderma, calcinosis) measures. The presence and severity of Gottron's papules on the hands, periungual changes and alopecia are also captured. The activity score ranges from 0 to 100 and the damage score from 0 to 32. Higher scores indicate greater disease severity.Steroid Taper

[0276] For participants taking corticosteroid (e.g., prednisone or methylprednisone or the like) and who are stable or improving, Investigators will taper their dose 2.5mg / day (prednisone equivalent) every 4 weeks from Week 4 through Week 20 (Table 8). Note that is not permitted to change the corticosteroid dose between Weeks 20 and 24 (FIG. 1).Table 8. Exemplary steroid taper during randomized control period (RCP).

[0277] For participants who remain stable or improving during OLE, Investigators should continue to taper participants off corticosteroids (e.g., prednisone or methylprednisone orthe like) as clinically tolerated. Recommended taper is 2.5 mg / day every 4 weeks until 5 mg / day, then Img / day every 2 weeks until discontinued (Table 9).Table 9. Exemplary steroid taper during open-label extension (OLE).

[0278] If symptoms worsen, participants may hold at current dose or step back up to previous dose.

[0279] Criteria for worsening and holding steroid taper

[0280] If participants are not stable or improving and criteria for worsening (see below) are met, steroid taper may be held.

[0281] Steroid taper may be held if the PhGDA has a global worsening from Baseline by >2 cm on the 10 cm VAS and at least one of the following occurs:• Worsening by > 20% from Baseline on the MMT8 score or• Worsening of the extramuscular global activity by > 2 cm from Baseline on the MDAAT VAS or• Worsening of any 3 of the CSMs by > 30% from Baseline

[0282] Criteria for confirmed worsening and designating treatment unsuccessful, and offering alternative therapy or steroid burst

[0283] The treatment may be considered unsuccessful, and the participant offered an alternative therapy or the steroid taper burst, if on 2 consecutive visits the PhGDA has a global worsening by > 2 cm from Baseline on the 10 cm VAS and at least one of the following occurs (on the same 2 consecutive visits):• Worsening by > 20% from Baseline on the MMT8 score on 2 consecutive visits or• Worsening of the extramuscular global activity by > 2 cm from Baseline on the MDAAT VAS on 2 consecutive visits orWorsening of any 3 of the CSM by > 30% from Baseline on 2 consecutive visitsMDI

[0284] The MDI assesses the degree of disease damage of all organ systems. It is composed of a series of organ-specific questions relating to the presence or absence of a given sign or symptom or problem to measure the extent of damage, and an overall rating of the disease damage of each system using a 10 cm VAS to measure the severity of damage from “no evidence of disease damage” to “extreme or maximum disease damage”.Myositis FI 3

[0285] The myositis FI3 is a functional outcome measure to assess muscle endurance and function of frequently affected muscle groups. Each muscle group is scored as the number of correctly performed repetitions with 60 or 120 maximal number of repetitions depending on muscle group.FVC

[0286] A pulmonary function test in local pulmonary function laboratories may be performed to measure the FVC of the participants.Handheld dynamometry

[0287] A handheld dynamometry may be used to evaluate muscle strength. The procedure has demonstrated strong reliability, construct validity, and responsiveness in myositis patients (Saygin et al, 2021), especially to evaluate strength of single muscle groups (Baschung et al, 2018).28-joint count

[0288] The painful, swollen, and tender Joint count is based on left and right shoulder, elbow, wrist, metacarpophalangeal (MCP)l, MCP2, MCP3, MCP4, MCP5, proximal interphalangeal (PIP)l, PIP2, PIP3, PIP4, and PIP5 joints of the upper extremities, and left and right knee of the lower extremities (Scott et al, 2014). Participants may be asked at the start of the Joint count (prior to assessment of tenderness and swelling) whether they have experienced or are experiencing pain in any of the 28 joints within the last 30 days. Each of the 28 joints will then be evaluated separately for tenderness (by palpating the joint) andswelling. Joints with intra-articular injection within 4 weeks are not evaluable for the assessment.

[0289] The Joint count assessment may include questions regarding limitation of range of movements and effects of joint symptoms on basic and functional activity of daily living.Actigraphy

[0290] To measure change in daily activity, participants may wear an actigraphy device for1 week after each visit. If desired, the actigraphy device can be worn more frequently.Participants should bring the actigraphy device to each visit to allow data downloads.MRI scan

[0291] For participants agreeing to muscle biopsy, a local MRI scan may be used to determine muscle biopsy site.Clinical safety laboratory tests• Laboratory tests (Table 10) will include urinalysis, hematology with differential, a standard chemistry panel (chemistry includes liver function tests), and a serum pregnancy test at Screening for WOCBP.• All protocol-required laboratory tests must be conducted in accordance with Table 3.Table 10. Exemplary laboratory tests.ALP = alkaline phosphatase; ALT = alanine transaminase; AST = aspartate transaminase; PhCG = P-human chorionic gonadotropin; BUN = blood urea nitrogen; FSH = follicle-stimulating hormone; HBcAb = hepatitis B core antibody; HBsAg = hepatitis B surface antigen; HCV Ab = hepatitis C virus antibody; HgAlC = hemoglobin A1C; HIV = human immunodeficiency virus; IEC = Independent Ethics Committee; IFN = interferon; INR = international normalized ratio; IRB = Institutional Review Board; LDH = lactate dehydrogenase; MCH = mean corpuscular hemoglobin; MCV = mean corpuscular volume; RBC = red blood cell; SGOT = serum glutamic- oxaloacetic transaminase; SGPT = serum glutamic-pyruvic transaminase; TB = tuberculosis; ULN = upper limit of normal; WBC = white blood cell a All events of ALT or AST > 3 x ULN and total bilirubin > 2 x ULN (> 35% direct bilirubin) or ALT or AST > 3 x ULN and INR > 1.5 (if INR measured), which may indicate severe liver injury (possible Hy’s law), must be reported to Sponsor in an expedited manner (excluding studies of hepatic impairment or cirrhosis). b If alkaline phosphatase is elevated, consider fractionating. c Urine collection can be postponed for up to 14 days in women with menstrual bleeding or a urinary tract infection at the scheduled visit d As needed in women of childbearing potential or women who are postmenopausal for less than 2 years prior to Screening, have nontherapy-induced amenorrhea for less than 12 months prior to Screening, or are not surgically sterile (absence of fallopian tubes, ovaries and / or uterus). Local urine testing will be standard for the protocol unless serum testing is required by local regulation or IRB / IEC. e The results of an IFN-y release assay (i.e., QuantiFERON-TB Gold Plus or T-SPOT) performed within 12 weeks of the Screening visit (if available) are acceptable, provided there is no reason to suspect any re-exposure. f As needed in women of nonchildbearing potential only These tests do not have to be repeated if performed within 12 weeks prior to Screening (e.g., Rescreening).g Serum virology does not have to be repeated if performed within 12 weeks prior to Screening (e.g., Rescreening).Pregnancy Testing• A serum P human chorionic gonadotropin (phCG) pregnancy test will be performed to all WOCBP by a central laboratory at Screening.• A urine pregnancy test will be performed by study staff at the clinic and prior to the administration of IP from Day 1 through Week 48 and on the End of Study visit (Week 56).Pharmacokinetics

[0292] Serum samples of approximately 3.5 mL (whole blood collection tube) may be collected for measurement of serum concentrations of daxdilimab at the visits and timepoints specified in Table 3.

[0293] Samples may be collected at additional timepoints during the study if warranted and agreed upon between the Investigator and the Sponsor.

[0294] Samples collected for analyses of daxdilimab serum concentration may also be used to evaluate safety or efficacy aspects related to concerns arising during or after the study.

[0295] Intervention concentration information that would unblind the study may not be reported to investigative sites or blinded personnel.Pharmacodynamics

[0296] Planned timepoints for all PD assessments are provided in Table 3.

[0297] It is not possible, at the start of the study, to provide an exhaustive list of biomarkers, as new research within a disease, new information related to daxdilimab, or new analysis techniques may be generated or published while the study is ongoing. However, the effect of daxdilimab on PD biomarkers may be assessed by:• Levels of pDCs in blood (pDC flow cytometry) and tissue (e.g., immunohistochemistry [IHC] on muscle and skin biopsy)• Serum IFN-a• Blood myxovirus resistance protein A (MxA)• Interferon gene signature levels• Peripheral blood mononuclear cells (PBMC)Levels of pDCs in blood and tissue

[0298] The level of circulating pDCs may be measured using multi-parameter flow cytometry on blood.Optional muscle and skin biopsies may be performed at timepoints listed in Table 3 to test whether daxdilimab alters levels of pDCs, inflammatory cells, and / or other biomarkers in tissue.

[0299] Skin biopsy• The biopsy may be performed at Baseline prior to dosing on Day 1 or during the screening period, but not until other screening procedures have confirmed that the participant is eligible for the study.• The sites selected for skin biopsy should have active rash at Baseline.• The biopsy may require one 4 mm punch biopsy and it is recommended that the punch biopsy site is closed with a single suture.• Repeat skin biopsies should be taken from the same anatomic site to the baseline biopsy site avoiding any scar tissue from the previous punch biopsy.• The sample will be formalin-fixed and paraffin-embedded to enable IHC and other analyses.

[0300] Muscle biopsy• Participants agreeing to muscle biopsy may first undergo an MRI scan either on their first or second visit, followed by the muscle biopsy on the same or the following day. These procedures should be performed before dosing. Day 1 visit procedures for these participants may take up to 3 days to be completed. These participants may be dosed one day after biopsy, once recovered. Day 1 will be counted from their first dosing day.• The anatomic site selected for muscle biopsy should be an area with active inflammation on MRI.• For the biopsy, a sample of muscle tissue may be taken by inserting a biopsy needle into the muscle. If a larger sample is required, an incision in the skin (open biopsy) may be made to remove a larger section of muscle.• Repeat muscle biopsies should be taken from the contralateral muscle to the baseline biopsy site.Serum IFN-a

[0301] Serum samples may be collected to assess changes in the levels of cytokines, chemokines, or other proteins (e.g., IFN-a, IL-17, and IFN-y) that may be related to the pathogenesis of DM or ASIM or the mechanism of action of daxdilimab.Blood MxA

[0302] Blood may be collected to assess changes in the level of MxA protein that may be related to the pathogenesis of DM / ASIM or the mechanism of action of daxdilimab.IFN Gene Signature Levels

[0303] Blood may be collected to assess changes in the level of IFN gene signature that may be related to the pathogenesis of DM or ASIM or the mechanism of action of daxdilimab.PBMC

[0304] Peripheral blood mononuclear cells may be collected to monitor changes in the frequency, and possibly gene expression, of immune cell populations in cryopreserved blood leukocytes.Mechanistic / Disease Biomarkers

[0305] Serum may be collected to measure changes in exploratory biomarkers of disease activity, changes in biomarkers related to the mechanism of action of daxdilimab, and changes in biomarkers resulting from daxdilimab administration.

[0306] Specific proteins to be assessed may include, but are not limited to, IFN-a and MxA to measure the effect of daxdilimab on interferon response. These analyses may be performed using both multiplexed assays for panels of biomarkers, as well as individual immunoassays for specific markers of relevance.

[0307] It should be noted that not all assays may be performed for all participants at each time point. Decisions to perform assays may be made based on considerations that include statistical and scientific planning, available technologies, and study outcomes.Metabolomics / Proteomics

[0308] Whole blood samples may be collected and RNA isolated (whole blood transcriptomics in Table 3) to assess changes over time in the expression of genes or gene pathways associated with DM or ASIM, mechanism of action of or in response to daxdilimab administration, or the pathogenesis of DM or ASIM.Skin Swabs

[0309] Skin swabs will be collected to profile the skin microbiome at Baseline and over time to explore associations with clinical responses following daxdilimab treatment.Genetics

[0310] DNA may be isolated from a sample of whole blood collected at Baseline to test for:• Single nucleotide polymorphisms in genes that may be related to the development of DM or ASIM• Fc gamma receptor in genes that may be related to the mechanism of action of daxdilimab.

[0311] In the event of DNA extraction failure, a replacement genetic blood sample may be requested from the participant.Immunogenicity Assessments

[0312] Antibodies to daxdilimab may be assessed by the incidence and titer of ADAs in serum samples collected from all participants according to Table 3.

[0313] Additionally, serum samples may also be collected at the final visit from participants who discontinued IP or were withdrawn from the study.

[0314] Serum samples may be screened for antibodies binding to daxdilimab and the titer of confirmed positive samples may be reported. Other analyses may be performed to verify the stability of antibodies to daxdilimab and / or further characterize the immunogenicity of daxdilimab.

[0315] The detection and characterization of antibodies to daxdilimab will be performed using a validated assay method. Antibodies may be further characterized and / or evaluated for their ability to neutralize the activity of daxdilimab.

[0316] Samples may be stored for a maximum of 15 years (or according to local regulations) following the last participant’s last visit for the study.Quality of Life

[0317] Planned timepoints for all quality of life assessments are provided in Table 3.

[0318] Quality of life may be assessed with:• HAQ-DI and PtGDA (part of TIS)• SF36• Skindexl6 score• PROMIS fatigue 8a• PROMIS physical function 8b• PROMIS pain interference 6a• PROMIS dyspnea severity• Global pain 24-hour NRS• PGIC

[0319] HAQ-DI and PtGDA (part of TIS)

[0320] The HAQ DI and the PtGDA are described as previously disclosed herein.

[0321] SF36

[0322] The SF36 is a health survey that measures functional health and wellbeing from the participant’s perspective with questions that span 8 health domains: physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health.

[0323] Skindexl6 Score

[0324] The Skindexl6 score (Table 11) is used for participants to rate skin conditions that have occurred within the previous week (Atherton et al, 2012; Chren et al, 2001). It is a short 16-item assessment that uses numerical analog scales from 0 (“never bothered”) to 6 (“always bothered”). Responses to the Skindexl6 are categorized into 3 subscales: symptom, emotional, and functional.Table 11. Exemplary Skindexl6 assessment.

[0325] PROMIS Fatigue 8a

[0326] The PROMIS fatigue 8a assess a range of self-reported symptoms, from mild subjective feelings of tiredness to an overwhelming, debilitating, and sustained sense of exhaustion that likely decreases one’s ability to execute daily activities and function normally in family or social roles. Fatigue is divided into the experience of fatigue (frequency, duration, and intensity) and the impact of fatigue on physical, mental, and social activities. All assess fatigue over the past 7 days.

[0327] PROMIS Physical Function 8b

[0328] The PROMIS physical function 8b (V 2.0) measures self-reported capability rather than actual performance of physical activities. This includes the functioning of the participant’s upper extremities (dexterity), lower extremities (walking or mobility), andcentral regions (neck, back), as well as instrumental activities of daily living, such as running errands. The form assesses current function rather than function over a specified period.

[0329] PROMIS Pain Interference 6a

[0330] The PROMIS pain interference 6a (V 1.0) evaluates the consequences of pain on relevant aspects of the participant’s life. This includes the extent to which pain hinders engagement with social, cognitive, emotional, physical, and recreational activities.

[0331] PROMIS Dyspnea Severity

[0332] The PROMIS dyspnea severity evaluates the severity of shortness of breath or difficulty breathing that an adult experiences in response to various specific activities (e.g., dressing oneself without help, preparing meals, walking up 20 stairs).

[0333] Global Pain 24-hour NRS

[0334] The Global pain 24-hour NRS is an 11 -point scale scored from 0 (no pain) to 10 (the most intense pain imaginable). Participants select a value that is most in line with the intensity of pain they have experience in the last 24 hours.

[0335] PGIC

[0336] The PGIC is a categorical scale (Table 12) in which participants are asked to indicate how much their DM or ASIM has changed since they started taking the IP, from ‘much better’ to ‘no change’ to ‘much worse’.Table 12. Exemplary PGIC scale.

[0337] Primary Efficacy Endpoint Analyses

[0338] For both DM and ASIM populations, the estimand of primary interest is defined as follows, using hypothetical strategy to address intercurrent event of rescue medications and treatment policy strategy to address intercurrent event of treatment discontinuation.1. Population: Participants in the Full Analysis Set.2. Variable (endpoint): TIS at Week 24.3. Intercurrent event: a. Rescue medications: The data collected after administration of the rescue medications may be excluded. b. Treatment discontinuation: Participants who discontinue IP before Week 24 may be asked to come to scheduled evaluations until Week 24. The data collected after discontinuation of IP may be included in the analysis.4. Population-level summary: Mean difference between daxdilimab and placebo.

[0339] Within each of the DM and ASIM populations, the primary efficacy endpoint of TIS at Week 24 may be analyzed using a mixed model for repeated measures (MMRM), with treatment, visit, visit by treatment interaction, and randomization stratification factor included in the model.

[0340] Supplementary Analysis of the Primary Efficacy Endpoint

[0341] The supplementary analysis may be performed for the primary efficacy endpoint using treatment policy strategy to address intercurrent event of rescue medications (i.e., including data collected after rescue medications). Additional analysis may be performed. The details will be specified in the SAP.

[0342] Secondary Efficacy Endpoint Analyses

[0343] For both DM and ASIM populations, the estimand for the binary secondary efficacy endpoints is defined as follows, using composite variable strategy to address intercurrent events.1. Population: a. TIS40: Participants in the Full Analysis Set. a. TIS20: Participants in the Full Analysis Set. b. Clinically meaningful oral corticosteroid (OCS) reduction: Participants in the Full Analysis Set with OCS dose > 10 mg prednisone or equivalent at Baseline2. Variable (endpoint): a. TIS40 at Week 24 is defined by meeting the following criteria: i. TIS score > 40 at Week 24 ii. No deterioration at 2 consecutive visits at or prior to Week 24. iii. No use of rescue medications before Week 24. iv. No discontinuation of IP before Week 24. b. TIS20 at Week 24 is defined by meeting the following criteria: i. TIS score > 20 at Week 24. ii. No deterioration at 2 consecutive visits at or prior to Week 24. iii. No use of rescue medications before Week 24.iv. No discontinuation of IP before Week 24. c. Clinically meaningful OCS reduction at Week 24 is defined by meeting the following criteria: i. Either a 25% decrease from Baseline or an OCS dose of 7.5 mg / day of prednisone or equivalent at Week 24. ii. No use of rescue medications before Week 24. iii. No discontinuation of IP before Week 24.3. Intercurrent event: a. Rescue medications: Captured in the variable definition. b. Treatment discontinuation: Captured in the variable definition.4. Population-level summary: Difference in proportions of responders between daxdilimab and placebo.

[0344] Within each of the DM and ASIM populations, the binary secondary endpoints may be analyzed using a logistic regression model with treatment, baseline OCS dose (OCS reduction endpoint only), and randomization stratification factor included in the model.

[0345] For both DM and ASIM populations, the estimand for the continuous secondary efficacy endpoint of change from Baseline to Week 24 in CDASI activity score is similar to the primary estimand, using hypothetical strategy to address intercurrent event of rescue medications and treatment policy strategy to address intercurrent event of treatment discontinuation.

[0346] Within each of the DM and ASIM populations, the change from Baseline to Week 24 in CDASI activity score may be analyzed using a MMRM approach, with treatment, visit, visit by treatment interaction, randomization stratification factor and baseline CDASI activity score included in the model. The missing data may be handled by the MMRM approach.

[0347] Pharmacokinetics analyses

[0348] The PK analysis may be based on the PK Analysis Set. Descriptive statistics of the serum daxdilimab concentration will be tabulated by visit and by treatment group for each of the DM and ASIM populations. Exposure-response (PD, ADA, safety, and efficacy) analysis may be conducted using serum daxdilimab concentration and available drug response data per the Sponsor’s discretion and as the data will allow.

[0349] Pharmacodynamics analyses

[0350] The results of levels of pDCs, serum IFN-a, blood MxA, and IFN gene signature levels, as well as their changes from Baseline, may be summarized descriptively by visit and treatment group using the Safety Analysis Set.

[0351] Immunogenicity analyses

[0352] Number and percentage of participants who develop positive ADA as well as the titer of positive ADA may be summarized by treatment group and by visit for each of the DM and ASIM populations using the Safety Analysis Set.

[0353] Exploratory analyses

[0354] The exploratory endpoints analyses may be detailed in the SAP.Planned Analysis

[0355] Primary Analysis

[0356] The primary analysis may be conducted separately for each of the DM and ASIM populations after the last participant has completed the Week 24 visit or discontinued from study prior to Week 24 for that population. For the primary analysis, all the efficacy and safety data collected prior to the data cut-off will be analyzed.

[0357] Final Analysis

[0358] The final analysis may be conducted separately for each of the DM and ASIM populations after the last participant has completed the study or discontinued early from study for that population.Sample Size Determination

[0359] A sample size of approximately 48 participants (up to approximately 24 participants per treatment group) is planned for each population (DM and ASIM). The sample size was calculated based on the primary efficacy endpoint. Twenty-one participants per treatment group will provide approximately 80% power to detect a mean difference of 20 between daxdilimab and placebo at the 2- sided alpha level of 0.10 using a 2-sample t-test, assuming a standard deviation of 25. The minimum detectable difference is 13 between the daxdilimab group and placebo group. Assuming a drop-out rate of 10% for the first 24 weeks of the study, approximately 24 participants per treatment group will be needed.INCORPORATION BY REFERENCE

[0360] All references, articles, publications, patents, patent publications, and patent applications cited herein are incorporated by reference in their entireties for all purposes. However, mention of any reference, article, publication, patent, patent publication, and patent application cited herein is not, and should not be taken as an acknowledgment or any form of suggestion that they constitute valid prior art or form part of the common general knowledge in any country in the world.

Claims

CLAIMS1. A method of treating dermatomyositis, the method comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigenbinding fragment thereof to a subject in need thereof, wherein the ILT7 antibody or antigenbinding fragment thereof comprises Complementarity -Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg, and wherein the antibody is administered once every 4 weeks.

2. The method of claim 1, wherein the dermatomyositis comprises definite myositis.

3. The method of claim 1, wherein the dermatomyositis comprises probable myositis.

4. A method of treating anti -synthetase inflammatory myositis (ASIM), the method comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigen-binding fragment thereof to a subject in need thereof, wherein the ILT7 antibody comprises Complementarity -Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg, and wherein the antibody is administered once every 4 weeks.

5. The method of claim 4, wherein the ASIM comprises definite myositis.

6. The method of claim 4, wherein the ASIM comprises probable myositis.

7. A method of treating a disease, the method comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigen-binding fragment thereof to a subject in need thereof, wherein the ILT7 antibody comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount comprises a dosage from about 300 mg, and wherein the administering is completed once every 4 weeks.

8. A method of treating a disease, the method comprising administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigen-binding fragment thereof to a subject in need thereof, wherein the ILT7 antibody comprisesComplementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, and wherein the administration is effective in reducing disease as compared to: (a) disease in an otherwise comparable subject lacking the administering; or (b) a baseline measurement of disease in the subject in need thereof.

9. The method of any one of claims 1-8, wherein the administering is continued for at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or up to about 15 administrations.

10. The method of any one of claims 8-9, wherein the administering is effective in reducing disease as compared to (b) the baseline measurement of disease in the subject in need thereof, and wherein the reduction is determined by detecting a reduced total improvement score in the subject.

11. The method of any one of claims 8-9, wherein the administering is effective in reducing disease as compared to (b) the baseline measurement of disease in the subject in need thereof, and wherein the reduction is determined by detecting a reduced level of a symptom of the disease in the subject.

12. The method of any one of claims 10-11, wherein the determination is completed after 6 and / or 12 administrations.

13. The method of any one of claims 10-12, wherein the total improvement score is > 10, 20, 30, 40, or 50.

14. The method of claim 13, wherein the total improvement score is > 20.

15. The method of claim 13, wherein the total improvement score is > 40.

16. The method of any one of claims 11-15, wherein the reduced level of the symptom comprises a reduction in a score of an assessment, as compared to baseline, selected from the group consisting of: Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI), Myositis Disease Activity Assessment Tool (MDAAT), myositis damage index (MDI), and combinations thereof.

17. The method of any one of claims 11-15, wherein the reduced level of the symptom comprises an increase in lung compliance as determined by an increase in forced vital capacity (FVC) as compared to baseline.

18. The method of any one of claims 8-9, wherein the administering is effective in reducing disease as compared to (b) the baseline measurement of disease in the subject in need thereof,and wherein the reduction is determined by a decrease in use of a corticosteroid, and wherein the determination is completed after 6 administrations.

19. The method of claim 18, wherein the corticosteroid comprises prednisone.

20. The method of any one of claims 18-19, wherein the decrease comprises a reduction in frequency of use at least about 10%, 15%, 20%, 25%, 30%, or 40%.

21. The method of any one of claims 18-19, wherein the decrease is from about a > 10 mg / day dosage to a 7.5 mg / day dosage.

22. The method of any one of claims 1-21, wherein the ILT7 antibody comprises a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH and the VL regions comprise an amino acid sequence at least 80% identical to SEQ ID NO: 2 and SEQ ID NO: 7, respectively.

23. The method of any one of claims 1-22, wherein the ILT7 antibody comprises a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH and the VL regions comprise the amino acid sequence of SEQ ID NO: 2 and SEQ ID NO: 7, respectively.

24. The method of any one of claims 1-23, wherein the ILT7 antibody is a monoclonal antibody.

25. The method of any one of claims 1-24, wherein the ILT7 antibody is afucosylated.

26. The method of any one of claims 4-25, wherein a sample of the subject in need is positive for one or more ASIM-associated antibodies.

27. The method of claim 26, wherein the one or more ASIM-associated antibodies is selected from the group consisting of: anti-Jo-1, anti-PL-12, anti-PL-7, anti-KS, anti-EJ, anti- OJ, anti-ZO, and anti-YRS(HA).

28. The method of any one of claims 1-27, wherein the subject in need thereof has a dermatomyositis-related rash.

29. The method of any one of claims 1-28, wherein the disease is effectuated by plasmacytoid dendritic cells.

30. The method of any one of claims 1-29, wherein the administration is effective in reducing a level of a type I interferon in the subject as compared to a baseline level of the subject.

31. The method of claim 30, wherein the level is reduced by at least about 1-fold, 5-fold, 10-fold, 25-fold, 50-fold, 75-fold, 100-fold, 150-fold, or 250-fold.

32. The method of any one of claims 7-31, wherein the administering is effective in eliminating the disease for at least about 3 months, 6 months, 1 year, or 2 years.

33. The method of any one of claims 1-32, wherein the administering is subcutaneous.

34. A method of treating dermatomyositis, the method comprising subcutaneously administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigen -binding fragment thereof to a subject in need thereof, wherein the ILT7 antibody or antigen-binding fragment thereof comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg.

35. A method of treating anti -synthetase inflammatory myositis (ASIM), the method comprising subcutaneously administering an effective amount of an anti-Immunoglobulin-like transcript-7 (ILT7) antibody or antigen-binding fragment thereof to a subject in need thereof, wherein the ILT7 antibody comprises Complementarity-Determining Regions (CDRs) HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 3, 4, 5, 8, 9, and 10, respectively, wherein the effective amount is about 300 mg.

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