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# Clinical Hold on Lung Cancer Trial After Deaths
- URL: https://www.fdaweb.com/clinical-hold-on-lung-cancer-trial-after-deaths/
- Published: 2025-12-18T12:00:00.000Z
- Updated: 2026-09-14T15:29:32.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5160417

A pivotal lung cancer trial of ifinatamab deruxtecan has been placed on a global clinical hold after reports of treatment-related deaths from lung toxicity, dealing a fresh setback to antibody-drug conjugates that use Daiichi Sankyo’s deruxtecan payload, according to a [report](https://www.oncologypipeline.com/apexonco/lung-toxicity-deaths-halt-ifinatamab?ref=fdaweb.com) on ApexOnco (*oncologypipeline.com).* The Phase 3 Ideate-Lung02 study was halted after regulators were notified of a higher-than-expected incidence of Grade 5 interstitial lung disease events, according to entries on the EU clinical trials registry. The trial is evaluating ifinatamab deruxtecan, a B7-H3–targeting ADC jointly developed by Daiichi Sankyo and Merck & Co, in patients with post-platinum small-cell lung cancer.

Daiichi Sankyo confirmed the status to ApexOnco, saying the study is “currently on global hold.” Merck said the FDA’s action followed a voluntary pause initiated by Daiichi, and added that the hold does not affect other studies of the drug.

The development underscores the persistent safety concerns surrounding deruxtecan-based ADCs, particularly the risk of interstitial lung disease. Merck licensed ifinatamab deruxtecan from Daiichi in 2023 as part of a broad ADC partnership that included $5.5 billion in upfront payments and R&D funding across multiple programs.

Ifinatamab deruxtecan is one of three pivotal trials in Merck and Daiichi’s collaboration. The other phase 3 studies — Ideate-Prostate01 and Ideate-Esophageal01 — remain open and recruiting, according to U.S. and EU trial registries. Ideate-Lung02, however, was advanced largely on Phase 2 data that had already hinted at dose-related toxicity issues, including treatment discontinuations due to ILD, though no ILD-related deaths were reported at that stage, ApexOnco reported.

The setback follows earlier trouble for another Daiichi–Merck ADC, patritumab deruxtecan, whose U.S. filing collapsed after a confirmatory trial failed to show an overall survival benefit and revealed treatment-related deaths, including from ILD.

ILD has also complicated the broader Daiichi ADC portfolio, including drugs partnered with AstraZeneca. Enhertu carries a boxed warning for ILD and pneumonitis in the U.S., while Datroway was approved this year with a non-boxed ILD warning after repeated regulatory scrutiny over both lung toxicity and lack of consistent survival benefit.

More recently, one of Datroway’s Phase 3 trials, Tropion-Lung15, was temporarily halted across seven EU countries due to an increase in high-grade ILD cases, according to the EU trials registry. That study, in EGFR-mutated non-small cell lung cancer, is testing Datroway alone or in combination with Tagrisso against chemotherapy and has been listed as “active, not recruiting” since September.