Rituximab Biosimilar Proves Equivalence as Monotherapy in Follicular Lymphoma

CT-P10 (Truxima™, Celltrion Healthcare), a biosimilar to anti-CD20 antibody rituximab, was therapeutically equivalent and had a similar safety profile to rituximab when given as a monotherapy in patients with low tumor burden follicular lymphoma, according to the results of a phase III, double-blind trial presented at the 60th ASH Annual Meeting and Exposition.

In the study, 258 patients with low tumor burden follicular lymphoma were randomly assigned to receive CT-P10 or rituximab (375 mg/m² intravenously) as monotherapy weekly for 4 weeks as induction therapy, followed by maintenance therapy every 2 months for 2 years. To be eligible for maintenance therapy, patients had to achieve complete response, unconfirmed complete response, partial response, or stable disease after induction therapy.

The majority of patients on both arms completed up to 7 months of treatment—119/130 (92%) of those assigned CT-P10 and 112/128 (88%) assigned rituximab. The primary endpoint for this portion of the trial was overall response rate (ORR) over 7 months, and was similar in both treatment arms. Patients assigned to CT-P10 had an ORR of 83.1% compared with 81.3% for rituximab.

CT-P10 was also well tolerated, according to study researcher Michinori Ogura, MD, PhD, of Kasugai Municipal Hospital in Konan, Japan, and colleagues. Both agents had a similar safety profile, and the researchers observed no new safety findings. Adverse event rates were 71% with CT-P10 and 67% with rituximab. Infections and infusion-related reactions occurred in a similar proportion of patients in both groups, and no patients experienced progressive multifocal leukoencephalopathy or hepatitis B virus reactivation.

On November 28, the U.S. Food and Drug Administration approved CT-P10 as the first biosimilar to rituximab for the treatment of adult patients with CD20-positive, B-cell non-Hodgkin lymphoma (NHL) to be used as a single agent or in combination with chemotherapy. In February 2017, the European Medicines Agency approved it for use in all indications for which rituximab is approved, including follicular lymphoma, diffuse large B-cell NHL, chronic lymphocytic leukemia, rheumatoid arthritis, granulomatosis with polyangiitis, and microscopic polyangiitis.