Nov 15 (Reuters) – The US Food and Drug Administration on Sunday declined to approve Summit Therapeutics’ lung cancer drug ivonescimab, a setback for efforts to expand treatment for patients whose cancer has progressed after earlier therapies.
In its so-called complete response letter, the FDA cited a late-stage trial showing that, while ivonescimab significantly delayed disease progression, it did not demonstrate a statistically significant improvement in overall survival.
The decision follows the drug’s failure to achieve statistical significance on overall survival, a key measure of long-term treatment benefit, in a late-stage study that formed part of Summit’s marketing application.
The agency concluded that the progression-free survival benefit alone did not support a favorable benefit-risk profile for approval.
The FDA’s decision was based on a late-stage study in which ivonescimab, combined with chemotherapy, reduced the risk of disease progression or death by 48%, compared with chemotherapy alone. However, the primary analysis did not show a statistically significant improvement in overall survival, or OS, which measures how long patients live after starting treatment. Summit later submitted updated survival data to the FDA that it said showed consistent improvement across Asian and Western patients.
Summit has argued that longer follow-up supports the drug’s benefit, citing updated analyses that pointed to a lower risk of death across Western and Asian patient subgroups.
The “subsequently matured OS dataset, consistency between Western and Asian patients, lack of new safety signals, and management’s previously characterized constructive regulatory interactions strengthen the package versus the original analysis,” TD Cowen analysts said earlier this month.
Ivonescimab is designed to block two proteins: PD-1, which helps cancer evade the immune system, and VEGF, which tumors use to grow blood vessels, helping the immune system better find and attack cancer cells.
Summit acquired rights to ivonescimab in the United States, Canada, Europe and Japan from China’s Akeso in 2022 under a deal valued at up to $5 billion. Akeso retained rights in China and other markets.
AstraZeneca said in September it would invest $2 billion in Summit and collaborate on studies combining ivonescimab with its antibody-drug conjugate cancer therapies.
Other approved treatments for the condition include Johnson & Johnson’s chemotherapy-free treatment combination with Rybrevant and AstraZeneca’s Tagrisso. Summit is expected to report late-stage data from a separate study in patients with a different type of lung cancer by year-end.
(Reporting by Padmanabhan Ananthan, Mariam Sunny, and Rishabh Jaiswal in Bengaluru; Editing by Tasim Zahid and Christina Fincher)
