TUSTIN, Calif. (AP) -- Shares of Peregrine Pharmaceuticals Inc. lost about 25 percent of their value Friday after the company said its cancer drug bavituximab didn't work better than two older chemotherapy drugs as a treatment for lung cancer.
The company is evaluating bavituximab as a primary treatment for advanced non-small cell lung cancer in a mid-stage clinical trial. Based on scans evaluated by independent radiologists, Peregrine said patients who were treated with bavituximab and two other chemotherapy drugs had median survival of 6.7 months before death or disease progression. Patients only treated with the other drugs, carboplatin and paclitaxel, had their disease progression delayed by 6.4 months.
Peregrine said patients in the chemotherapy portion of the study survived longer than expected, which is why there was little different between the two groups of patients.
Peregrine shares lost 23 cents, or 25.6 percent, to 67 cents in afternoon trading. Earlier shares traded at an all-time low of 63 cents.
The drug appeared to do better when the scans were reviewed by investigators in the study, as patients treated with bavituximab had progression-free survival of 5.8 months and patients treated with just chemotherapy had 4.6 months of progression-free survival. That was a 26 percent improvement.
The company will report data on patients' overall survival in the second half of 2012. Peregrine Pharmaceuticals is also studying bavituximab as a secondary treatment for lung cancer, and as a treatment for cancers of the pancreas, liver, prostate, and breast.