# Ifinatamab deruxtecan (I-DXd) PDUFA Event: Previously treated extensive-stage small cell lung cancer

Canonical URL: https://biopharmsignal.com/pdufa-calendar/MRK/ifinatamab-deruxtecan-previously-treated-es-sclc

Ticker: MRK

Company: Merck

Event date: 2026-10-10

Event type: FDA Decision

Stage: PDUFA

Result: Pending

Application type: BLA

FDA decision expected. FDA assigned an October 10, 2026 PDUFA target action date to the I-DXd BLA.

## Event Timeline

### October 10, 2026 — FDA decision expected

FDA assigned an October 10, 2026 PDUFA target action date to the I-DXd BLA.

[Merck — BLA acceptance and PDUFA date](https://www.merck.com/news/ifinatamab-deruxtecan-granted-priority-review-in-the-u-s-for-adult-patients-with-previously-treated-extensive-stage-small-cell-lung-cancer-who-experienced-disease-progression-on-or-after-platinum-bas/)

### April 13, 2026 — FDA accepted the BLA with Priority Review

FDA accepted the application based on the Phase 2 IDeate-Lung01 and Phase 1/2 IDeate-PanTumor01 trials and placed it in the Real-Time Oncology Review and Project Orbis programs.

[Merck — BLA acceptance and Priority Review](https://www.merck.com/news/ifinatamab-deruxtecan-granted-priority-review-in-the-u-s-for-adult-patients-with-previously-treated-extensive-stage-small-cell-lung-cancer-who-experienced-disease-progression-on-or-after-platinum-bas/)

### September 7, 2025 — Pivotal IDeate-Lung01 results were presented

The Phase 2 trial showed a confirmed objective response rate of 48.2% and a median response duration of 5.3 months in previously treated ES-SCLC.

[Merck — IDeate-Lung01 results at WCLC 2025](https://www.merck.com/news/ifinatamab-deruxtecan-demonstrated-clinically-meaningful-response-rates-in-patients-with-extensive-stage-small-cell-lung-cancer-in-ideate-lung01-phase-2-trial/)

### August 2025 — FDA granted Breakthrough Therapy designation

FDA granted Breakthrough Therapy designation for the same previously treated ES-SCLC population covered by the BLA.

[Merck — I-DXd regulatory designations and IDeate-Lung01 results](https://www.merck.com/news/ifinatamab-deruxtecan-demonstrated-clinically-meaningful-response-rates-in-patients-with-extensive-stage-small-cell-lung-cancer-in-ideate-lung01-phase-2-trial/)

### March 9, 2022 — Phase 2 IDeate-Lung01 study started

The pivotal study began evaluating ifinatamab deruxtecan in patients with pretreated extensive-stage small-cell lung cancer.

[ClinicalTrials.gov — IDeate-Lung01 study record (NCT05280470)](https://clinicaltrials.gov/study/NCT05280470)

## Regulatory Designations

- Priority Review FDA: [Merck — BLA acceptance and Priority Review](https://www.merck.com/news/ifinatamab-deruxtecan-granted-priority-review-in-the-u-s-for-adult-patients-with-previously-treated-extensive-stage-small-cell-lung-cancer-who-experienced-disease-progression-on-or-after-platinum-bas/)

- Breakthrough Therapy FDA: [Merck — I-DXd regulatory designations and IDeate-Lung01 results](https://www.merck.com/news/ifinatamab-deruxtecan-demonstrated-clinically-meaningful-response-rates-in-patients-with-extensive-stage-small-cell-lung-cancer-in-ideate-lung01-phase-2-trial/)

- Orphan Drug FDA: [Merck — BLA acceptance and regulatory designations](https://www.merck.com/news/ifinatamab-deruxtecan-granted-priority-review-in-the-u-s-for-adult-patients-with-previously-treated-extensive-stage-small-cell-lung-cancer-who-experienced-disease-progression-on-or-after-platinum-bas/)

## Related Pages

- MRK PDUFA calendar: https://biopharmsignal.com/pdufa-calendar/MRK.md

- MRK company profile: https://biopharmsignal.com/company/MRK.md

- PDUFA calendar: https://biopharmsignal.com/pdufa-calendar.md