Merck and Daiichi Sankyo Withdraw BLA for Ifinatamab Deruxtecan in Extensive-Stage Small Cell Lung Cancer
核心洞察
Merck and Daiichi Sankyo voluntarily withdrew their BLA for ifinatamab deruxtecan in extensive-stage small cell lung cancer (搜索) after FDA discussions found the data insufficient for accelerated approval.
The application, which had an Oct. 10, 2026 action date after priority review, rested on Phase 2 IDeate-Lung01 data that did not meet accelerated approval requirements.
Enrollment continues in the Phase 3 IDeate-Lung02 trial comparing the B7-H3 (搜索)-directed antibody-drug conjugate with physician's choice chemotherapy after one prior platinum line.
Merck & Co. (搜索) and Daiichi Sankyo have voluntarily withdrawn their Biologics License Application for ifinatamab deruxtecan in extensive-stage small cell lung cancer (搜索), after discussions with the FDA concluded that the submitted data do not satisfy the requirements for accelerated approval of the proposed indication.
The application had been granted priority review in April and carried an Oct. 10, 2026 action date. It sought accelerated approval for adults whose extensive-stage small cell lung cancer (搜索) had progressed on or after platinum-based chemotherapy. The companies said the supporting dataset, including results from the Phase 2 IDeate-Lung01 trial, did not meet the requirements for accelerated approval.
"While we are disappointed that the current dataset are not supportive of an approval at this time, we are continuing to evaluate the role of ifinatamab deruxtecan in patients with extensive-stage small cell lung cancer (搜索) and other types of difficult-to-treat cancer," said Marjorie Green, head of oncology at Merck Research Laboratories.
Phase 2 Dose-Finding Data
IDeate-Lung01 enrolled 187 patients across Asia, Europe and North America. Its dose-optimization stage randomized patients between two dose levels of ifinatamab deruxtecan, followed by a single-dose expansion stage. The primary endpoint was objective response rate by blinded independent central review, and the trial did not include a chemotherapy control arm.
An interim analysis published Sept. 7, 2024 reported a 54.8 percent response rate among 42 patients receiving the selected higher dose, compared with 26.1 percent among 46 patients in the lower-dose group. Those figures describe a dose study, while the priority-review application later rested on the trial's primary analysis and a separate early-stage study.
The older dataset also recorded grade 3 or higher treatment-emergent adverse events in 50.0 percent of higher-dose recipients as of April 25, 2024. The lower-dose group included one treatment-related fatal case of interstitial lung disease. The Sept. 25 release did not identify a particular safety finding as the reason for withdrawal.
Ongoing Phase 3 Program
Merck and Daiichi Sankyo continue to enroll patients in the randomized Phase 3 IDeate-Lung02 trial, which compares ifinatamab deruxtecan with physicians' choice of amrubicin, lurbinectedin or topotecan after one previous line of platinum chemotherapy. The companies said enrollment is nearing completion but gave no data readout date and no new filing timetable.
"Enrollment into the IDeate-Lung02 Phase 3 trial is near completion and we look forward to assessing the potential for a future filing of ifinatamab deruxtecan with the FDA and other global regulatory authorities based on those results," said Abderrahmane Laadem, Daiichi Sankyo's head of therapeutic area oncology development.
Two other Phase 3 trials of the candidate are under way, in castration-resistant prostate cancer (搜索) and esophageal squamous cell carcinoma (搜索). Ifinatamab deruxtecan is a B7-H3 (搜索)-directed antibody-drug conjugate being jointly developed by the two companies across several cancer types.
Competitive Landscape in the Same Setting
Amgen said in a Nov. 19, 2025 release that the FDA granted full approval to Imdelltra for adults with extensive-stage small cell lung cancer (搜索) after progression on or after platinum chemotherapy. Its randomized Phase 3 trial showed median overall survival of 13.6 months, compared with 8.3 months for chemotherapy. Imdelltra targets DLL3 (搜索), while ifinatamab deruxtecan targets B7-H3 (搜索).