This is a multicenter, open-label study involving multiple specific advanced solid tumor types, consisting of a dose escalation Part A followed by an expansion Part B. Cancer subtypes will be studied in separate disease-specific cohorts in both Parts. Eight separate cohorts will enroll malignant melanoma, medullary thyroid cancer (MTC), glioblastoma, large cell neuroendocrine carcinoma (LCNEC), neuroendocrine prostate cancer (NEPC), high-grade gastroenteropancreatic (GEP), neuroendocrine carcinoma (NEC), other NEC, and solid tumors other than the above.