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

(RTTNews) - Threshold Pharmaceuticals, Inc. (THLD) Friday reported clinical data from the ongoing Phase 1/2 trial of its investigational hypoxia-activated prodrug, TH-302, in combination with bevacizumab in patients with recurrent glioblastoma following progression on single-agent bevacizumab.

The trial evaluated the safety and tolerability of TH-302, determining the dose-limiting toxicities and the maximum-tolerated dose of TH-302, and assessing preliminary signals of clinical activity in patients with bevacizumab-refractory recurrent glioblastoma. A total of 17 patients were treated with bevacizumab 10 mg/kg every two weeks and TH-302 dose escalated 240-670 mg/m2 every two weeks until disease progression. Patients had received a median of three prior systemic anticancer regimens including both chemoradiation and bevacizumab.

According to Response Assessment in Neuro-Oncology criteria, out of 17 patients, best responses included one complete response and three partial responses for a response rate of 24%, and eight stable disease assessments for a clinical benefit rate of 65%; five patients had progressive disease. The longest disease stabilization is ongoing at 30 months.

Patients treated with TH-302 plus bevacizuma showed a median progression-free survival or PFS for 3.1 months, while these patients experienced PFS of 2.4 months on their first bevacizumab regimen. The 4-month PFS rate was 26%. Median overall survival of patients treated with TH-302 plus bevacizumab was 4.9 months.

Further, the company said the enrollment at 670 mg/m2 TH-302 in combination with bevacizumab is ongoing.