Ofatumumab Fails to Meet Primary Endpoint in Head-to-Head Comparison With Rituximab
No difference in progression-free survival in lymphoma patients
A phase III study of ofatumumab (Arzerra, GlaxoSmithKline/Genmab) plus chemotherapy versus rituximab (Rituxan, Genentech/Biogen Idec) plus chemotherapy to treat patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) did not meet its primary endpoint as there was no statistically significant difference in progression-free survival (PFS) between the two treatment arms.
Moreover, no differences were observed in adverse events (AEs) leading to treatment discontinuation, in grade-3 or greater AEs, in severe adverse events (SAEs), or in fatal SAEs between the treatment arms. However, more dose interruptions and delays occurred because of infusion reactions and increased serum creatinine levels in the ofatumumab-plus-chemotherapy arm.
The pivotal phase III, randomized ORCHARRD trial included 447 patients who were refractory to, or had relapsed after, first-line treatment with rituximab in combination with a chemotherapy regimen containing anthracycline or anthracenedione, and were eligible for autologous stem-cell transplant (ASCT). The patients were randomly assigned to receive three cycles of either ofatumumab or rituximab in combination with DHAP (dexamethasone, cytarabine and cisplatin) salvage chemotherapy. After the third treatment cycle, patients who achieved a complete or partial response received high-dose chemotherapy followed by ASCT. The study’s primary endpoint was PFS.
Ofatumumab — a human monoclonal antibody that targets an epitope on the CD20 molecule, encompassing parts of the small and large extracellular loops — is indicated in combination with chlorambucil for the treatment of previously untreated patients with chronic lymphocytic leukemia (CLL) for whom fludarabine-based therapy is considered inappropriate. The drug is also indicated for the treatment of patients with CLL that is refractory to fludarabine and alemtuzumab. Ofatumumab is not approved or licensed anywhere in the world for the treatment of DLBCL.
DLBCL is the most common form of non-Hodgkin lymphoma (NHL), and is an aggressive (fast-growing) lymphoma or cancer of the B-cells. DLBCL is the most common lymphoid malignancy in adults, accounting for 30% of all NHL in the Western world. Approximately 38,000 new cases of DLBCL occur annually in the U.S., Japan, and the five major European markets.