Laubach JP, Liu CJ, Raje NS, Yee AJ, Armand P, Schlossman RL, Rosenblatt J, Hedlund J, Martin M, Reynolds C, Shain KH, Zackon I, Stampleman L, Henrick P, Rivotto B, Hornburg KTV, Dumke HJ, Chuma S, Savell A, Handisides DR, Kroll S, Anderson KC, Richardson PG, and Ghobrial IM
Purpose: The presence of hypoxia in the diseased bone marrow presents a new therapeutic target for multiple myeloma. Evofosfamide (formerly TH-302) is a 2-nitroimidazole prodrug of the DNA alkylator, bromo-isophosphoramide mustard, which is selectively activated under hypoxia. This trial was designed as a phase I/II study investigating evofosfamide in combination with dexamethasone, and in combination with bortezomib and dexamethasone in relapsed/refractory multiple myeloma., Patients and Methods: Fifty-nine patients initiated therapy, 31 received the combination of evofosfamide and dexamethasone, and 28 received the combination of evofosfamide, bortezomib, and dexamethasone. Patients were heavily pretreated with a median number of prior therapies of 7 (range: 2-15). All had previously received bortezomib and immunomodulators. The MTD, treatment toxicity, and efficacy were determined., Results: The MTD was established at 340 mg/m 2 evofosfamide + dexamethasone with dose-limiting mucositis at higher doses. For the combination of evofosfamide, bortezomib, and dexamethasone, no patient had a dose-limiting toxicity (DLT) and the recommended phase II dose was established at 340 mg/m 2 . The most common ≥grade 3 adverse events (AE) were thrombocytopenia (25 patients), anemia (24 patients), neutropenia (15 patients), and leukopenia (9 patients). Skin toxicity was reported in 42 (71%) patients. Responses included 1 very good partial response (VGPR), 3 partial response (PR), 2 minor response (MR), 20 stable disease (SD), and 4 progressive disease (PD) for evofosfamide + dexamethasone and 1 complete response (CR), 2 PR, 1 MR, 18 SD, and 5 PD for evofosfamide + bortezomib + dexamethasone. Disease stabilization was observed in over 80% and this was reflective of the prolonged overall survival of 11.2 months., Conclusions: Evofosfamide can be administered at 340 mg/m 2 twice a week with or without bortezomib. Clinical activity has been noted in patients with heavily pretreated relapsed refractory multiple myeloma., (©2018 American Association for Cancer Research.)