FDA Approves the Biosimilar Riabni for Rheumatoid Arthritis

The FDA has approved Amgen’s Riabni (rituximab-arrx), a biosimilar to Biogen’s Rituxan, in combination with methotrexate for adults with moderate-to-severe active rheumatoid arthritis. The FDA in December 2020 approved Riabni for the treatment of adult patients with non-Hodgkin’s lymphoma, chronic lymphocytic leukemia, granulomatosis with polyangiitis (also called Wegener's granulomatosis) and microscopic polyangiitis.

Riabni, CD20-directed cytolytic antibody, is now approved to treat all available Rituxan indications.

In a comparative trial, 311 patients were randomized and treated with Riabni, rituximab RP approved in the European Union (rituximab-EU) or rituximab RP approved in the United States (rituximab-US). The rituximab-US group transitioned to Riabni in period 2 of the study. The primary efficacy endpoint, the change in disease activity score 28 using C-reactive protein (DAS28-CRP) from baseline at week 24, was within the predefined equivalence margin indicating equivalence in clinical efficacy between Riabni and rituximab RP. Safety, pharmacokinetics and immunogenicity of Riabni were similar to rituximab.

Rheumatoid arthritis is an autoimmune and inflammatory disease that mainly attacks the joints. About 1.5 million people in the United States have been diagnosed with rheumatoid arthritis, and out of every 100,000, 71 are diagnosed with RA every year.