Further development of this compound with ipilimumab in the treatment of melanoma is no longer being pursued.

The study design included an open-label, dose escalation phase followed by a blinded, randomized phase, which combined epacadostat (an oral IDO1 inhibitor) with an approved therapy and compared to approved therapy plus placebo in metastatic melanoma patients.

Only Phase 1 of the study, dose escalation phase, was conducted. The study was terminated due to a business decision.

Inclusion Criteria:

• Male or female subjects, aged 18 years or older with unresectable or metastatic melanoma.
• A life expectancy of >12 weeks.
• Laboratory ranges and medical criteria met, as defined within the protocol.
• Subject may have received more than 1 prior regimen of systematic treatment for unresectable or metastatic melanoma.
• For Phase 2 period of the study only, Subjects must have archival tumor tissue available and collected with the prior 6 months or accessible disease for pre-treatment, study biopsy.

Exclusion Criteria:

• Pregnant or nursing women.
• Current investigational trial participation with another investigational product or subjects who have received any anticancer medications within 21 days prior to screening (6 weeks for mitomycin-C or nitrosoureas.)
• Subjects receiving monoamine oxidase inhibitors (MAOI)s; subjects who have ever had Serotonin Syndrome after receiving one or more serotonergic drugs.
• Subjects who have received prior immune checkpoint inhibitors (eg anti-CTLA-4, anti-programmed death 1 (PD-1), anti-programmed death-ligand 1 (PD-L1) and others) who have had Grade 3 or 4 hepatotoxicity, immune colitis requiring infliximab, endocrine toxicity not controlled by replacement, any other Grade 4 immune adverse events (AEs) or ocular toxicity
• Subjects with protocol-specified active autoimmune process except vitiligo or thyroiditis.
• Subjects with concurrent conditions that would jeopardize the safety of the safety of the subject or compliance with the protocol.