Pembrolizumab Plus Epacadostat vs Pembrolizumab Plus Placebo in Metastatic Non-Small Cell Lung Cancer (KEYNOTE-654-04/ECHO-305-04)

Inclusion Criteria:

- Histologically or cytologically confirmed diagnosis of stage IV NSCLC without
epidermal growth factor receptor (EGFR)-sensitizing mutation, ROS1 and/or anaplastic
lymphoma kinase (ALK) translocation.

- Measurable disease based on RECIST 1.1.

- Tumor tissue that demonstrates programmed cell death ligand 1 (PD-L1) expression in ≥
50% of tumor cells (tumor proportion score [TPS] ≥ 50%) as assessed by
immunohistochemistry at a central laboratory.

- Life expectancy of at least 3 months.

- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.

- Adequate organ function per protocol-defined criteria.

Exclusion Criteria:

- Known untreated central nervous system metastases and/or carcinomatous meningitis.

- History of (noninfectious) pneumonitis that required systemic steroids or current
pneumonitis/interstitial lung disease.

- Symptomatic ascites or pleural effusion.

- Known history of an additional malignancy, except if the participant has undergone
potentially curative therapy with no evidence of that disease recurrence for 5 years
since initiation of that therapy.

- Active autoimmune disease that has required systemic treatment in past 2 years.

- Has had an allogeneic tissue/solid organ transplant.

- Has a known history of human immunodeficiency virus (HIV) infection. HIV testing is
not required unless mandated by the local health authority.

- Has known history of or is positive for active Hepatitis B (HBsAg reactive) or has
active Hepatitis C (HCV RNA). Note: Testing must be performed to determine
eligibility.

- History or presence of an abnormal electrocardiogram (ECG) that, in the Investigator's
opinion, is clinically meaningful.

- Use of protocol-defined prior/concomitant therapy.