A phase 3, randomized study of ofatumumab combined with bendamustine in rituximab-refractory iNHL (COMPLEMENT A + B study).

The standard of care for indolent non-Hodgkin lymphoma (iNHL) is rituximab, an anti-CD20 antibody, with/without chemotherapy. However, multiple relapses are common in these patients. This phase 3, randomized study compared outcomes of a combination of ofatumumab (a second-generation anti-CD20 antibody) and bendamustine, with bendamustine alone in patients unresponsive to prior rituximab-based treatment. Overall, 346 patients were randomized to receive either the combination or bendamustine alone. Bendamustine was given for ≤8 cycles and ofatumumab for ≤12 cycles. The primary end-point was progression-free survival (PFS) after 215 protocol-defined events assessed by independent review committee (IRC). Median IRC-assessed PFS was 16·7 and 13·8 months in the combination and monotherapy arms respectively [hazard ratio (HR) = 0·82; P = 0·1390]. Median overall survival (OS) was 58·2 and 51·8 months in the combination and monotherapy arms respectively (HR = 0·89, P = 0·4968). The safety profile was consistent with previous reports. Overall, 73% and 80% of patients in the combination and monotherapy arms, respectively, experienced a ≥grade 3 adverse event. The study did not meet its primary end-point. No significant improvement in PFS and OS was seen with the combination of ofatumumab and bendamustine as compared with bendamustine alone in rituximab-refractory iNHL (NCT01077518).