LIFA was administered to patients with non-small cell lung cancer (NSCLC) and platinum-resistant ovarian cancer (PROC), once every 3 weeks...The pharmacokinetic profile was dose proportional. At active doses ≥1.8 mg/kg, partial responses were observed in four of 51 (8%) patients with NSCLC and 11 of 24 (46%) patients with PROC per RECIST. All RECIST responses occurred in patients with NaPi2b-high by IHC...LIFA exhibited dose-proportional pharmacokinetics and an acceptable safety profile, with encouraging activity in patients with PROC at the single-agent RP2D of 2.4 mg/kg.