Zydus and Formycon's Keytruda Biosimilar Becomes the First Publicly Announced One Accepted for US FDA Review

India's Zydus Lifesciences and its German partner Formycon say the US Food and Drug Administration (FDA) has accepted for review the Biologics License Application (BLA) for FYB206, their proposed biosimilar to Merck's blockbuster cancer drug Keytruda (pembrolizumab). The companies announced the acceptance on 13 October 2026. To their knowledge, it is the first publicly announced FDA acceptance of a Keytruda biosimilar application.

This is not yet an approval. But it puts an India-partnered biologic at the front of the queue for one of the most valuable drug markets in the world.

Why Keytruda matters

Pembrolizumab is an immune-checkpoint inhibitor. It is a monoclonal antibody that blocks the PD-1 receptor on immune cells, which lets the immune system recognise and attack tumours. It is approved across a long list of cancers and has become one of the world's best-selling medicines. Indian trade press describes FYB206 as targeting a market worth about US$31 billion. As key patents on the originator approach expiry, biosimilar makers are racing to be among the first to launch.

What the companies announced

• The BLA was submitted in the third quarter of 2026.
• Under the US biosimilar user-fee programme (BsUFA), the FDA aims to finish its review within about 12 months, including up to 60 days of filing review. That points to a decision around the third quarter of 2027.
• FYB206 was developed without a comparative Phase III efficacy trial, on a development path the companies say was agreed with the FDA in early 2025. Instead of a large outcomes trial, biosimilarity is shown mainly through detailed analytical comparison and clinical pharmacology studies.
• Zydus holds exclusive commercialisation rights for the US and Canada, and the dossier has also been filed with Health Canada. Coverage notes that the FDA acceptance triggers a milestone payment to Formycon.

The "first" claim comes from the companies themselves. Other developers may have filed applications without announcing them.

The partnership model

Formycon is a German biosimilar developer. Its model is to develop molecules and license them out to commercial partners in individual regions. Zydus brings commercial reach in North America and its own experience of building a biologics portfolio. For Indian companies, partnerships of this kind are a common route into regulated markets for complex biologics: they share the development risk and give access to the US market without building the entire pipeline alone. If FYB206 succeeds, it will strengthen Zydus's position as a commercial partner of choice for complex biosimilars aimed at the US.

Why this matters for Indian biotech

India built its pharmaceutical reputation on small-molecule generics. Biologics are much harder to copy: they are large proteins made in living cells, and showing that a copy is "highly similar" needs advanced analytical science, cell-line development and tightly controlled manufacturing. Indian companies such as Biocon, Intas, Dr. Reddy's and Zydus have spent more than a decade building those capabilities. A complex oncology antibody like pembrolizumab is near the top of that ladder.

The FDA's willingness to review a biosimilar without a comparative efficacy trial also points to a wider shift in regulation that could lower development costs. That would favour companies with strong analytical and manufacturing capability, which is where India's biosimilar makers have been investing.

What comes next

During the review the FDA will look at the analytical package, clinical pharmacology data and manufacturing facilities. Patent disputes with the originator, which are common for blockbuster biologics, may decide the launch date as much as the approval does. If FYB206 is approved and launched, it could give an Indian company early access to a very large US market.

Sources

• Zydus Lifesciences — NSE press release, 13 October 2026
• PR Newswire — Zydus and Formycon: FYB206 becomes first publicly announced Keytruda biosimilar accepted for review by USFDA
• BioPharm International — FDA accepts BLA for Formycon and Zydus' FYB206
• Medical Dialogues — Zydus, Formycon hit major USFDA milestone for first USD 31 billion Keytruda biosimilar
• BioSpectrum India — Zydus unveils first publicly announced acceptance by USFDA of Keytruda biosimilar application
• Targeted Oncology — FDA accepts BLA for pembrolizumab biosimilar FYB206