July 17, 2006

Threshold Pharmaceuticals announced that its Phase II and III trials of TH-070 did not meet their primary endpoints of symptomatic improvement as measured by the International Prostate Symptom Score. The Phase II trial did not generate a statistically significant dose response relationship, and the Phase III trial did not achieve a statistically significant difference between TH-070 and placebo. Based on the safety and efficacy results of these trials, Threshold plans to discontinue development of TH-070 for benign prostatic hyperplasia (BPH).

The Phase II randomized, placebo-controlled, double-blind trial enrolled men with moderate to severe BPH. The primary objectives of this study were to determine the dose-response relationship of TH-070 with respect to symptomatic improvement and to evaluate other efficacy endpoints and the safety at the different doses.

The Phase III trial also enrolled men with moderate to severe BPH. The primary objective was to evaluate the efficacy of TH-070 compared with placebo as measured by IPSS. Dosing in this trial was prematurely discontinued when the company announced the partial clinical hold in the U.S. TH-070 program due to adverse events relating to elevated liver enzymes.