Key Inclusion Criteria:

          -  Histologically or cytologically confirmed, locally advanced or metastatic solid
             malignancy and has exhausted all available standard therapy or is not a candidate for
             the available standard therapy.

          -  Eastern Cooperative Oncology Group (ECOG) performance status 0-1.

          -  During dose escalation - Subjects who received prior therapy with anti-PD-1,
             anti-PD-L1, anti- CTLA-4, OX-40, CD137, etc., are eligible.

        During cohort expansion: All subjects must have measurable disease as defined by RECIST
        v1.1.

        Expansion Cohorts:

          -  Cohort 1 (subjects with advanced epithelial ovarian, fallopian tube, or primary
             peritoneal carcinoma)

          -  Subject must have platinum refractory/resistant ovarian cancer defined as
             refractoriness to platinum-containing regimen or disease recurrence < 6 months after
             completion of a platinum-containing regimen

          -  Cohort 2 (endometrial cancer cohort)

          -  Subjects with locally advanced or metastatic microsatellite stable endometrial cancer
             with disease recurrence or progression during or after prior therapy that included
             platinum-based chemotherapy.

          -  Subjects must have documented MSS status by an approved test e.g. genomic testing, IHC
             for mismatch repair proficient.

          -  Subjects must have received no more than 2 prior systemic cytotoxic therapies; there
             are no limits to the number of prior endocrine or antiangiogenic regimens

          -  Cohort 3 (basket cohort, excludes tumor types in cohorts 1 and 2)

          -  Tumor types with high expression of PVRL2 (determined by central testing).

        Key Exclusion Criteria:

          -  Active autoimmune disease requiring systemic therapy in the last 2 years prior to the
             first dose of COM701.

          -  Symptomatic interstitial lung disease or inflammatory pneumonitis.

          -  History of immune-related events that lead to immunotherapy treatment discontinuation.

          -  Untreated or symptomatic central nervous system (CNS) metastases.

        Key Exclusion Criteria For Dose Expansion Cohorts:

          -  Cohort 1: Prior therapy with an anti-PD-1/PD-L1/2, COM701 (or any inhibitor of PVRIG),
             anti-TIGIT antibody, anti-CTLA-4 antibody, anti-OX-40 antibody, anti-CD137 antibody.

          -  Cohort 2: Prior therapy with COM701 (or any inhibitor of PVRIG) or anti-TIGIT
             antibody. Subjects with MSI-H endometrial cancer are ineligible.

          -  Cohort 3: Prior therapy with COM701 (or any inhibitor of PVRIG) or anti-TIGIT antibody
             are ineligible.