FDA Slaps BioNTech-MediLink ADC With Partial Clinical Hold Due to ‘Significant Risk of Illness’


Pictured: Sign outside BioNTech's building in Germany/iStock, U. J. Alexander

The FDA has slapped a partial clinical hold on BioNTech and MediLink’s Phase I study of an antibody-drug conjugate candidate for types of non-small cell lung cancer or breast cancer, following multiple patient deaths. The German biotech announced the hold Monday in an SEC filing

The antibody-drug conjugate (ADC) is being tested as a later-line treatment option for patients with heavily pre-treated advanced or metastatic EGFR-mutated non-small cell lung cancer (NSCLC) or HR+/HER2-negative breast cancer. The hold prevents enrollment of new U.S. patients in the trial, according to BioNTech.

BioNTech’s partner MediLink, who is sponsoring the open-label trial, said the FDA cited concerns that higher doses of BNT326 may expose patients to “unreasonable and significant risk of illness or injuries.” MediLink has paused enrollment to review clinical and safety data, including observed grade 5 adverse events resulting in death.  

The trial abstract, shared late last month at the 2024 American Society of Clinical Oncology annual meeting, included a safety profile of “adequate safety and tolerability.” 

By design, ADCs are intended to target cancer cells more precisely than chemotherapy to avoid damage to healthy cells. In the 52 participants in the dose escalation trial, BioNTech reported one grade 3 dose limiting toxicity event at the highest dosing group—febrile neutropenia. Additional treatment-related adverse events included anemia, nausea, fatigue and decreased white blood cell, neutrophil, lymphocyte and platelet counts.  

Among the 46 evaluable patients, the companies reported one complete response, 16 partial responses and 26 patients with stable disease.  

The ADC candidate is being developed by the partners in a research collaboration announced in October 2023 that is worth potentially over $1 billion. BioNTech has been teaming recently with other companies to expand its cancer pipeline as sales of its COVID-19 vaccine continue to wane. 

Kate Goodwin is a freelance life science writer based in Des Moines, Iowa. She can be reached at kate.goodwin@biospace.com and on LinkedIn.   

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