| Threshold Pharmaceuticals announced results from two clinical trials related to Threshold's clinical stage hypoxia-activated prodrug, TH-302. The two clinical trials are both evaluating the safety and preliminary efficacy of TH-302 in patients with advanced solid tumors; one in combination with other chemotherapy agents (the 402 trial) and the other with TH-302 as monotherapy (the 401 trial). In this presentation, results from patients with metastatic castration-resistant prostate cancer, or CRPC, were discussed. In the 401 trial, 8 patients with metastatic CRPC enrolled in the trial and received TH-302 as monotherapy. Six of 7 evaluable patients had stable disease, or SD, at their initial tumor assessment after Week 8. In the 401 clinical trial mucosal and skin toxicity were dose-limiting while hematologic toxicity was minimal. In the 402 trial, docetaxel is one of three chemotherapeutic regimens being evaluated in combination with TH-302. Data from the first 6 patients with metastatic CRPC enrolled in the trial were presented. Four patients had at least one evaluable post-treatment tumor assessment. Three of 4 patients had SD or better including one patient with a confirmed partial response. One of 4 patients discontinued with progressive disease with the onset of bone metastases. Four patients had prostate specific antigen - PSA - assessments after at least 2 cycles of therapy with drop in median PSA of 62 percent. Three of 4 patients had a drop in PSA of at least 50 percent. Skin and mucosal toxicities were not dose limiting. Enrollment of patients with metastatic CRPC continues in the 402 trial with the objective of better defining the possible therapeutic benefit of TH-302 combined with docetaxel in this setting. :theflyonthewall.com |
