Safety Study of MGD009 in B7-H3-expressing Tumors

This study is a Phase 1 open-label, dose escalation, cohort expansion, and efficacy follow-up study of MGD009 administered intravenously (IV) on an every-other-week schedule for up to one year (14 cycles). The dose escalation phase is designed to characterize the safety and tolerability of MGD009 and to define the maximum tolerated or maximum administered dose (MTD/MAD). This phase will enroll patients with mesothelioma, bladder cancer, melanoma, squamous cell carcinoma of the head and neck (SCCHN), non-small cell lung cancer (NSCLC), clear cell renal cell carcinoma (ccRCC), ovarian cancer, thyroid cancer, triple-negative breast cancer (TNBC), pancreatic cancer, colon cancer, soft tissue sarcoma, or prostate cancer. In the cohort expansion phase, 6 cohorts of 16 patients each will be enrolled to further evaluate the safety and potential efficacy of MGD009 administered at the MTD/MAD dose in patients with mesothelioma, bladder cancer, melanoma, SCCHN, NSCLC, or other specific tumors that express high levels of B7-H3. Pre- and on-study biopsies are required for melanoma patients in the cohort expansion phase. Two additional cohorts (up to15 patients each) will evaluate the use of prophylaxis therapies to mitigate toxicity. The survival follow-up phase consists of the 2-year period after the final dose of study drug. All tumor evaluations will be carried out by both Response Evaluation Criteria in Solid Tumors (RECIST) and immune-related response criteria (irRC).