Study of MK-7684 Alone and in Combination With Pembrolizumab in Advanced Solid Tumors (MK-7684-001)

Inclusion Criteria:

- For Part A Japanese cohort added with Amendment 7: Must reside in Japan and be of
Japanese descent and have adenocarcinoma of the stomach and/or gastric-esophageal
junction (GEJ) that is considered inoperable and that has received, and progressed on,
at least 1 prior chemotherapy regimen or human epidermal growth factor receptor 2
(HER2)/neu-targeted approved therapy (if HER2/neu-positive). In both cases,
participants must not have been treated with prior anti-PD-1/PD-L1 therapy

- For Part A participants with NSCLC added with Amendment 7: Must have a histologically
or cytologically confirmed diagnosis of stage IV (M1a or M1b per current AJCC
criteria, edition 8) non-squamous NSCLC

- For Parts A and B: Has histologically or cytologically confirmed metastatic solid
tumor

- Has measureable disease by Response Evaluation Criteria In Solid Tumors (RECIST)

- Has an Eastern Cooperative Oncology Group performance status of 0 to 1

- Females must not be pregnant

- Women of childbearing potential and male participants must agree to use adequate
contraception for the course of the study

- Has provided a tumor tissue sample (archival or newly obtained core or excisional
biopsy of a tumor lesion)

Exclusion Criteria:

- Has had chemotherapy, radiation, biological cancer therapy or major surgery within 4
weeks prior to the first dose of study treatment

- Has not recovered to Common Toxicity Criteria for Adverse Events Grade 1 or better
from the adverse events due to cancer therapeutics administered more than 4 weeks
prior to the first dose of study treatment

- Is currently participating in or has participated in a study of an investigational
agent or has used an investigational device within 4 weeks prior to the first dose of
study treatment

- Has received previous treatment with another agent targeting the T cell immunoglobulin
and immunoreceptor tyrosine-based inhibitory motif (TIGIT) receptor

- Has received previous treatment with an immunomodulatory agent (e.g., anti-programmed
cell death 1/ anti-programmed cell death ligand 1 or cytotoxic T-lymphocyte-associated
protein 4) and was discontinued from that treatment due to a Grade 3 or higher
immune-related adverse event

- Is expected to require any other form of antineoplastic therapy while participating in
the trial

- Is on chronic systemic steroid therapy in excess of replacement doses or on any other
form of immunosuppressive medication.

- Has a history of a previous additional malignancy unless potentially curative
treatment has been completed with no evidence of malignancy for 5 years

- Has known active central nervous system (CNS) metastases and/or carcinomatous
meningitis

- Has an active autoimmune disease

- Has an active infection requiring systemic treatment

- Has interstitial lung disease

- Has active or past history of (non-infectious) pneumonitis requiring steroids

- Has symptomatic ascites or pleural effusion

- Has previously had a hematopoetic stem cell transplant or solid organ transplant

- Is known to be human immunodeficiency virus (HIV) positive and/or known to have active
chronic or acute Hepatitis B or Hepatitis C

- Has a known psychiatric and/or substance abuse disorder that would make it difficult
for the participant to cooperate with the requirements of the trial

- Is a regular user (including recreational use) of any illicit drugs at the time of
signing informed consent, or has a recent history (within the last year) of substance
abuse

- Has received a live-virus vaccine within 30 days prior to the first dose of study
treatment

- Has had hormonal cancer therapy (e.g., tamoxifen, leuprolide). within 4 weeks prior to
the first dose of study treatment

- For Part A participants with NSCLC added with Amendment 7: Is unable to interrupt
aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) other than an aspirin
dose ≤1.3 gram per day for a 5-day period (8-day period for long-acting agents, such
as piroxicam)

- For Part A participants with NSCLC added with Amendment 7: Is unable or unwilling to
take folic acid or Vitamin B12 supplementation