Study of MK-5890 as Monotherapy and in Combination With Pembrolizumab (MK-3475) in Adults With Advanced Solid Tumors (MK-5890-001)

Inclusion Criteria:

Arms 1 & 2: Histologically or cytologically confirmed advanced/metastatic solid tumor by pathology report and has received or been intolerant to all treatment known to confer clinical benefit
Arm 3: Histologically or cytologically confirmed diagnosis of stage IV (M1a or M1b per current American Joint Committee on Cancer criteria) non-squamous NSCLC
Arm 4: Triple-negative breast cancer (TNBC) that is locally recurrent, inoperable, not previously treated with chemotherapy, and which cannot be treated with curative intent OR metastatic disease not previously treated with chemotherapy
Measurable disease by RECIST 1.1. as assessed by the local site investigator/radiologist. Target lesions situated in a previously irradiated area are considered measurable if progression has been demonstrated in such lesions
Adequate organ function
Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
Male participants must agree to use adequate contraception during the treatment period and for at least 120 days after the last dose of MK-5890 or pembrolizumab OR 180 days after the last dose of chemotherapeutic agents and refrain from donating sperm during this period
Female participants must not be pregnant or breastfeeding and agree to follow use adequate contraception during the treatment period and for at least 120 days after the last dose of MK-5890 or pembrolizumab OR 180 days after the last dose of chemotherapeutic agents
Submit an evaluable baseline tumor sample for analysis (either a newly obtained or archival tumor sample)

Exclusion Criteria:

History of a second malignancy, unless potentially curative treatment has been completed with no evidence of malignancy for 2 years
Clinically active central nervous system metastases and/or carcinomatous meningitis
Has had a severe hypersensitivity reaction to treatment with a monoclonal antibody (mAb) and/or other components of the study treatment
Active infection requiring systemic treatment
History of interstitial lung disease
History of (noninfectious) pneumonitis that required steroids or current pneumonitis
Symptomatic ascites or pleural effusion
Previously had a stem cell or bone marrow transplant
Previously had a solid organ transplant
Active autoimmune disease that has required systemic treatment in the past 2 years (i.e., with use of disease-modifying agents, corticosteroids, or immunosuppressive drugs) except vitiligo or resolved childhood asthma/atopy
Known human immunodeficiency virus (HIV) and/or active and acute Hepatitis B or C infections
Not fully recovered from any effects of major surgery without significant detectable infection
Pregnant or breastfeeding, or expecting to conceive or father children within the projected duration of the study
Had chemotherapy, definitive radiation, or biological cancer therapy within 4 weeks (2 weeks for palliative radiation) before the first dose of study treatment, or has not recovered to Grade ≤1 or better from any AEs that were due to cancer therapeutics administered more than 4 weeks earlier
Expected to require any other form of antineoplastic therapy while participating in this study
On chronic systemic steroid therapy in excess of replacement doses (e.g., exceeding 10 mg/day of prednisone equivalent), or on any other form of immunosuppressive medication
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 (including alcohol), as determined by the treating investigator. Participants who use cannabis for medicinal purposes or to treat specific symptoms will not be excluded unless it is being abused in the opinion of the treating investigator
Received a live-virus vaccine within 28 days before the first dose of study treatment
Currently participating and receiving study treatment in a study of an investigational agent or has participated and received study treatment in a study of an investigational agent or has used an investigational device within 28 days before the first dose of study treatment

Additional Exclusion Criteria for Participants in Arm 3:

Has received radiation therapy to the lung that is >30 Gray (Gy) within 6 months before the first dose of study treatment
Is unable to interrupt aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs), other than an aspirin dose ≤1.3 g per day, for a 5-day period (8-day period for long-acting agents, such as piroxicam).
Is unable or unwilling to take folic acid or vitamin B12 supplementation

Additional Exclusion Criteria for Participants in Arm 4:

Has a known history of hypersensitivity or allergy to nab-paclitaxel or any of its components
Has neuropathy ≥Grade 2
Has a history of class II-IV congestive heart failure or myocardial infarction within 6 months of randomization
Has received previous treatment with immune checkpoint inhibitor(s) (eg, Programmed Cell Death Receptor 1 (PD-1)/PD-L1)