A Phase 1/2 Study of evofosfamide, A Hypoxia-Activated Prodrug with or without Bortezomib in Subjects with Relapsed/Refractory Multiple Myeloma

Mené sur 59 patients atteints d'un myélome multiple récidivant ou réfractaire (nombre médian de thérapies antérieures : 7), cet essai de phase I/II évalue la dose maximale tolérée, l'efficacité, du point de vue du taux de réponse et de la survie globale, et la toxicité de l'évofosfamide, un pro-médicament activé par hypoxie, utilisé en combinaison avec la dexaméthasone avec ou sans bortézomib

Clinical Cancer Research, sous presse, 2018, résumé

Résumé en anglais

Purpose: The presence of hypoxia in the diseased bone marrow presents a new therapeutic target for multiple myeloma (MM). Evofosfamide (formerly TH-302) is a 2-nitroimidazole prodrug of the DNA alkylator bromo-isophosphoramide mustard that is selectively activated under hypoxia. A phase 1/2 study investigating evofosfamide in combination with dexamethasone (EvoD) and in combination with bortezomib and dexamethasone (EvoBorD) in relapsed/refractory MM.

Experimental Design: 59 patients initiated therapy, 31 received EvoD and 28 received EvoBorD. Pts were heavily pre-treated with a median number of prior therapies of 7 (range: 2-15). All had previously received bortezomib and immunomodulators. The maximum tolerated dose (MTD), treatment toxicity, and efficacy were determined.

Results: The MTD was established at 340 mg/m2 Evo+D with dose limiting mucositis at higher doses. For EVOBorD, no patient had a dose limiting toxicity and the recommended phase 2 dose was established at 340 mg/m2. The most common ≥ Gr 3 adverse events were thrombocytopenia (25 patients), anemia (24 patients), neutropenia (15 patients) and leukopenia (9 patients). Skin toxicity was reported in 42 (71%). Responses included 1 VGPR, 3 PR, 2 MR, 20 SD and 4 PD for EvoD and 1 CR, 2 PR, 1 MR, 18 SD and 5 PD for EvoBorD. 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/m2 twice a week with or without bortezomib. Clinical activity has been noted in patients with heavily pre-treated relapsed refractory MM.