A Phase 2 Study of Obexelimab in Patients with Relapsing Multiple Sclerosis

Prior treatment

• Has received treatment with intravenous immunoglobulins, plasmapheresis or natalizumab (patients who stop getting infusions within 6 months prior to randomization should be ruled out for progressive multifocal leukoencephalopathy) within 2 months prior to randomization. Has received sphingosine 1-phosphate receptor modulator treatment within 5 half-lives of the treatment or until the end of its pharmacodynamic activity, or whichever is longer, prior to randomization (for example; Ponesimod [Ponvory®]: 2 weeks, Siponimod [Mayzent®]: 1 month, Fingolimod [Gilenya®]: 2 months, Fingolimod oral disintegrating tablets [ODT] [Tascenso ODT®]: 2 months, Ozanimod [Zeposia®]: 3 months)
• Has received treatment with B-interferons or glatiramer acetate within 1 month prior to randomization
• Has received cladribine, cyclophosphamide, alemtuzumab, or mitoxantrone within 2 years prior to randomization
• Relapse in the 30 days prior to randomization
• Has received an investigational treatment or direct medical intervention on another clinical study within 12 weeks or < 5 half-lives of the investigational treatment, whichever is longer prior to randomization
• Prior use of B cell–depleting agents
• Has received treatment with teriflunomide within 3 months to randomization (unless elimination procedure was done)
• History of drug or alcohol abuse in the previous 12 months before screening in the opinion of the investigator
• Prior use of other biologic immunomodulatory agents ≤ 6 months prior to randomization
• Has received live vaccine, live-attenuated vaccine, or live therapeutic infectious agent within the 4 weeks prior to randomization
• Has received lymphoid irradiation or stem cell transplantation
• Has received systemic corticosteroids or adrenocorticotropic hormone within 1 month (30 days) prior to screening MRI
• Has received azathioprine or methotrexate within 6 months prior to randomization
• Has received dimethyl fumarate within 1 month prior to randomization

Other illness

• Hypersensitivity to dextran or components of dextran or any component of the study drug and placebo, including excipients
• Malignancy within 5 years except successfully treated in situ cervical cancer, resected squamous cell carcinoma, or basal cell carcinoma of the skin
• Acute hepatitis B infection (hepatitis B surface antigen-positive), active hepatitis C virus, or HIV infection. Patients will be excluded from the study if they have a positive test for active hepatitis B through detection of (a) hepatitis B surface antigen or (b) hepatitis B core antibody. Patients with active, chronic, or uncured HBV will be excluded.
• Meet criteria for neuromyelitis optica spectrum disorder
• History or evidence of a clinically unstable/uncontrolled disorder, condition, or disease (including, but not limited to, cardiopulmonary, oncologic, renal, hepatic, metabolic, hematologic, psychiatric, active infection) other than RMS that, in the opinion of the investigator, would pose a risk to patient safety or interfere with the study evaluation, procedures, or completion
• Any known allergy to mAb therapy
• Evidence of active tuberculosis (TB) or at high risk for TB as shown by at least one of the following: a. Documented history of active TB or latent TB, unless completion of treatment according to local guidelines b. Positive, indeterminate, or invalid interferon-gamma release assay results at screening, unless treatment is documented. Patients with an indeterminate test result can repeat the test once either centrally or locally, but if the repeat test is also indeterminate, the patient is excluded c. Signs or symptoms that could represent active TB d. Chest radiograph, computed tomography, or MRI that suggests possible diagnosis of TB
• History of Gilbert’s syndrome

Lab values

• Hematology or clinical chemistry parameters that meet any of the following criteria at screening: a. White blood cell count < 3.5 × 10^3/μL b. Absolute neutrophil count < 1.5 × 10^3/μL c. Elevated serum creatinine > 2.5 × upper limit of normal (ULN) OR estimated creatinine clearance < 40 mL/min calculated by the Cockcroft-Gault formula at screening d. Hemoglobin < 10 g/dL e. Platelet count < 75 × 10^3/μL
• Abnormal liver function tests meeting any of the following criteria: a. Alanine aminotransferase > 2 × ULN b. Aspartate aminotransferase > 2 × ULN c. Total bilirubin > 1.5 × ULN

Age

• ≥ 10 years disease duration from onset with patient’s EDSS ≤ 2.0 (patient reported is adequate in absence of written medical record)

Other

• Primary progressive MS or inactive secondary progressive MS
• Inability to comply with MRI scanning or MRI contrast administration
• Has > 20 Gd+ lesions on brain MRI at screening

• Capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the ICF
• Male or female, ≥ 18 to ≤ 60 years of age, inclusive, at the time of signing the ICF
• Diagnosis of RMS (relapsing-remitting or active secondary progressive) according to the 2017 revision of the McDonald diagnostic criteria
• An EDSS of ≤ 5.5 at the Screening Visit
• Must have documentation of: a. at least 1 relapse within the previous year OR b. ≥ 2 relapses within the past 2 years OR c. ≥ 1 active Gd-enhancing brain lesion on an MRI scan within the past 6 months prior to screening
• A female patient is eligible to participate if she is not pregnant, not breastfeeding, and at least 1 of the following conditions applies: a. Not a woman of childbearing potential (WOCBP) as defined in Appendix 4 OR b. A WOCBP who agrees to follow the contraceptive guidance in Appendix 4 until at least 8 weeks after the last administration of IMP AND c. Has a negative serum pregnancy test at screening and a negative urine pregnancy test at Day 1 prior to the first dose of IMP AND d. Agrees to refrain from egg donation until at least 8 weeks after the last administration of IMP
• A male patient must: a. Agree to either (i) abstain from intercourse or (ii) use contraception (as detailed in Appendix 4) until at least 8 weeks after the last administration of IMP, or (iii) be surgically sterile for the duration of the study AND b. Agree to refrain from donating sperm until at least 8 weeks after the last administration of IMP