Study of Novel Regimens in Relapsed or Refractory Multiple Myeloma

Study of EOS884448 Alone, and in Combination with Iberdomide with or Without Dexamethasone, in Participants with Relapsed or Refractory Multiple Myeloma

This is a multicenter, open-label, phase I/II clinical study, to assess the safety, tolerability, antitumor activity, pharmacokinetics and pharmacodynamics of EOS884448 (also known as EOS-448 or GSK4428859A), alone or in combination with iberdomide with and without dexamethasone in participants with relapsed/refractory multiple myeloma (RRMM).

Inclusion Criteria:

• All participants must have a documented diagnosis of relapse/refractory Multiple Myeloma and have measurable disease as defined per IMWG criteria.
• All participants must have received at least 3 prior lines of MM therapy with IMiD, PI and Anti-CD-38, and progressed on their last therapy (prior BCMA targeted therapy allowed).
• All participants must have Eastern Cooperative Oncology Group (ECOG) Performance Status of 0,1or 2.
• All participants must have adequate organ function.
• Females of childbearing potential (FCBP) or male participant must agree to follow contraception requirements.

Exclusion Criteria:

• All participants with non-secretory MM
• All participants with known auto-immune disease
• All participants with history of life-threatening toxicity related to prior immune therapy.
• All participants with active graft versus host disease after allogeneic stem cell transplantation.
• All participants with active, unstable cardiovascular function.
• All participants with active infection requiring systemic therapy.
• All participants with hypersensitivity to any of the treatments.
• All participants with any active gastrointestinal dysfunction that prevents the patient from swallowing tablets or interferes with absorption of study treatment.