FDA Application Withdrawn for Lung Cancer Drug Candidate
Merck and Daiichi Sankyo pulled their submission after the agency found the clinical data insufficient for approval.
Updated on Sept. 26, 2026 in Cancer
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Merck and Daiichi Sankyo have voluntarily withdrawn their application for accelerated FDA approval of the drug ifinatamab deruxtecan. The decision follows feedback from the FDA stating that the existing clinical data package failed to meet the necessary requirements for the proposed lung cancer indication.
Why it matters
This withdrawal highlights the stringent evidence standards the FDA applies to accelerated approval pathways for oncology treatments. It also shifts the timeline for patients who might have relied on this therapy, as the developers must now seek approval through broader, later-stage clinical trials.
In the Phase II IDeate-Lung01 trial, the drug candidate showed a confirmed objective response rate of 48.2% among 137 patients. This preliminary finding was ultimately deemed insufficient by the FDA to support the criteria for accelerated approval.
The players
Merck
A global pharmaceutical company focused on the development of oncology, vaccines, and infectious disease therapies.
Daiichi Sankyo
A pharmaceutical company specializing in oncology, with a significant portfolio of antibody-drug conjugate treatments.
The details
Ifinatamab deruxtecan is an antibody-drug conjugate designed to target and deliver therapy directly to cancer cells. The FDA’s decision was based on an evaluation of the IDeate-Lung01 clinical data package, which failed to meet the regulatory thresholds for this specific accelerated pathway. The development program has faced previous challenges, including a temporary pause in a Phase III trial due to instances of interstitial lung disease.
Timeline
December 2025: Enrollment in the IDeate-Lung02 trial was paused due to safety concerns.
January 2026: The clinical hold on the IDeate-Lung02 trial was lifted.
September 25, 2026: Merck and Daiichi Sankyo withdrew their FDA submission.
Health Landscape
This development reflects the evolving regulatory landscape surrounding oncology drug approvals, where the FDA is increasingly demanding robust data packages to ensure clinical efficacy. It underscores the challenges inherent in moving antibody-drug conjugates through the accelerated approval pathway toward standard use.
If you or a loved one are currently navigating lung cancer treatment options, this news confirms that ifinatamab deruxtecan is not currently an available or FDA-approved choice. These updates are a good reason to speak with your oncologist about established, evidence-based therapies that are currently available to you.
The takeaway
The withdrawal of this application reminds patients and providers that clinical trial data must consistently meet high regulatory benchmarks before a drug reaches the clinic. Always discuss the latest clinical trial developments with your oncologist to determine which established therapies are appropriate for your specific diagnosis.
Further reading
For more on the current research and development of oncology treatments, visit the Cancer section.
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