FDA reviewers endorse Celltrion's Rituxan biosimilar ahead of panel vote

Celltrion’s biosimilar to Roche’s blockbuster Rituxan has already been rejected at the FDA once for manufacturing problems, but in the company’s second attempt, agency staffers have reacted favorably to the med. In a review document (PDF) posted ahead of an FDA panel meeting set for Wednesday, internal reviewers found no “clinically meaningful differences … in terms of safety, purity and potency” between the biosim and Roche drug.

The FDA’s Oncologic Drugs Advisory Committee will meet on Wednesday to consider Celltrion’s application after the FDA rejected the biosimilar last year. If the biosim wins approval, Celltrion could potentially launch this year; Roche has disclosed that its U.S. patent protections for cancer and rheumatoid arthritis blockbuster Rituxan expire in 2018. For this review, Celltrion is only seeking approvals to treat certain patients with non-Hodgkin's lymphoma.

Even if the FDA’s panel endorses Celltrion’s biosimilar, that doesn’t guarantee an approval. The agency typically follows committee votes, but it doesn't have to.

Roche’s Rituxan brought in more than $4 billion in the U.S. last year, topping FiercePharma’s 2018 report of top drugs susceptible of biosim or generic competition. Earlier this year, the drugmaker caught a break when a Novartis biosimilar suffered an FDA rejection. At the time, a Deutsche Bank analyst wrote that Rituxan could dodge biosim competition until next year. 

Celltrion already has an FDA-approved biosimilar to Johnson & Johnson’s Remicade, plus two other biosims approved in Europe. The company is now seeking nods for its biosimilars to Rituxan and Herceptin after manufacturing problems caused FDA rejections.

In January, the FDA issued a warning letter related to plant failures in South Korea, triggering the rejections. In May, Celltrion said it “has made progress addressing the concerns ... and is committed to working with the agency to fully resolve all outstanding issues with the highest priority and urgency.” The company refiled the submissions and at the time said it expects both FDA approvals yet this year. Under a partnership, Teva is set to market Celltrion’s Rituxan biosimilar in the U.S. 

For Roche, potential biosim competition to its top med comes as no surprise. The company has been bracing for competition to a trio of its top blockbusters that annually bring in more than $20 billion. Over the next few years, Rituxan, Herceptin and Avastin will come under increasing biosim competition.