A Study to Investigate the Efficacy, Safety, and Pharmacokinetics of Oral Rilzabrutinib Compared With Placebo in Participants 18 Years of Age and Older With Warm Autoimmune Hemolytic Anemia

This is a parallel-group, Phase 3, double-blind, 2-arm study to investigate the efficacy, safety, PK and PD of oral rilzabrutinib in achieving durable Hb response (DHR) compared with placebo in approximately 90 male and female participants ≥ 18 years of age with a confirmed diagnosis of primary wAIHA. Following a 4-week screening period, eligible participants will be randomized in a 2:1 ratio to receive rilzabrutinib or placebo in primary analysis period (PAP) for a duration of up to 24 weeks. All participants who completed PAP will then continue in open-label period (OLP) to receive rilzabrutinib for a duration of 28 weeks. Upon the completion of OLP, only participants who demonstrate Hb increase during the last 8 weeks of OLP per specified criteria in the protocol will be eligible to continue in long-term extension (LTE) of the study. The duration of the LTE period will be from the first-participant-in (FPI)-LTE until the last participant completes 52 weeks in LTE. The safety follow-up period of this study following treatment completion or discontinuation will be 2 weeks.