A Phase 3 Randomized, Open-Label Clinical Study to Evaluate the Efficacy and Safety of Pembrolizumab plus Epacadostat, Pembrolizumab Monotherapy, and the EXTREME Regimen as First line Treatment for Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma (KEYNOTE-669/ECHO-304)

Status

Completed

Phases

Phase 3

Study type

Interventional

Source

EU CTIS

Registry ID

CTIS2024-512015-47-00

Acronym

MK-3475-669

Enrollment

Registered

2024-06-11

Start date

2018-01-09

Completion date

2025-10-30

Last updated

2025-03-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Histologically or cytologically-confirmed Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma that is considered incurable by local therapies

Brief summary

Objective Response Rate (ORR) of Pembrolizumab + Epacadostat, Pembrolizumab Monotherapy and the EXTREME Regimen

Detailed description

Safety and Tolerability of Pembrolizumab + Epacadostat Versus Pembrolizumab Versus the EXTREME Regimen as Measured by Number of Participants Experiencing Adverse Events (AEs), Safety and Tolerability of Pembrolizumab + Epacadostat Versus Pembrolizumab Versus the EXTREME Regimen as Measured by Number of Participants Discontinuing Study Treatment Due to AEs

Interventions

DRUGKEYTRUDA 25 mg/mL concentrate for solution for infusion

DRUGEpacadostat

DRUGCETUXIMAB

DRUGCISPLATIN

DRUGCARBOPLATIN

DRUGFLUOROURACIL

Eligibility

Sex/Gender

All

Age

18 Years to No maximum

Design outcomes

Primary

Measure	Time frame
Objective Response Rate (ORR) of Pembrolizumab + Epacadostat, Pembrolizumab Monotherapy and the EXTREME Regimen	—

Secondary

Measure	Time frame
Safety and Tolerability of Pembrolizumab + Epacadostat Versus Pembrolizumab Versus the EXTREME Regimen as Measured by Number of Participants Experiencing Adverse Events (AEs), Safety and Tolerability of Pembrolizumab + Epacadostat Versus Pembrolizumab Versus the EXTREME Regimen as Measured by Number of Participants Discontinuing Study Treatment Due to AEs	—

Countries

Portugal, Spain

Outcome results

None listed

Source: EU CTIS · Data processed: Feb 4, 2026