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

Prior treatment

• Prior autologous/allogeneic stem cell or tissue/solid organ transplant
• Prior treatment with MGD009, enoblituzumab, or other B7-H3 targeted agents for cancer.
• 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.

Other illness

• 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.
• Clinically significant cardiovascular disease, lung compromise, venous insufficiency, or gastrointestinal disorders.
• History of Guillain-Barre syndrome, myasthenia gravis, or other autoimmune sensory or motor neuropathies.

Lab values

• 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.

Other

• Participants with greater than Grade 1 peripheral neuropathy.
• Pleural effusion or ascites. Trace pleural or peritoneal fluid is not exclusionary.

• 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.