A Study of MK-1088 as Monotherapy and in Combination With Pembrolizumab in Participants With Advanced Solid Tumors (MK-1088-002)

A Phase 1/Phase 2 Study to Evaluate the Safety and Tolerability of MK-1088 as Monotherapy and in Combination With Pembrolizumab in Participants With Advanced Solid Tumors

The study will evaluate the safety, tolerability, and pharmacokinetics (PK) of MK-1088 in monotherapy and in combination with pembrolizumab in participants with advanced solid tumors who have not responded to conventional therapy. The effect of MK-1088 on tumor size will also be examined.

The main inclusion and exclusion criteria include but are not limited to the following:

Inclusion Criteria:

• Has a histologically- or cytologically-confirmed diagnosis of advanced/metastatic solid tumor by pathology report and have received, have been intolerant to, or have been ineligible for treatment known to confer clinical benefit
• For metastatic castrate-resistant prostate cancer (mCRPC) only: (1) Must have previously received docetaxel, prior treatment with one other chemotherapy is allowed as well as up to 2 second-generation hormonal manipulations and (2) have prostate cancer progression within 6 months before screening, as determined by the investigator
• If human immunodeficiency virus (HIV) positive, has well-controlled HIV on anti-retroviral therapy (ART)

Exclusion Criteria:

• Has had chemotherapy, definitive radiation, or biological cancer therapy within 4 weeks (2 weeks for palliative radiation) before the first dose of study intervention
• Has a history of a second malignancy, unless potentially curative treatment has been completed with no evidence of malignancy for 2 years
• Has clinically active central nervous system (CNS) metastases and/or carcinomatous meningitis
• Has an active infection requiring therapy
• Has a history of interstitial lung disease
• Has a history of (noninfectious) pneumonitis that required steroids or current pneumonitis
• Has an active autoimmune disease that has required systemic treatment in the past 2 years
• Has concurrent active Hepatitis B and Hepatitis C virus infection
• Has HIV with a history of Kaposi's sarcoma and/or Multicentric Castleman's Disease
• Has not fully recovered from any effects of major surgery without significant detectable infection
• Has a history or current evidence of a gastrointestinal (GI) condition or impaired liver function or diseases that in the opinion of the investigator may significantly alter the absorption or metabolism of oral medications
• Has clinically significant cardiovascular disease within 12 months from first dose of study intervention, including New York Health Association (NYHA) Class III or IV congestive heart failure, unstable angina, myocardial infarction, cerebral vascular accident, or cardiac arrhythmia associated with hemodynamic instability
• Has a corrected QT interval using Fridericia's Correction Formula (QTcF) >470 msec
• Has history of an allogeneic stem cell transplant or a solid organ transplant.
• Has received prior systemic anticancer therapy including investigational agents within 4 weeks before allocation
• Has received prior radiotherapy within 2 weeks of start of study intervention, or had radiation-related toxicities requiring corticosteroids
• Has received a live or live-attenuated vaccine within 30 days before the first dose of study intervention
• Has a "superscan" bone scan