Threshold Pharmaceuticals Inc. tumbled the most in almost three years after its experimental pancreatic cancer drug didn’t significantly improve patients’ overall chance of survival.
Threshold fell 20 percent to $7 at 4 p.m. New York time, in its biggest drop since November 2009. The shares of the South San Francisco, California-based company had increased more than five-fold in the 12 months through yesterday.
Patients treated with Threshold’s TH-302 plus chemotherapy had a median survival of 9.2 months compared with 6.9 months for those treated with only chemotherapy in the second of what are typically three phases of clinical studies needed for regulatory approval, Threshold said in a statement today. The trial wasn’t designed to detect a statistically significant improvement in overall survival, the company said.
“We are pleased with the overall consistency of results from this study demonstrating activity of TH-302 and, as a consequence, a randomized Phase 3 trial of TH-302 in patients with advanced first-line pancreatic cancer is planned to be initiated together with our partner Merck KGaA,” Barry Selick, chief executive officer of Threshold, said in the statement.
The study met its primary goal in demonstrating a 63 percent improvement in progression-free survival for patients treated with TH-302 plus chemotherapy versus chemotherapy alone, Threshold said in February.
Threshold plans to present the secondary overall survival results at the European Society for Medical Oncology 2012 Congress that starts this month in Vienna.