TUB-040 (NaPi2b Exatecan ADC) Delivers 61% cORR in Platinum-Resistant Ovarian Cancer

TUB-040 is a NaPi2b-targeted antibody–drug conjugate with a DAR8 exatecan topoisomerase I payload via a cleavable P5 linker, evaluated as every-3-week monotherapy in biomarker-unselected platinum-resistant ovarian cancer in NAPISTAR 1-01 (Phase 1/2a; NCT06303505). As of December 1, 2025, efficacy-evaluable patients treated at 1.67–3.3 mg/kg (n=46; median 4 prior lines; 76% prior PARPi; 84% prior bevacizumab; 13% prior mirvetuximab) achieved uORR 63%, cORR 60.9% including 2 cCRs, DCR 96%, and CA-125 response in 81%, with 90% of responses ongoing at cutoff. Safety was mainly GI and cytopenias, including nausea 78%, fatigue 54%, grade ≥3 neutropenia 26%, grade ≥3 anemia 13%, no fatal TEAEs, no TEAE-related discontinuations, and grade 1 pneumonitis in 6.5%; the response rate is well above typical single-agent chemo ORRs around 10–15% and above mirvetuximab’s 32.4% ORR in FRα-high PROC.