Abexinostat monotherapy in R/R FL: Phase II study results

Results from a multicenter, single-arm, phase II trial (NCT03934567) evaluating abexinostat, a histone deacetylase (HDAC) inhibitor, in patients with relapsed/refractory (R/R) follicular lymphoma (FL; N = 90) were published in Signal Transduction and Targeted Therapy by Gui et al. The primary endpoint was the independent review committee (IRC)-assessed objective response rate (ORR). Secondary endpoints included disease control rate (DCR), duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety.

Key data: In the full analysis set (FAS; n = 82), at a median follow-up of 30.6 months, the ORR was 69.5% (95% confidence interval [CI], 58.4–79.2), with 14.6% of patients achieving a complete response (CR). Reduction in tumor size was observed in 89% of patients. The IRC-assessed DCR was 91.5% (95% CI, 83.2–96.5) and the median DoR was 14.0 months (95% CI, 9.2–not reached [NR]). The median PFS and OS were 13.8 months (95% CI, 9.7–30.3) and 47.2 months (95% CI, 45.7–NR), respectively. Grade 3/4 treatment-emergent adverse events (TEAEs) included thrombocytopenia (42.2%), neutropenia (25.6%), leukopenia (7.8%), lymphopenia (5.6%), hypokalemia (5.6%), diarrhea (4.4%), and anemia (4.4%). Overall, 24.4% of patients experienced a serious adverse event (SAE).

Key learning: Abexinostat demonstrated promising efficacy and a manageable safety profile in patients with heavily pretreated R/R FL, supporting its potential as a third-line or later treatment option.