The PI3K-delta inhibitor zandelisib can produce a high overall response rate (ORR) in patients with relapsed/refractory follicular lymphoma (FL), according to research presented at the EHA 2022 Hybrid Congress.
Longer follow-up is needed to determine the duration of response and long-term safety of zandelisib in this patient group, according to study presenter Wojciech Jurczak, MD, PhD, of Maria Sklodowska Curie National Research Institute of Oncology in Krakow, Poland.
Dr Jurczak presented results from the FL cohort of the phase 2 TIDAL trial (ClinicalTrials.gov Identifier: NCT03768505). The cohort included adults with grade I-IIIA FL who had received 2 or more prior therapies, including an anti-CD20 antibody and an alkylating agent but not a prior PI3K inhibitor.
Patients received zandelisib at 60 mg daily for the first 2 cycles. After that, they received intermittent dosing on days 1 to 7 of each 28-day cycle. Patients were treated until intolerance or disease progression.
There were 121 patients who received intermittent dosing. Their median age at baseline was 64 (range, 31-87) years. Patients had received a median of 3 prior therapies (range, 2-8), and 95.9% had previously received chemoimmunotherapy.
A total of 91 patients were evaluable for efficacy. The ORR was 70.3%, with 35.2% of patients having a complete response. The disease control rate was 85%.
Dr Jurczak said the efficacy of zandelisib was “exemplary,” but the follow-up is not long enough to accurately measure the duration of response. The median follow-up was 9.4 months.
All 121 patients were included in safety analysis. The most common adverse events (AEs) were diarrhea (33%), neutropenia (26%), and nausea (19%). Discontinuations due to treatment-related AEs were reported in 9.9% of patients.
Grade 3 AEs of special interest occurring in more than 1 patient included diarrhea (4.9%), rash (3.3%), stomatitis (2.5%), and colitis (1.7%). There were no grade 4 AEs of special interest.
Fatal treatment-emergent AEs included 4 cases of COVID-19, 1 case of pneumonia, and 1 case of tumor lysis syndrome.
Disclosures: This research was supported by MEI Pharma. The presenter declared affiliations with MEI Pharma, AstraZeneca, Beigene, Janssen-Cilag, Lilly, Roche, Takeda, AbbVie, Sandoz-Novartis, and TG Therapeutics.
Zelenetz A, Jurczak W, Ribrag V, et al. Efficacy and safety of zandelisib administered by intermittent dosing (ID) in patients with relapsed or refractory (R/R) follicular lymphoma: Primary analysis of the global phase 2 study TIDAL. Presented at EHA 2022; June 9-12, 2022. Abstract S208.