Credit: Linda Bartlett
The European Commission (EC) has expanded the indication for the anti-CD20 monoclonal antibody ofatumumab (Arzerra).
The EC granted conditional approval for ofatumumab in combination with chlorambucil or bendamustine to treat patients with chronic lymphocytic leukemia (CLL) who have not received prior therapy and are not eligible for fludarabine-based therapy.
In 2010, the EC granted ofatumumab conditional approval to treat CLL patients who are refractory to fludarabine and alemtuzumab.
Ofatumumab received conditional approval because the drug’s benefits appear to outweigh the risks it poses. Ofatumumab will not receive full approval until the drug’s developers, GlaxoSmithKline and GenMab, submit results of additional research to the EC.
Trial results
The EC’s new approval of ofatumumab, for previously untreated CLL patients, is based on results from 2 trials, COMPLEMENT 1 and OMB115991.
The phase 3 COMPLEMENT 1 trial was a comparison of ofatumumab plus chlorambucil (n=221) with chlorambucil alone (n=226) in CLL patients for whom fludarabine-based treatment was considered inappropriate.
In this study, ofatumumab plus chlorambucil improved progression-free survival compared to chlorambucil alone. The median times were 22.4 months and 13.1 months, respectively, and the hazard ratio was 0.57 (P<0.001).
In the phase 2 trial known as OMB115991, researchers evaluated ofatumumab in combination with bendamustine in 44 patients with previously untreated CLL for whom fludarabine-based treatment was considered inappropriate.
The combination elicited an overall response rate of 95% and a complete response rate of 43%.
The overall safety profile of ofatumumab in CLL (previously untreated and relapsed/refractory) is based on data from 511 patients in clinical trials.
This includes 250 patients with relapsed/refractory CLL who were treated with ofatumumab alone and 261 patients with previously untreated CLL who were treated in combination with an alkylating agent.
The most common adverse effects associated with ofatumumab were infusion reactions, neutropenia, anemia, febrile neutropenia, thrombocytopenia, leukopenia, lower respiratory tract infection (including pneumonia), upper respiratory tract infection, sepsis (including neutropenic sepsis and septic shock), herpes virus infection, and urinary tract infection.
