Otsuka Holdings said on 2 October that its wholly owned subsidiary Taiho began submitting a new drug application to the US Food and Drug Administration on 1 October, US time. The application covers zipalertinib combined with platinum-based chemotherapy in previously untreated, locally advanced or metastatic non-small cell lung cancer with an EGFR exon 20 insertion mutation.
What the filing adds
The efficacy case was already public from the earlier trial results. The new step is regulatory. Taiho is using the FDA's Real-Time Oncology Review programme, which lets a company submit clinical trial data before the full application is complete so that review of efficacy and safety data can start early. Otsuka expects the submission to be complete by the end of 2026.
The application rests on the Phase III REZILIENT3 trial. At a planned interim analysis, the zipalertinib-plus-chemotherapy arm showed a statistically significant and clinically meaningful extension of progression-free survival over chemotherapy alone, meeting the primary endpoint.
A second application already under review
A separate application for zipalertinib alone is already with the FDA. It covers locally advanced or metastatic disease in patients who have had platinum-based chemotherapy, and its Prescription Drug User Fee Act target date is 27 February 2027. The notice gives no target date for the combination application. Zipalertinib is still in development and has not been approved by any country's or region's regulator.
Taiho and its subsidiary Taiho Oncology develop the drug. In the US, they work with Cullinan Therapeutics, Inc.
Why Otsuka cares
Otsuka calls zipalertinib one of the product groups it expects to drive future growth, and describes the filing as important progress toward raising corporate value over the medium to long term. It left its consolidated forecast for the year ending December 2026 unchanged.
The patient pool is narrow. The notice cites literature putting EGFR exon 20 insertions at up to 4% of non-small cell lung cancer worldwide. In the US, about 16% of such patients carry an EGFR mutation, and exon 20 insertions make up as much as 12% of those. The notice gives no sales estimate.