Threshold Reports Data From Ongoing Phase 1/2 Trial Of TH-302 Plus Dexamethasone

(RTTNews) - Threshold Pharmaceuticals, Inc. (THLD) announced new preliminary data from an ongoing company-sponsored Phase 1/2 trial of its investigational hypoxia-activated prodrug, TH-302, in combination with low-dose dexamethasone in patients with relapsed/refractory multiple myeloma, a cancer of the bone marrow. The preliminary clinical benefit rate for patients treated at the maximum tolerated dose of TH-302 was 31%.

In the limited number of patients treated, it is noteworthy that objective responses were observed in this heavily pretreated patient population, including patients who received prior therapy with a proteasome inhibitor, including carfilzomib, and an immunomodulatory agent, including pomalidomide, that are typically used for advanced and later stage multiple myeloma.

Enrollment of patients with relapsed/refractory multiple myeloma in the dose-escalation and dose-expansion portions of the study is now complete, comprising 24 patients enrolled at the maximum tolerated dose of TH-302.

Based on the early signals of clinical activity, the firm looks forward to begin the final stage of the ongoing study, wherein patients would receive TH-302 and bortezomib, a combination that showed synergistic activity in preclinical models of multiple myeloma