Ritumixab Biosimilar Demonstrates Positive Results in Rheumatoid Arthritis

Pharmacokinetics of CT-P10 were highly similar to originator products.

Celltrion presented data at the American College of Rheumatology (ACR) meeting on November 14, demonstrating that its product CT-P10 is as safe and effective as Rituxan for the treatment of rheumatoid arthritis (RA).

In this 24-week, phase 3 randomized trial, investigators tested CT-P10 against both US- and EU-licensed versions of rituximab. The study evaluated pharmacokinetic and pharmacodynamics, as well as safety.

Three hundred seventy-two patients participated in the study. A total of 161 were given CT-P10 and the remainder were given the originator product.

The investigators concluded that the pharmacokinetics of CT-P10 were highly similar to those for the originator products (90% confidence intervals were within the equivalence range of 80% to 125%), and the safety profile was noninferior. Infusion-related reactions occurred in 6 (9.4%) of patients in the biosimilar group, 4 (6.2%) in the US-licensed version of rituximab, and 12 (20%) in the EU-licensed group, and all of these reactions were either grade 1 or 2. Discontinuations as a result of an adverse event occurred in 3.1%, 4.6%, and 1.7% of patients taking the biosimilar, US version, and EU version, respectively.

In a second study on CT-P10 reported at the American College of Rheumatology meeting, a team of researchers sought to gather efficacy data on the biosimilar versus the two licensed versions of Rituxan, using the DAS28-CRP/ESR as a primary endpoint.They found in this phase 3, controlled study, that the biosimilar was therapeutically equivalent to the other treatment groups, with a change in DAS28-CRP of -2.14 for the biosimilar vs. -2.09 for the originator products. Additionally, the change in DAS28-ESR scores were -2.41 vs. -2.35, respectively. ACR 20, 50, and 70 scores were equivalent as well. No significant differences in adverse events were detected among the groups, and no serious complications were reported.

Biosimilar rituximab is being tested not only in patients with RA but in those with non-Hodgkin’s lymphoma (NHL), chronic lymphocytic leukemia (CLL), and polyangiitis. If it is approved for treatment, Celltrion’s product would likely be the first CD20-inhibiting monoclonal antibody to reach the market in a biosimilar version.

Celltrion announced that on November 17, CT-P10 was approved for use in South Korea for non-Hodgkin’s lymphoma, chronic lymphocytic leukemia, and rheumatoid arthritis. It will be marketed under the name Truxima in that country.