BioNTech SE's (NASDAQ:BNTX) partner MediLink Therapeutics (Suzhou) Co., Ltd says the FDA has placed a partial clinical hold on the Phase 1 trial.

The MediLink-sponsored trial evaluates the early-stage antibody-drug conjugate product candidate BNT326/YL202 as a later-line treatment in heavily pre-treated patients with advanced or metastatic epidermal growth factor receptor-mutated non-small cell lung cancer or HR+/HER2-negative breast cancer.

The partial hold affects the enrollment of new patients in the trial in the U.S., BioNTech said in an SEC filing.

The FDA has shared with MediLink concerns that BNT326/YL202 may, at higher doses, expose human subjects to an unreasonable and significant risk of illness or injuries.

Certain steps need to be taken to address the FDA requests, including reviewing clinical and safety data, sharing available pharmacological data with the Agency, and providing additional information in the investigators' brochure regarding the safety findings, including grade 5 adverse events observed in studies YL202-INT-101-01 and YL202-CN-201-01.

MediLink has taken actions to pause enrollment of new patients in the U.S. and address the FDA requirements.

Price Action: BNTX shares are down 5.04% at $87.44 at last check Monday.