Study to Evaluate IMGS-001 Treatment in Patients With Relapsed or Refractory Advanced Solid Tumors

Part 1 is a Phase 1a, first-in-human, open-label dose-escalation study to determine the safety, tolerability, and maximum tolerated dose (MTD) of IMGS-001. The safety, tolerability, PK parameters, and preliminary antitumor activity of IMGS-001 will be assessed in adult patients with advanced solid tumors refractory to appropriate standard of care (SOC) treatments. Based on the MTD and other information (e.g., tolerability, PK, PD, target engagement), multiple doses of IMGS-001 will be selected for further evaluation. Additional subjects may be backfilled across Phase 1a doses (or other intermediate doses at or below the MAD/MTD) to assure adequate clinical data to support dose optimization and selection of appropriate doses for use in the Phase 1b. Approximately 35 total subjects will be enrolled in Phase 1a. Part 2 is a Phase 1b, open-label, dose-expansion study of five prespecified tumor cohorts to assess preliminary antitumor activity of IMGS-001 in patients that are refractory or intolerant to other appropriate prior standard therapies. Stage 1 will consist of two separate cohort designs: 4 single-dose cohorts and 1 tumor specific dose optimization cohort in NSCLC. The 4 single dose Stage 1 cohorts will initially enroll approximately 10 subjects in each of the following cohorts treated with IMGS-001: * Cohort 1: Ovarian cancer (high-grade epithelial, fallopian tube, or primary peritoneal; PD-L1 positive \[CPS ≥1\]) * Cohort 2: 9p24.1 lymphomas (classic Hodgkin's, PMBCL) * Cohort 3: Nasopharyngeal cancer (non-keratinizing) * Cohort 4: Head and neck squamous cell carcinoma (HPV+, PD-L1 positive \[CPS ≥1\]) Each cohort will be assessed to meet efficacy criteria to continue into a randomized dose-optimization. Within each cohort that meets prespecified efficacy criteria, the expanded cohorts will have randomly assigned (1:1) subjects to receive one of two doses used in the Phase 1a. Within each Arm, 20 eligible subjects will be treated with the assigned dose of IMGS-001. For the Stage 1 dose optimization in the NSCLC cohort, approximately 20 subjects will initially be randomized 1:1 to one of two dose arms. If efficacy criteria are met, the cohort may be expanded to randomize approximately 20 additional subjects across these two doses.