Epacadostat plus pembrolizumab versus placebo plus pembrolizumab in patients with unresectable or metastatic melanoma (ECHO-301/KEYNOTE-252): a phase 3, randomised, double-blind study.

Abstract

BACKGROUND:

Immunotherapy combination treatments can improve patient outcomes. Epacadostat, an IDO1 selective inhibitor, and pembrolizumab, a PD-1 inhibitor, showed promising antitumour activity in the phase 1-2 ECHO-202/KEYNOTE-037 study in advanced melanoma. In this trial, we aimed to compare progression-free survival and overall survival in patients with unresectable stage III or IV melanoma receiving epacadostat plus pembrolizumab versus placebo plus pembrolizumab.

METHODS:

In this international, randomised, placebo-controlled, double-blind, parallel-group, phase 3 trial, eligible participants were aged 18 years or older, with unresectable stage III or IV melanoma previously untreated with PD-1 or PD-L1 checkpoint inhibitors, an ECOG performance status of 0 or 1, and had a known BRAFV600 mutant status or consented to BRAFV600 mutation testing during screening. Patients were stratified by PD-L1 expression and BRAFV600 mutation status and randomly assigned (1:1) through a central interactive voice and integrated web response system to receive epacadostat 100 mg orally twice daily plus pembrolizumab 200 mg intravenously every 3 weeks or placebo plus pembrolizumab for up to 2 years. We used block randomisation with a block size of four in each stratum. Primary endpoints were progression-free survival and overall survival in the intention-to-treat population. The safety analysis population included randomly assigned patients who received at least one dose of study treatment. The study was stopped after the second interim analysis; follow-up for safety is ongoing. This study is registered with ClinicalTrials.gov, number NCT02752074.

FINDINGS:

Between June 21, 2016, and Aug 7, 2017, 928 patients were screened and 706 patients were randomly assigned to receive epacadostat plus pembrolizumab (n=354) or placebo plus pembrolizumab (n=352). Median follow-up was 12·4 months (IQR 10·3-14·5). No significant differences were found between the treatment groups for progression-free survival (median 4·7 months, 95% CI 2·9-6·8, for epacadostat plus pembrolizumab vs 4·9 months, 2·9-6·8, for placebo plus pembrolizumab; hazard ratio [HR] 1·00, 95% CI 0·83-1·21; one-sided p=0·52) or overall survival (median not reached in either group; epacadostat plus pembrolizumab vs placebo plus pembrolizumab: HR 1·13, 0·86-1·49; one-sided p=0·81). The most common grade 3 or worse treatment-related adverse event was lipase increase, which occurred in 14 (4%) of 353 patients receiving epacadostat plus pembrolizumab and 11 (3%) of 352 patients receiving placebo plus pembrolizumab. Treatment-related serious adverse events were reported in 37 (10%) of 353 patients receiving epacadostat plus pembrolizumab and 32 (9%) of 352 patients receiving placebo plus pembrolizumab. There were no treatment-related deaths in either treatment group.

INTERPRETATION:

Epacadostat 100 mg twice daily plus pembrolizumab did not improve progression-free survival or overall survival compared with placebo plus pembrolizumab in patients with unresectable or metastatic melanoma. The usefulness of IDO1 inhibition as a strategy to enhance anti-PD-1 therapy activity in cancer remains uncertain.

FUNDING:

Incyte Corporation, in collaboration with Merck Sharp & Dohme.

• Authors: Georgina V Long, Reinhard Dummer, Omid Hamid, Thomas F Gajewski, Christian Caglevic, Stephane Dalle, Ana Arance, Matteo S Carlino, Jean-Jacques Grob, Tae Min Kim, Lev Demidov, Caroline Robert, James Larkin, James R Anderson, Janet Maleski, Mark Jones, Scott J Diede, Tara C Mitchell
• Journal: The Lancet. Oncology (Lancet Oncol) Vol. 20 Issue 8 Pg. 1083-1097 (08 2019) ISSN: 1474-5488 [Electronic] England
• PMID: 31221619 (Publication Type: Clinical Trial, Phase III, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2019 Elsevier Ltd. All rights reserved.

Chemical References

• Antibodies, Monoclonal, Humanized
• Oximes
• Sulfonamides
• epacadostat
• pembrolizumab

Topics

• Adult
• Aged
• Antibodies, Monoclonal, Humanized (administration & dosage)
• Antineoplastic Combined Chemotherapy Protocols (therapeutic use)
• Double-Blind Method
• Female
• Humans
• Male
• Melanoma (drug therapy)
• Middle Aged
• Oximes (administration & dosage)
• Progression-Free Survival
• Sulfonamides (administration & dosage)