This was an open-label, nonrandomized, Phase 1/2 study designed to determine the safety, tolerability, and efficacy of epacadostat when given in combination with pembrolizumab and 7 different chemotherapy regimens described as Treatment Groups A through G below (see Study Drug and Background Therapies, Dose, and Mode of Administration). Phase 1 consisted of a 3 + 3 + 3 design intended to determine the MTD or PAD of epacadostat when given in combination with pembrolizumab and chemotherapy; efficacy was also explored.

Phase 2 was designed to enroll efficacy expansion cohorts to further evaluate the safety, tolerability, and efficacy of epacadostat at the MTD or PAD (as selected in Phase 1) when given in combination with pembrolizumab and chemotherapy. Each efficacy expansion cohort was to enroll participants with 1 specific type of advanced or metastatic solid tumor. Additional cohorts (ie, the mandatory biopsy cohorts) were designed to evaluate changes in the tumor microenvironment in participants with any advanced or metastatic solid tumor who had progressed on previous therapy with a PD-1 or a PD-L1 inhibitor.

No participants were enrolled in any Phase 2 efficacy expansion cohort, or in any Phase 2 mandatory biopsy cohort receiving Treatment A, B, F, or G. Phase 2 mandatory biopsy cohort participants received Treatments C, D, or E (ie, were included in Treatment Groups C, D, or E). Participants were assigned to a treatment group based on the chemotherapy regimen most appropriate for their tumor type.

Inclusion Criteria:

• Histologically or cytologically confirmed diagnosis of selected advanced or metastatic solid tumors.
• Presence of measurable disease per RECIST v1.1.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.

Exclusion Criteria:

• Laboratory and medical history parameters not within the Protocol-defined range.
• Receipt of anticancer medications or investigational drugs within the Protocol-defined intervals before the first administration of study drug.
• Previous radiotherapy within 2 weeks of starting study therapy.
• Known active central nervous system (CNS) metastases and/or carcinomatous meningitis.
• Has not recovered to ≤ Grade 1 from toxic effects of previous therapy and/or complications from previous surgical intervention before starting study therapy.
• Receipt of a live vaccine within 30 days of planned start of study therapy.
• Active infection requiring systemic therapy.
• Subjects who have any active or inactive autoimmune disease or syndrome.
• Women who are pregnant or breastfeeding.

Incyte shares data with qualified external researchers after a research proposal is submitted. These requests are reviewed and approved by a review panel on the basis of scientific merit. All data provided is anonymized to respect the privacy of patients who have participated in the trial in line with applicable laws and regulations.

The trial data availability is according to the criteria and process described on https://www.incyte.com/our-company/compliance-and-transparency

Data will be shared after the primary publication or 2 years after the study has ended for market authorized products and indications.

Data from eligible studies will be shared with qualified researchers according to the criteria and process described in the Data Sharing section of the www.incyteclinicaltrials.com website. For approved requests, the researchers will be granted access to anonymized data under the terms of a data sharing agreement