A Phase 3 Study of Pembrolizumab + Epacadostat or Placebo in Subjects With Unresectable or Metastatic Melanoma (Keynote-252 / ECHO-301)

August 21, 2025 updated by: Incyte Corporation

A Phase 3 Randomized, Double-Blind, Placebo-Controlled Study of Pembrolizumab (MK-3475) in Combination With Epacadostat or Placebo in Subjects With Unresectable or Metastatic Melanoma (Keynote-252 / ECHO-301)

The purpose of the study is to assess the efficacy, safety, and tolerability when combining pembrolizumab with epacadostat or placebo in participants with unresectable or metastatic melanoma

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

706

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Australia
    • New South Wales
      • Camperdown, New South Wales, Australia
      • Westmead, New South Wales, Australia
      • Wollstonecraft, New South Wales, Australia
    • Queensland
      • Cairns, Queensland, Australia
      • Greenslopes, Queensland, Australia
    • South Australia
      • Kurralta Park, South Australia, Australia
    • Victoria
      • Melbourne, Victoria, Australia
  • Belgium
      • Brussels, Belgium
      • Gent, Belgium
  • Canada
    • British Columbia
      • North Vancouver, British Columbia, Canada
    • Ontario
      • Ottawa, Ontario, Canada
      • Toronto, Ontario, Canada
    • Quebec
      • Montreal, Quebec, Canada
  • Chile
      • Santiago, Chile
      • Vina del Mar, Chile
  • Denmark
      • Aarhus, Denmark
      • Herlev, Denmark
      • Odense C, Denmark
  • France
      • Bordeaux, France
      • Lille, France
      • Marseille, France
      • Paris, France
      • Pierre Benite, France
      • Reims, France
      • Rennes, France
      • Toulouse, France
      • Villejuif, France
  • Germany
      • Buxtehude, Germany
      • Essen, Germany
      • Hannover, Germany
      • Kiel, Germany
      • Tuebingen, Germany
  • Ireland
      • Cork, Ireland
      • Dublin, Ireland
      • Galway, Ireland
  • Israel
      • Ramat Gan, Israel
  • Italy
      • Bergamo, Italy
      • Genova, Italy
      • Milano, Italy
      • Napoli, Italy
      • Padova, Italy
      • Siena, Italy
  • Japan
      • Asahikawa, Japan
      • Chuo, Japan
      • Fukuoka, Japan
      • Kagoshima, Japan
      • Kumamoto, Japan
      • Kurume, Japan
      • Kyoto, Japan
      • Matsumoto, Japan
      • Nagoya, Japan
      • Niigata, Japan
      • Okayama, Japan
      • Osaka, Japan
      • Sapporo, Japan
      • Sendai, Japan
      • Tokyo, Japan
      • Tsukuba, Japan
    • Sunto-gun
      • Susono, Sunto-gun, Japan
  • Korea, Republic of
      • Seoul, Korea, Republic of
  • Mexico
      • Chihuahua, Mexico
      • Distrito Federal, Mexico
      • Mexico City, Mexico
      • Monterrey, Mexico
  • Netherlands
      • Amsterdam, Netherlands
      • Nijmegen, Netherlands
  • New Zealand
      • Dunedin, New Zealand
      • Tauranga, New Zealand
  • Poland
      • Warszawa, Poland
  • Russian Federation
      • Istra, Russian Federation
      • Moscow, Russian Federation
      • Saint Petersburg, Russian Federation
  • South Africa
      • Kraaifontein, South Africa
    • Gauteng
      • Johannesburg, Gauteng, South Africa
      • Sandton, Gauteng, South Africa
    • Pretoria
      • Groenkloof, Pretoria, South Africa
    • Western Cape
      • Cape Town, Western Cape, South Africa
  • Spain
      • A Coruna, Spain
      • Barcelona, Spain
      • Madrid, Spain
      • Pamplona, Spain
      • San Sebastian, Spain
      • Sevilla, Spain
      • Valencia, Spain
    • Guipuzcoa
      • Donostia-San Sebastian, Guipuzcoa, Spain
  • Sweden
      • Göteborg, Sweden
      • Lund, Sweden
      • Stockholm, Sweden
      • Uppsala, Sweden
  • Switzerland
      • Geneve, Switzerland
      • Lausanne, Switzerland
    • ZH
      • Zürich, ZH, Switzerland
  • United Kingdom
      • Edinburgh, United Kingdom
      • London, United Kingdom
      • Manchester, United Kingdom
  • United States
    • Alabama
      • Birmingham, Alabama, United States
    • Arizona
      • Scottsdale, Arizona, United States
    • Arkansas
      • Little Rock, Arkansas, United States
    • California
      • Los Angeles, California, United States
      • San Francisco, California, United States
      • Santa Barbara, California, United States
      • Santa Monica, California, United States
    • Colorado
      • Aurora, Colorado, United States
      • Denver, Colorado, United States
    • District of Columbia
      • Washington, District of Columbia, United States
    • Florida
      • Fort Lauderdale, Florida, United States
      • Jacksonville, Florida, United States
      • Ocala, Florida, United States
      • West Palm Beach, Florida, United States
    • Illinois
      • Chicago, Illinois, United States
      • Peoria, Illinois, United States
    • Iowa
      • Iowa City, Iowa, United States
    • Kansas
      • Kansas City, Kansas, United States
    • Maryland
      • Lutherville, Maryland, United States
    • Massachusetts
      • Boston, Massachusetts, United States
    • Michigan
      • Ann Arbor, Michigan, United States
    • Minnesota
      • Fridley, Minnesota, United States
    • Montana
      • Billings, Montana, United States
    • Nebraska
      • Omaha, Nebraska, United States
    • Nevada
      • Las Vegas, Nevada, United States
    • New York
      • Rochester, New York, United States
    • North Carolina
      • Charlotte, North Carolina, United States
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States
    • Tennessee
      • Nashville, Tennessee, United States
    • Texas
      • Austin, Texas, United States
      • Dallas, Texas, United States
    • Utah
      • Salt Lake City, Utah, United States
    • Virginia
      • Fairfax, Virginia, United States
    • Washington
      • Spokane, Washington, United States

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Have histologically or cytologically confirmed melanoma
  • Have unresectable Stage III or Stage IV melanoma, as per AJCC staging system not amenable to local therapy
  • A minimum of 1 measurable lesion by CT or MRI
  • Provide a baseline tumor biopsy
  • Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1

Exclusion Criteria:

  • Has received prior systemic treatment for unresectable or metastatic melanoma (except BRAF directed therapy)
  • Has received prior therapy with an anti-PD-1, anti-PD-L1, anti-PD-L2, anti-CD137, or IDO1 inhibitor or any other antibody or drug specifically targeting checkpoint pathways other than anti-CTLA-4 which is permitted in the adjuvant setting
  • Has received prior adjuvant therapy, monoclonal antibody or an investigational agent or device within 4 weeks or 5 half-lives (whichever is longer)
  • Has an active infection requiring systemic therapy
  • Has known history of human immunodeficiency virus (HIV) (HIV 1/2 antibodies)
  • Has known history of or is positive for Hepatitis B or Hepatitis C
  • Is pregnant or breastfeeding or expecting to conceive or father children within the projected duration of the study, starting with the screening visit through 120 days after the last dose of study treatment

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Pembrolizumab + Epacadostat
Drug: pembrolizumab + epacadostat
  • Pembrolizumab will be administered intravenously every 3 weeks starting at Day 1 (Week 1)
  • Epacadostat will be administered orally daily starting at Day 1 (Week 1)
Active Comparator: Pembrolizumab + Placebo
Drug: pembrolizumab + placebo
  • Pembrolizumab will be administered intravenously every 3 weeks starting at Day 1 (Week 1)
  • Placebo will be administered orally daily starting at Day 1 (Week 1)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Progression-free Survival
Time Frame: Assessed every 9 weeks for duration of study participation which is estimated to be 24 months
Progression-free survival, defined as the time from date of randomization until the earliest date of disease progression, as determined by independent central review of objective radiographic disease assessments per RECIST 1.1, or death from any cause, whichever comes first.
Assessed every 9 weeks for duration of study participation which is estimated to be 24 months
Overall Survival (OS) Rate at 6 Months
Time Frame: Assessed every 9 weeks of study participation which is estimated to be 24 months. The OS rate at Month 6 was calculated.
Defined as time from date of randomization to date of death due to any cause. OS was calculated using product-limit (Kaplan-Meier) method for censored data.
Assessed every 9 weeks of study participation which is estimated to be 24 months. The OS rate at Month 6 was calculated.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Objective Response Rate (ORR)
Time Frame: Assessed every 9 weeks for duration of study participation which is estimated to be 24 months
Objective response rate (ORR) is defined as the percentage of the participants in the analysis population who have a confirmed complete response (CR) or partial response (PR) based on RECIST 1.1 by independent central review.
Assessed every 9 weeks for duration of study participation which is estimated to be 24 months
Safety and Tolerability, as Assessed by Percentage of Participants With Adverse Events
Time Frame: Through up to 90 days after end of treatment, up to 27 months
Safety and tolerability, as assessed by percentage of participants with adverse events and changes in laboratory parameters.
Through up to 90 days after end of treatment, up to 27 months
Duration of Response (DOR)
Time Frame: Assessed every 9 weeks for duration of study participation which is estimated to be 24 months
Defined as the time from the earliest date of qualifying response until earliest date of disease progression, per RECIST v1.1, or death from any cause, whichever comes first. Includes participants with complete response or partial response.
Assessed every 9 weeks for duration of study participation which is estimated to be 24 months
Apparent Oral Clearance (CL/F) of Epacadostat
Time Frame: Through up to 30 days after the end of treatment, up to 25 months
Defined as oral dose clearance.
Through up to 30 days after the end of treatment, up to 25 months
Apparent Volume of Distribution (Vd/F) of Epacadostat
Time Frame: Through up to 30 days after the end of treatment, up to 25 months
Apparent volume of distribution after administration.
Through up to 30 days after the end of treatment, up to 25 months
Clearance (CL) of Pembrolizumab
Time Frame: Through up to 30 days after the end of treatment, up to 25 months
Through up to 30 days after the end of treatment, up to 25 months
Volume of Distribution (V) of Pembrolizumab
Time Frame: Through up to 30 days after the end of treatment, up to 25 months
Through up to 30 days after the end of treatment, up to 25 months
Formation of Anti-pembrolizumab Antibodies
Time Frame: Through up to 30 days after the end of treatment, up to 25 months
Evaluate the measurement of anti-drug antibodies (ADA).
Through up to 30 days after the end of treatment, up to 25 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Incyte Corporation

Collaborators

Merck Sharp & Dohme LLC

Investigators

  • Study Director: Mark Jones, MD, Incyte Corporation

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 21, 2016

Primary Completion (Actual)

January 8, 2018

Study Completion (Actual)

August 16, 2019

Study Registration Dates

First Submitted

April 22, 2016

First Submitted That Met QC Criteria

April 22, 2016

First Posted (Estimated)

April 26, 2016

Study Record Updates

Last Update Posted (Actual)

August 24, 2025

Last Update Submitted That Met QC Criteria

August 21, 2025

Last Verified

August 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • INCB 24360-301 (ECHO-301)
  • 2015-004991-31 (EudraCT Number)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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