Eligible participants include those with specific solid tumors like ovarian, endometrial, cervical, NSCLC, TNBC, pancreatic, or colorectal cancer across various cohorts. Exclusion criteria involve uncontrolled CNS metastases, carcinomatous meningitis, active infections, corneal issues, unresolved toxicities, cardiovascular disease, prolonged QTcF (≥470 ms), pneumonitis history, or pregnancy/breastfeeding.

The study has 2 phases: phase 1a dose escalation/dose optimization and phase 1b dose expansion. Dose escalation follows the mTPI-2 method. Pts are allowed to backfill to previously cleared dose levels that have demonstrated therapeutically relevant exposures or shown direct evidence of clinical activity. LY4170156 is administered intravenously Q3W; DLT evaluation period is 21 days. In dose expansion, pts with select tumor types are enrolled into 4 cohorts: PROC with high (cohort B1) and moderate/low (cohort B2) FRalpha expression and select advanced/metastatic non-ovarian cancer with high (cohort C1) and moderate/low FRalpha expression (cohort C2).

Phase 1a focuses on determining the recommended phase 2 dose (RP2D) of LY4170156, either as monotherapy or in combination with bevacizumab or carboplatin, measured by dose-limiting toxicities (DLTs) over a 21-day cycle. Phase 1b evaluates the antitumor activity of LY4170156 monotherapy, with overall response rate (ORR) assessed via RECIST 1.1 over approximately 48 months.

This section characterizes the pharmacokinetics (PK) of LY4170156 through metrics like minimum plasma concentration (Cmin) and area under the curve (AUC) over 84 days. Additionally, it evaluates preliminary antitumor activity, including ORR, duration of response (DOR), time to response (TTR), progression-free survival (PFS), and disease control rate (DCR), all assessed via RECIST 1.1, with or without bevacizumab/carboplatin, over approximately 48 months.