First-in-Human Dose Expansion Study of XMT-1536 in Cancers Likely to Express NaPi2b

This is a multi-center study of XMT-1536 (upifitamab rilsodotin) in patients with tumors likely to express NaPi2b, focusing on patients with platinum-resistant ovarian cancer and non-small cell lung cancer, adenocarcinoma subtype. XMT-1536 (upifitamab rilsodotin) was administered as an intravenous infusion once every four weeks. Enrollment into the EXP segment consisted of 2 parallel cohorts of patients to confirm the dose that was identified in DES and estimate the objective response rate in each patient population. All adverse events were graded according to the National Cancer Institute (NCI) Common Terminology Criteria version (CTCAE v5.0). Throughout the study, pharmacokinetics were measured using proprietary assays developed by Mersana. Anti-cancer activity were measured via RECIST.