Study CP-MGC018-02 is a study of vobramitamab duocarmazine (MGC018) in combination with lorigerlimab (MGD019). The study is designed to characterize safety, tolerability, pharmacokinetics (PK), immunogenicity, pharmacodynamics, and preliminary antitumor activity. Participants with relapsed or refractory, unresectable, locally advanced or metastatic solid tumors including, but not limited to, metastatic castration-resistant prostate cancer (mCRPC), melanoma, pancreatic cancer, hepatocellular carcinoma (HCC), ovarian cancer, and renal cell carcinoma (RCC) will be enrolled.

Vobramitamab duocarmazine and lorigerlimab are administered separately on Day 1 of every 4-week (28-day) cycle at the assigned dose for each cohort. Participants who do not meet criteria for study drug discontinuation may receive study drugs for up to 2 years.

Tumor assessments are performed every 8 weeks (± 7 days) for the initial 6 months on study drugs, then every 12 weeks (± 21 days) until progressive disease (PD).

Participants will be followed for safety throughout the study. .

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.