Combination treatment of copanlisib and gemcitabine in relapsed refractory PTCL (COSMOS): an open-label phase I/II trial

Background: Current treatment options for peripheral T-cell lymphomas (PTCLs) in the relapsed/refractory setting are limited and demonstrate modest response rates with rare achievement of complete response (CR). Patients and methods: This phase I/II study (NCT03052933) investigated the safety and efficacy of copanlisib, a phosphatidylinositol 3-kinase-alpha/-delta inhibitor, in combination with gemcitabine in 28 patients with relapsed/refractory PTCL. Patients received escalating doses of intravenous copanlisib on days 1, 8, and 15, administered concomitantly with fixed-dose gemcitabine (1000 mg/m(2) on days 1 and 8) in 28-day cycles. Results: Dose-limiting toxicity was not observed in the dose-escalation phase and 60 mg copanlisib was selected for phase II evaluation. Twenty-five patients were enrolled in phase II of the study. Frequent grade >= 3 adverse events (AEs) included transient hyperglycemia (57%), neutropenia (45%), thrombocytopenia, (37%), and transient hypertension (19%). However, AEs were manageable, and none were fatal. The overall response rate was 72% with a CR rate of 32%. Median duration of response was 8.2 months, progression-free survival was 6.9 months, and median overall survival was not reached. Combination treatment produced a greater CR rate in patients with angioimmunoblastic T-cell lymphoma than those with PTCL-not otherwise specified (55.6% versus 15.4%, respectively, P = 0.074) and progression-free survival was significantly longer (13.0 versus 5.1 months, respectively, P = 0.024). In an exploratory gene mutation analysis of 24 tumor samples, TSC2 mutation was present in 25% of patients and occurred exclusively in responders. Conclusion: The combination of copanlisib and gemcitabine is a safe and effective treatment option in relapsed/ refractory PTCLs and represents an important new option for therapy in this rare group of patients.

Automated summary

The combination of copanlisib and gemcitabine showed good safety and efficacy in patients with relapsed/refractory PTCL, with an overall response rate of 72% and a complete response rate of 32%, along with a significant extension in progression-free survival.