A Study of Imvotamab in Active, Refractory Idiopathic Inflammatory Myopathies

A Phase 1b, Open-Label Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Imvotamab in Adult Participants With Active, Refractory Moderate-Severe Idiopathic Inflammatory Myopathies

The purpose of this study is to determine the safety and tolerability of imvotamab in patients with Moderate-Severe Idiopathic Inflammatory Myopathies who have failed prior therapies.

Participants will be given imvotamab through a vein (i.e., intravenously).

This is a Phase 1b, open-label study to determine the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of imvotamab in adult participants with active, refractory, moderate-severe Idiopathic Inflammatory Myopathies. Approximately 5-10 participants will be assigned.

Key Inclusion Criteria:

• Age ≥ 18 years at the time of signing ICF
• Diagnosis of probable or definite IIM according to the 2017 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) classification criteria for IIM with subgroup classification of either DM, polymyositis (PM), anti-synthetase syndrome, or immune-mediated necrotizing myositis (IMNM).
• Active IIM despite treatment with corticosteroids and at least 1 immunosuppressive or immunomodulatory standard-of-care agent determined at the discretion of the investigator after at least 3 months of treatment.
• If using oral corticosteroids (OCS), must be on a stable dose equivalent to ≤ 30 mg/day of prednisone for at least 4 weeks prior to first study treatment

Key Exclusion Criteria:

• Pregnant or breastfeeding or intending to become pregnant during the study or within 3 months after the final dose of imvotamab.
• Receipt of an investigational therapy less than 12 weeks or 5 drug-elimination half-lives (whichever is longer) prior to first administration of study treatment and during the study.
• Has inclusion body myositis or myositis-associated with other connective tissue disease.