Formycon and Zydus Lifesciences announced on October 13 that the FDA has accepted for review the biologics license application for FYB206, a proposed biosimilar to Merck’s Keytruda (pembrolizumab). To the best of the companies’ knowledge, it is the first publicly announced acceptance by the FDA of a filing for a Keytruda biosimilar. The application was submitted in the third quarter of 2026, and the same dossier has also been submitted to Health Canada.
Two features of the program stand out. First, FYB206 was developed without a comparative Phase 3 efficacy trial, on a pathway the companies agreed with the FDA in early 2025. That lowers the cost and time of biosimilar development materially, and it reflects the agency’s broader move to accept analytical and pharmacokinetic evidence in place of large clinical studies for well-characterized biologics. Second, the commercial split is already set: Zydus holds exclusive commercialization rights for the United States and Canada, and the acceptance triggers a milestone payment to Formycon under their licensing agreement.
On timing, the companies note that under the Biosimilar User Fee Amendments the FDA aims to complete review within 12 months of submission, which points to a possible decision in the third quarter of 2027. Acceptance is not approval, and for a product of Keytruda’s scale the binding constraint is usually patents, not review speed. Merck’s core Keytruda patents run toward 2028, and biosimilar launches against protected biologics are typically settled or litigated to a date rather than launched at approval.
Read with today’s patent-wave story, the filing is the leading edge of that 2028 exposure becoming concrete. Merck is defending Keytruda with lifecycle work, including its subcutaneous version, at the same time as the first biosimilar applicant enters the review queue. For payers and oncology practices, the practical question for 2027 is not whether a biosimilar is approved, but what launch date the patent process produces.