The Keytruda biosimilar FDA review has formally begun. On 13 October 2026, Formycon and Zydus Lifesciences announced that the US Food and Drug Administration has accepted the Biologics License Application (BLA) for FYB206, their proposed biosimilar to Keytruda (pembrolizumab). The companies say it is the first publicly announced FDA acceptance of a Keytruda biosimilar application, to their knowledge, and that a decision could come in the third quarter of 2027. FYB206 is investigational and has not been approved by any regulator.
Keytruda is one of the best-selling medicines in the world, so any credible challenger draws attention. This report explains what acceptance means, how FYB206 was developed without a large comparative efficacy trial, who holds which rights, and what remains unknown.
Keytruda biosimilar FDA review: the key facts
- What happened: the FDA accepted the FYB206 BLA for review.
- Submitted: the BLA was filed in the third quarter of 2026.
- Possible decision: the third quarter of 2027, under the FDA’s biosimilar review goals.
- US and Canada rights: Zydus will commercialise FYB206; Formycon develops, files and supplies.
- Canada: the dossier has also been submitted to Health Canada.
- Status: investigational, with no marketing approval and no claim that biosimilarity has been established by regulators.
What FDA acceptance means for the Keytruda biosimilar FDA review
Acceptance means the agency has judged the application complete enough to begin a full scientific review. It is a procedural milestone. It is not an approval, and it says nothing about whether FYB206 will be found highly similar to Keytruda. Under the Biosimilar User Fee Amendments (BsUFA), the FDA aims to finish its work within 12 months of submission, made up of up to 60 days to decide whether to file the application and about 10 months of substantive review. That is where the third-quarter 2027 date comes from, and the companies themselves say a decision “could” arrive then, not that it will.
Approval would also not mean an immediate launch. The companies say commercialisation is subject to regulatory approval and to the resolution of any intellectual property issues. The release gave no details of Keytruda patents or exclusivity, so we cannot say when a launch could happen even if the FDA says yes. More on the review process is on FDA’s biosimilars pages.
How FYB206 reached the Keytruda biosimilar FDA review
The notable point is what was left out. Formycon says it agreed with the FDA in February 2025 that a comparative Phase 3 efficacy trial would not be needed. Instead, the development relied on a detailed analytical and functional comparison with the reference product plus a pivotal pharmacokinetic study named Dahlia, which met its primary objective in February 2026 and showed pharmacokinetic equivalence. Clinical development finished in July 2026.
Formycon estimates that skipping the Phase 3 study saves investment in the “high double-digit million euro range”, a company figure we have not verified. The approach also fits the FDA’s direction of travel: in October 2025, the agency issued draft guidance proposing that comparative efficacy trials generally would no longer be required for therapeutic protein biosimilars. Draft guidance is not final policy, and the FDA will decide FYB206 on its own evidence. The release did not say whether FYB206 is an intravenous or subcutaneous product.
Zydus and Formycon: who does what in the Keytruda biosimilar FDA review
In December 2025 the companies signed an exclusive licensing and supply agreement for the US and Canada. Formycon completes development, prepares and files the dossiers and supplies the product. Zydus commercialises it in both markets. Formycon keeps global rights and shares in gross profits from its commercial partners. FDA acceptance triggers a milestone payment from Zydus to Formycon, whose amount was not disclosed. Formycon also names MS Pharma for the Middle East and North Africa and Lotus for parts of Asia-Pacific, with talks continuing for Europe, Latin America and other regions.
For India’s pharmaceutical sector, the story is notable because an Indian drugmaker is a named commercial partner on a first-of-its-kind US filing in oncology. We have followed Zydus before, including its saroglitazar Phase 3 data in a rare liver disease, and the wider biosimilars market in our report on the US launch of the FILKRI biosimilar. More coverage is in our pharmaceutical section.
Why the Keytruda biosimilar FDA review matters commercially
A biosimilar is a biological medicine shown to be highly similar to an already approved reference product, with no clinically meaningful differences in safety or effectiveness. It is not the same as a generic of a chemical drug, because biologics are made in living cells and cannot be copied exactly. The companies put worldwide Keytruda sales, including its subcutaneous version, at $31.7 billion in 2025 and $16.4 billion in the first half of 2026. Doubling the half-year figure gives about $32.8 billion, which is our own crude run-rate and not a forecast. Pembrolizumab blocks the PD-1 immune checkpoint and is used in many cancers, so a lower-priced alternative could eventually affect a very large market.
The release also cites IQVIA data that 118 biologics with $232 billion in US sales will lose exclusivity by 2034, while only 12 have a biosimilar in development. If that holds, the Keytruda biosimilar FDA review is an early test of how quickly the biosimilar industry can move into oncology.
What we still do not know about the Keytruda biosimilar FDA review
- Whether other companies have filed and have not announced it, since the claim is “publicly announced” only.
- The patents and exclusivity that could shape a launch date.
- Whether FYB206 targets the intravenous product, the subcutaneous product or both.
- The milestone payment amount and the economics for Zydus.
- Whether the FDA will ask for more data during review.
Our assessment of the Keytruda biosimilar FDA review
In our assessment, the acceptance is a real milestone for both companies but a modest one in regulatory terms. The big tests, the FDA’s decision on similarity and the legal path to market, are still ahead. The development route without a comparative efficacy trial will be watched by the whole industry, because a positive outcome could shorten timelines and lower costs for other biosimilars. Dates in this process are goals, not guarantees: the FDA can ask for more information during review, which can extend the timeline, and the companies would be expected to disclose any change to the third-quarter 2027 outlook.
Frequently asked questions
Has the Keytruda biosimilar FDA review approved FYB206?
No. The FDA has accepted the application for review. The product is investigational.
When could the Keytruda biosimilar FDA review finish?
A decision could come in the third quarter of 2027, according to the companies.
Who will sell FYB206 in the US?
Zydus holds the commercialisation rights for the United States and Canada, subject to approval and resolution of any IP issues.
What is the active ingredient?
Pembrolizumab, the molecule in Keytruda.
Is FYB206 the first Keytruda biosimilar?
It is the first with a publicly announced FDA acceptance, according to the companies. It is not approved.
How we reported this: we relied on the Formycon and Zydus joint announcement of 13 October 2026. We did not review the BLA. Figures labelled as ours are our own calculations. Last updated: 13 October 2026. This article is news reporting and not investment or medical advice.
[…] Pembrolizumab alone is already a standard first-line option for PD-L1-positive recurrent or metastatic head and neck cancer, so a new treatment needs to beat it, not simply match it. For more on pembrolizumab, see our report on the first Keytruda biosimilar application accepted by the FDA. […]