Pixantrone plus rituximab versus gemcitabine plus rituximab in patients with relapsed aggressive B-cell non-Hodgkin lymphoma not eligible for stem cell transplantation: a phase 3, randomized, multicentre trial (PIX306).

PIX306 was a phase 3, randomised, single-blind, multicentre trial conducted in adult patients with diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma (FL) grade 3 who relapsed after ≥1 rituximab-containing regimen and were not eligible for a stem cell transplant. Patients were randomised 1:1 to pixantrone 50 mg/m2 or gemcitabine 1000 mg/m2 on days 1, 8 and 15 of a 28-day cycle, combined with rituximab 375 mg/m2 on day 1, for up to six cycles. Patients were followed for up to 96 weeks. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), complete response (CR) rate, overall response rate (ORR) and safety. Overall, 312 patients were randomised (median age 73·0 years). The study did not meet its primary endpoint. Median PFS [95% confidence interval (CI)] was 7·3 months (5·2-8·4) with pixantrone + rituximab (PIX + R) and 6·3 months (4·4-8·1) with gemcitabine + rituximab [GEM + R; hazard ratio (HR): 0·85; 95% CI 0·64-1·14; P = 0·28]. Median OS was 13·3 (10·1-19·8) months with PIX + R and 19·6 (12·4-31·9) months with GEM + R (HR: 1·13; 95% CI 0·83-1·53). ORR was 61·9% and 43·9% respectively and CR rate 35·5% and 21·7%. The incidence of adverse events, including cardiac events, was not statistically significant different between PIX + R and GEM + R.