shares slid after regulatory documents indicated that its lung cancer drug Tarceva did not show a clinically significant benefit when used to treat pancreatic cancer.
Based on a trial comparing Tarceva plus gemcitabine chemotherapy vs. a placebo plus gemcitabine in patients with advanced metastatic pancreatic cancer, the Food and Drug Administration concluded that while some analyses showed statistically significant differences between the treatments, there were no "clinically meaningful" differences between tumor shrinkage, duration of tumor response or survival.
The median survival for patients receiving Tarceva was seven months vs. about six months for patients receiving a placebo, FDA documents released Monday said. Additionally, no differences were observed in the reduction of the tumor size, according to the FDA clinical review.
Shares of OSI fell $1.35, or 4.2%, to $30.95, which puts the stock under its lowest close of the last 52 weeks at $31.66. The high for the last year was $74.95.
OSI, based in Melville, N.Y., said its results are clinically meaningful. Tarceva trials showed a 27% improvement in survival, and the drug reduced the risk of death by 21% compared with placebo, the company said in its own briefing documents submitted to the FDA.
An OSI representative said the company wouldn't otherwise comment prior to the committee's review.
The drug was granted
priority review for use against pancreatic cancer in July. The FDA's oncology drugs advisory committee meets Wednesday to review the trial data.
Tarceva received FDA approval last November to treat patients with locally advanced or metastatic nonsmall-cell lung cancer after at least one prior chemotherapy regimen failed.
At a 99% mortality rate, pancreatic cancer has the highest among cancer types. Metastatic pancreatic cancer has a five-year survival rate of only 1.8%.
Tarceva was co-developed by
. Genentech's shares fell 73 cents to $91.63.