Multinational phase 2 trial of parsaclisib for relapsed or refractory follicular lymphoma

Parsaclisib is a potent and highly selective PI3Kδ inhibitor, with clinical benefit in patients with relapsed or refractory (R/R) B-cell malignancies. The multinational phase 2 CITADEL-203 trial evaluated parsaclisib for R/R follicular lymphoma (FL). The objective response rate was 77.7% with complete response in 19.1%. The median time to response was 8.1 weeks; median duration of response was 14.7 months; median progression-free survival was 15.8 months; and median overall survival was not reached. Dose interruption, reduction, and discontinuation due to treatment-emergent adverse events occurred in 46.8%, 17.5%, and 23.8% of patients, respectively. The authors conclude that among patients with R/R FL, treatment with parsaclisib resulted in rapid and durable responses, with a manageable safety profile.