A Study of MGC018 in Combination With MGD019 in Participants With Advanced Solid Tumors

Inclusion Criteria:

* 1\. Ability to provide and document informed consent and willing and able to comply with all study procedures.
* Participants diagnosed with advanced solid tumors including but not limited to metastatic castration-resistant prostate cancer, melanoma, pancreatic cancer, hepatocellular carcinoma, ovarian cancer and renal cell carcinoma.
* Participants have received approved therapies according to their diagnosis.
* Participants must have an available tumor tissue sample. A fresh tumor biopsy may be performed if no archival sample is available.
* Eastern Cooperative Oncology Group performance status of less than or equal to 2.
* Life expectancy of at least 12 weeks.
* Evidence of measurable tumor for evaluation
* Acceptable end organ function according to laboratory results.
* Patients must agree to use highly-effective contraception during the study, and not donate sperm or ova.

Exclusion Criteria:

* Any underlying medical or psychiatric condition impairing participant's ability to receive, tolerate, or comply with the planned treatment or study procedures.
* Another malignancy that required treatment within the past 2 years. Participants who have had curative therapy for non-melanomatous skin cancer, localized prostate cancer (Gleason score \< 6), or carcinoma in situ are eligible for the study.
* Active viral, bacterial, or fungal infection requiring systemic treatment within 1 week of initiation of study drug. Participants are eligible after SARS CoV 2-related symptoms have fully recovered for ≥ 72 hours.
* History of immunodeficiency. Participants with HIV are eligible if they have a CD4+ count ≥ 300/µL, undetectable viral load, and maintained on antiretroviral therapy for a minimum of 4 weeks.
* Prior autologous/allogeneic stem cell or tissue/solid organ transplant
* Prior treatment with MGD009, enoblituzumab, or other B7-H3 targeted agents for cancer.
* Clinically significant cardiovascular disease, lung compromise, venous insufficiency, or gastrointestinal disorders.
* Participants with greater than Grade 1 peripheral neuropathy.
* Participants who have a history of severe adverse events (AEs) from immune checkpoint inhibitors (anti-PD-1, anti-PD-L1, or CTLA-4 inhibitors). All other AEs from prior immune checkpoint inhibitors must be resolved to Grade 1 or less. Participants with any grade neurologic toxicity from prior immune checkpoint inhibitors are excluded.
* Pleural effusion or ascites. Trace pleural or peritoneal fluid is not exclusionary.
* History of Guillain-Barre syndrome, myasthenia gravis, or other autoimmune sensory or motor neuropathies.