A Phase 1/2 Trial Of Th-302 And Dexamethasone Without Or With Bortezomib (Tbord) In Patients With Relapsed/Refractory Multiple Myeloma

Background: TH-302 is a 2-nitroimidazole prodrug of the DNA alkylator bromo-isophosphoramide mustard that is selectively activated under hypoxic conditions. TH-302 has demonstrated anti-myeloma activity in preclinical models both in vitro and in vivo, as well as synergistic cytotoxic activity with bortezomib (Bor) in vitro. An ongoing Phase 1/2 study (NCT01522872) investigates TH-302 with dexamethasone (dex) without Bor or with Bor (TBorD) in patients (pts) with relapsed/refractory multiple myeloma (RR MM). The maximum-tolerated dose (MTD) of TH-302 plus dex was previously established at 340 mg/m2. We report preliminary results from pts treated at the MTD of TH-302 plus dex; enrollment in the TBorD arm is ongoing.