FDA Rejects Summit Therapeutics’ Ivonescimab, Blocking US Launch of PD-1xVEGF Drug Class
By Dr. Zubair Khalid, DVM, MS, PhD ·
The U.S. Food and Drug Administration has issued a complete response letter to Summit Therapeutics, halting the immediate commercial arrival of ivonescimab in the United States. The decision derails the domestic debut of a drug class that many industry leaders believe could eventually challenge Merck & Co.’s blockbuster immunotherapy Keytruda.
Ivonesscimab is a bispecific antibody that targets both PD-1 and VEGF, combining two established cancer-fighting mechanisms in a single molecule. The FDA’s rejection means the drug will not enter the U.S. market for now, delaying a potential competitor to Keytruda, which generated more than $25 billion in sales last year.
The PD-1xVEGF class has drawn heavy interest across the biotech sector because it aims to improve upon checkpoint inhibitors by simultaneously blocking tumor immune evasion and angiogenesis. Success of such a combination could reshape standard treatment for multiple cancers, particularly non-small cell lung cancer, where Keytruda is widely used.
While the complete response letter does not specify the exact reasons for rejection, it typically indicates that the FDA has identified deficiencies in the application that must be resolved before approval can proceed. The setback for Summit Therapeutics also raises questions about the regulatory path for similar bispecific antibodies in development at other companies.
Source: FDA rejects Summit’s ivonescimab, derailing US arrival of much-hyped PD-1xVEGF class