TORL-1-23, a CLDN6-targeted ADC, showed responses in heavily pretreated, CLDN6-positive advanced solid tumors, including platinum-resistant ovarian cancer, with a well-tolerated safety profile. The ORR was 26% at doses <2.4 mg/kg, 42% at 2.4 mg/kg, and 31% at 3.0 mg/kg, with a complete response rate of 4% at the highest dose. Neutropenia risk was mitigated by prophylactic pegfilgrastim, and the MTD was not yet reached.