This is a Phase 1a/1b, first-in-human (FIH), open-label, multi-center dose escalation and expansion study of the safety, pharmacokinetics (PK), pharmacodynamics, and antitumor activity of single-agent CT-95 in subjects with advanced (recurrent, unresectable, or metastatic) cancers associated with MSLN expression.

Phase 1a Dose Escalation: Participants with ovarian epithelial tumors, primary peritoneal or fallopian tube cancer (PROC), epithelioid mesothelioma, lung adenocarcinoma, pancreatic adenocarcinoma, colorectal cancer, cholangiocarcinoma, and gastric/GEJ adenocarcinomas will be enrolled in one of approximately 9 dose escalation cohorts to assess the safety and tolerability of CT-95, as well as determine the maximum tolerated dose (MTD) or other recommended dose(s) for expansion (RDE[s]) for further dose expansion cohorts.

Participants will receive CT-95 as a single agent administered once weekly (QW) intravenously (IV) over a 4-week cycle.

Phase 1b Dose Expansion: The RDE(s) of CT-95 determined in Phase 1a will be evaluated in 2-4 indication-specific expansion cohorts of up to 20 subjects each (i.e. up to 80 participants total). Different indications, dose levels, and/or schedules may be explored. The expansion doses and/or dosing schedules for Phase 1b will be determined by Sponsor in conjunction with SRC based upon all available safety, PK, PD, biomarker, and preliminary efficacy data from Phase 1a.

Inclusion Criteria:

• ECOG 0 or 1
• Subjects with evaluable disease per RECIST 1.1 or mRECIST
• Subjects with adequate organ function.
• Subjects with advanced cancers associated with mesothelin expression

Exclusion Criteria:

• Uncontrolled significant active infection or any medical or other condition that in opinion of the investigator would preclude the subject's participation in the study.
• Prior treatment with MSLN-targeted CD3 or chimeric antigen receptor T cell (CAR-T) therapy
• Concurrent participation in another investigational clinical trial.
• Evidence of leptomeningeal disease