Study of Olaparib (MK-7339) in Combination With Pembrolizumab (MK-3475) in the Treatment of Homologous Recombination Repair Mutation (HRRm) and/or Homologous Recombination Deficiency (HRD)-Positive Advanced Cancer (MK-7339-007/KEYLYNK-007)

Inclusion Criteria: * Has a histologically- or cytologically-confirmed advanced (metastatic and/or unresectable) solid tumor (except breast or ovarian cancers whose tumor has a germline or somatic BRCA mutation) that is not eligible for curative treatment and for which standard of care therapy has failed. Participants must have progressed on or be intolerant to standard of care therapies that are known to provide clinical benefit. There is no limit on the number of prior treatment regimens. * Has either centrally-confirmed known or suspected deleterious mutations in ≥1 of the specified 15 genes involved in HRR or centrally-confirmed HRD based on the Lynparza HRR-HRD assay. * Has measurable disease per RECIST 1.1 as assessed by the local site investigator/radiology and confirmed in real time by blinded independent central review (BICR). BICR must confirm the presence of radiologically measurable disease per RECIST 1.1 for the participant to be eligible for the study. * Has a life expectancy of ≥3 months. * Must have had CR or PR while on the last treatment with prior cisplatin or carboplatin, or if received only oxaliplatin had CR, PR, or stable disease (SD) while on the last treatment with prior oxaliplatin (either as monotherapy or in combination) for advanced (metastatic and/or unresectable) solid tumor. Participant must also not have been refractory to prior platinum-containing therapy. * Has an Eastern Cooperative Oncology Group (ECOG) performance status of either 0 or 1…