FDA Accepts BLA for Pembrolizumab Biosimilar Candidate FYB206

The FDA will review FYB206, an investigational biosimilar candidate referencing pembrolizumab (Keytruda), after accepting its biologics license application (BLA), marking the first publicly announced acceptance of a filing for a pembrolizumab biosimilar, according to a news release from Zydus Lifesciences and Formycon.¹

The application was sent to the FDA in the third quarter of 2026. The Biosimilar User Fee Amendments (BsUFA) set a 12-month goal from submission to completed review, made up of a filing review lasting as long as 60 days followed by a 10-month substantive review. On that schedule, a regulatory decision could come in the third quarter of 2027, and a regulatory dossier has also been filed with Health Canada, according to the companies.

Formycon reached an agreement with the FDA in February 2025 that a comparative phase 3 efficacy trial would not be required for the program.

“We developed FYB206 on a path agreed with the FDA, without conducting a comparative [p]hase [3] efficacy trial. This enabled us to accelerate the program and substantially reduce development investment while maintaining the rigorous scientific standards required for biosimilar approval,” Stefan Glombitza, CEO of Formycon AG in Planegg-Martinsried, Germany, stated in the news release.

Clinical Development Pathway

The companies disclaimed that that regulators have not established biosimilarity as of this announcement. Under the streamlined strategy agreed upon with the FDA, Formycon aimed to establish therapeutic comparability with the reference product through analytical characterization combined with pharmacokinetic (PK) data, according to an earlier news release from the company.²

In February 2026, Formycon reported that its pivotal Dahlia study (NCT06551064), a randomized, double-blind, multicenter trial, met its primary objective by showing PK equivalence between FYB206 and pembrolizumab in the adjuvant melanoma setting. The study enrolled patients with resected stage II or III melanoma, excluding ocular or uveal melanoma.³ Approximately 96 patients were assigned to receive FYB206 or Keytruda, both at 200 mg administered as an intravenous infusion over 30 minutes on day 1 of each cycle. The primary PK outcomes were area under the concentration curve for 1 dosing interval at cycle 1 (21 days) and cycle 6 (126 days).

Pembrolizumab, an immune checkpoint inhibitor that blocks the PD-1 receptor, is indicated across numerous tumor types and is reported to be the top-selling biologic worldwide.¹ Merck’s key compound patent for pembrolizumab in the United States expires in December 2028, with expiration in 2031 in the European Union, in 2032-2033 in Japan, and 2028 in China.⁴

Sharvil P. Patel, managing director of Zydus Lifesciences Limited in Ahmedabad, India, described the acceptance as a step toward broader access to pembrolizumab in North America. “As demand for high-quality, accessible oncology treatments continues to rise, FYB206 has the potential to improve patient access and outcomes while strengthening our oncology biosimilars portfolio,” Patel stated in the news release.¹

REFERENCES

1. Zydus and Formycon: FYB206 becomes first publicly announced Keytruda® biosimilar accepted for review by USFDA. News release. Zydus Lifesciences; Formycon. October 13, 2026. Accessed October 14, 2026. https://tinyurl.com/3hy9xm8u

2. Formycon announces positive clinical data for Keytruda® biosimilar candidate FYB206 (pembrolizumab). News release. Formycon. February 25, 2026. Accessed October 14, 2026. https://tinyurl.com/32zjcm5v

3. Assessment of PK similarity of FYB206 in comparison with Keytruda in resected stage II or III melanoma patients. ClinicalTrials.gov. Updated September 4, 2026. Accessed October 14, 2026. https://clinicaltrials.gov/study/NCT06551064

4. Merck & Co., Inc. Annual report on form 10-K for the fiscal year ended December 31, 2025. US Securities and Exchange Commission. Accessed October 14, 2026. https://tinyurl.com/24fuc9jk