Eligible pts were ≥18 years old, had pathologically confirmed MCL with documented cyclin D1 overexpression or t(11;14) translocation…The ORR (95% CI) was 68.5% (58.9–77.1) for all pts and 70.1% (58.6–80.0) for the DG (Table 1); CRR (95% CI) was 17.6% (10.9–26.1) for all pts and 15.6% (8.3–25.6) for the DG. Among all treated pts with complete or partial response, 89.2% of responses occurred at the first disease assessment. Median (95% CI) DOR was 13.7 (9.0–19.9) months for all pts and 12.1 (9.0–not estimable) months for the DG. Median (95% CI) PFS was 11.99 (8.3–16.9) months for all pts and 13.6 (10.0–16.9) months for the DG. Parsaclisib monotherapy demonstrated a rapid and durable response, had an acceptable safety profile, and was generally well tolerated in BTK inhibitor–naive pts with R/R MCL.