Multinational phase 2 trial of duvelisib for peripheral T-cell lymphoma: final results of PRIMO

Dr. Neha Mehta-Shah

Duvelisib is an oral dual inhibitor of the PI3K-δ and PI3K-γ isoforms. The multinational phase 2 PRIMO trial evaluated duvelisib monotherapy for relapsed or refractory peripheral T-cell lymphoma (R/R PTCL) and found promising activity and acceptable safety. Final results of PRIMO have now been published. PRIMO was conducted in 2 phases (dose optimization and dose expansion) at 45 centers globally. Eligible patients were ≥ 18 years of age, had histologically confirmed diagnosis of PTCL, and had received at least 2 cycles of one standard regimen for PTCL. Based on the dose optimization results, the selected regimen for dose expansion (n=123) was 75 mg BID for 2 cycles (to maximize disease control) followed by 25 mg BID (to reduce late toxicities) continued until progressive disease or unacceptable toxicity. The Independent Review Committee-assesed objective response rate was 48.0%, the complete response rate was 33.3%, the median duration of response was 7.9 months, the median progression-free survival was 3.4 months, and the median overall survival was 12.4 months. In the AITL subgroup, the ORR was 62.2%, the CRR was 51.4%, the mDOR was 11.3 months, the mPFS was 8.3 months, and the mOS was 18.1 months. Treatment-emergent adverse events of any grade occurred in 97.6%, grade ≥ 3 in 74.0%, resulting in dose hold in 44.7%, and resulting in dose reduction in 9.8%. The authors conclude that duvelisib had significant activity and tolerability in patients with R/R? PTCL, most notably in the AITL subgroup.