upifitamab rilsodotin

Upifitamab rilsodotin is an investigational **NaPi2b-targeting antibody-drug conjugate** developed by Mersana Therapeutics for ovarian cancer and other NaPi2b-expressing solid tumors. It was built on Mersana's **Dolaflexin** ADC platform and is designed to bind the sodium-dependent phosphate transport protein **NaPi2b** on tumor cells, enabling intracellular delivery of a cytotoxic payload after target engagement. Clinical development focused primarily on recurrent ovarian cancer, including platinum-resistant disease in the Phase 1b/2 **UPLIFT** trial and platinum-sensitive disease in the Phase 3 **UP-NEXT** and Phase 1 **UPGRADE-A** studies. Development was later deprioritized after UPLIFT failed its primary endpoint and following safety concerns including serious bleeding events that led to a partial FDA clinical hold on platinum-sensitive ovarian cancer studies.

Brand names

UpRi

Other names

XMT-1536XMT1536XMT 1536upifitamab rilsodotin