A Phase 1/2a Study of 23ME-00610 in Patients With Advanced Solid Malignancies

This study includes a dose-escalation phase in Part A to determine the maximum tolerated dose (MTD) and/or recommended phase 2 dose (RP2D) followed by 6 monotherapy expansion arms in Part B to further evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and clinical activity of 23ME-00610 in patients with solid malignancies. 5 tumor- specific monotherapy expansion cohort will enroll up to 15 patients/cohort with the following locally advanced (unresectable) or metastatic solid malignancies: 1. Clear cell renal cell carcinoma (ccRCC) 2. Epithelial ovarian, fallopian tube or primary peritoneal carcinoma 3. Neuroendocrine cancers 4. Microsatellite instability-high (MSI-H) and/or tumor mutational burden-high (TMB-H) solid cancers and 5. Extensive stage Small cell lung cancer (ES-SCLC) A cohort of up to 8 evaluable adolescent patients with locally advanced (unresectable), or metastatic solid cancers will also be enrolled. Approximately 15 additional evaluable patients will be added to the cohorts with Epithelial ovarian, fallopian tube or primary peritoneal carcinoma and Neuroendocrine cancers in Part B to evaluate another dose level with pharmacologic or PD evidence of therapeutic effect below the MTD/RP2D identified in Part A (for a maximum of 30 patients in total at the alternate dose).