Efficacy and Safety Study of Navarixin (MK-7123) in Combination With Pembrolizumab (MK-3475) in Adults With Selected Advanced/Metastatic Solid Tumors (MK-7123-034)

Inclusion Criteria:

All Participants

- Has one of the following histologically- or cytologically-confirmed
advanced/metastatic solid tumors: NSCLC, CRPC, or MSS CRC, by pathology report and has
received, or been intolerant to, or has been ineligible for all treatment known to
confer clinical benefit.

- Has Stage III or Stage IV disease that is not surgically resectable.

- Has measureable disease by RECIST 1.1 criteria as assessed by the local site
investigator/radiology.

- Has supplied tumor tissue from either a newly obtained biopsy or an archival specimen
for biomarker analysis.

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

- Male participants must agree to use contraception during the treatment period and for
at least 120 days after the last dose of study treatment and refrain from donating
sperm during this period.

- Female participants must agree to follow the contraceptive guidance during the
treatment period and for at least 120 days after the last dose of study treatment.

- Demonstrates adequate organ function.

Non-small Cell Lung Cancer (NSCLC) Participants

- Has histologically or cytologically confirmed diagnosis of Stage IV metastatic NSCLC.

- Has progressed on treatment with an anti-Programmed Death-Ligand 1 (PD-L1) monoclonal
antibody (mAb) administered either as monotherapy, or in combination with other
checkpoint inhibitors or other therapies. PD-L1 treatment progression is defined by
meeting all of the following criteria: a) Has received ≥2 doses of an approved
anti-PD-L1 mAb; b) Has demonstrated disease progression after anti-PD-L1 as defined by
RECIST 1.1; c) Progressive disease has been documented within 12 weeks from the last
dose of anti-PD-L1 mAb.

Castration Resistant Prostate Cancer (CRPC) Participants

- Has histologically- or cytologically-confirmed adenocarcinoma of the prostate.
Components of small cell prostate cancer are permitted.

- Has prostate cancer progression on the most recent treatment, as determined by the
investigator, by means of one of the following: a) Prostate-Specific Antigen (PSA)
progression using local laboratory values as defined by a minimum of 2 rising PSA
levels with an interval of ≥1 week between each assessment where the PSA value at
screening should be ≥2 ng/mL; b) Radiographic disease progression in soft tissue based
on RECIST 1.1 criteria with or without PSA progression; c) Radiographic disease
progression in bone defined as the appearance of 2 or more new bone lesions on bone
scan with or without PSA progression.

- Has progressed on at least one second generation anti-androgen therapy (e.g.,
enzalutamide, abiraterone).

- Has ongoing androgen deprivation with serum testosterone <50 ng/dL (<2.0 nM).

Microsatellite Stable Colorectal Cancer (MSS-CRC) Participants

- Has a histologically proven locally advanced unresectable or metastatic (Stage IV)
CRC.

- Has locally confirmed (MSS) CRC; participants with microsatellite instability-high
(MSI-H) or microsatellite unstable CRC are not eligible.

- Has been previously treated with standard therapies, which must include
fluoropyrimidine, oxaliplatin, and irinotecan.

Exclusion Criteria:

- Has a known additional malignancy that is progressing or has required active treatment
within the past 2 years. Note: Participants with basal cell carcinoma of the skin,
squamous cell carcinoma of the skin, or carcinoma in situ (e.g. breast carcinoma,
cervical cancer in situ) that have undergone potentially curative therapy are not
excluded.

- Has known active central nervous system (CNS) metastases and/or carcinomatous
meningitis. Participants with previously treated brain metastases may participate
provided they are radiologically stable, i.e., without evidence of progression for at
least 4 weeks by repeat imaging, clinically stable and without requirement of steroid
treatment for at least 14 days prior to first dose of study treatment.

- Has had a severe hypersensitivity reaction to treatment with any mAb or components of
the study treatment(s).

- Has an active autoimmune disease that has required systemic treatment in the past 2
years except vitiligo or resolved childhood asthma/atopy. Participants who have
previously been permanently discontinued from PD-(L)1 therapy due to immune related
side effects are not eligible for this study.

- Has an active infection requiring systemic therapy.

- Has symptomatic ascites or pleural effusion.

- Has interstitial lung disease that required oral or intravenous glucocorticoids to
assist with management.

- Has a history of (non-infectious) pneumonitis that required steroids or has current
pneumonitis.

- Has undergone prior allogeneic hematopoietic stem cell transplantation within the last
5 years. Note: Participants who have had a stem cell transplant >5 years ago are
eligible as long as there are no symptoms of graft-versus-host disease (GVHD).

- Has a known history of human immunodeficiency virus (HIV) infection.

- Has a known history of Hepatitis B or known active Hepatitis C virus infection.

- Has a history or current evidence of a gastrointestinal condition (e.g. inflammatory
bowel disease, Crohn's disease, ulcerative colitis) or impaired liver function or
diseases that in the opinion of the Investigator may significantly alter the
absorption or metabolism of oral medications; any condition, therapy, or laboratory
abnormality that might confound the results of the study, interfere with the
participant's participation for the full duration of the study, make administration of
the study drugs hazardous, or make it difficult to monitor AEs such that it is not in
the best interest of the participant to participate, in the opinion of the treating
Investigator.

- Is pregnant or expecting to conceive or father children within the projected duration
of the study.

- Has undergone major surgery and has not recovered adequately from any toxicity and/or
complications from the intervention prior to starting study treatment.

- Has CRPC or MSS CRC and has received prior therapy with an anti-PD-1, anti-PD-L1, or
anti-PD-L2 agent.

- Has been treated with an agent directed to another stimulatory or co-inhibitory Tcell
receptor (e.g. cytotoxic T-lymphocyte protein 4 [CTLA-4], tumor necrosis factor
receptor superfamily, member 4 [OX 40], tumor necrosis factor receptor superfamily
member 9 [CD137]).

- Has received prior systemic anti-cancer therapy including investigational agents or
has used an investigational device within 28 days prior to the first dose of study
treatment.

- Has received prior radiotherapy (not to target lesions) within 2 weeks of start of
study treatment.

- Is expected to require any other form of antineoplastic therapy while on study.

- Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy
in excess of replacement doses (prednisone ≤10 mg/day is acceptable), or on any other
form of immunosuppressive medication.

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

- Has been previously treated with a chemokine receptor 2 (CXCR2) inhibitor (e.g.
AZD5069, reparixin, danirixin, LY3041658 Ab, HuMax-IL8, etc.).