Good news on an experimental anticancer drug made by
wasn't good enough to please investors. In recent trading Monday, the company's shares were off $1.69, or nearly 7%, to $23.07.
On Saturday, Onyx and its partner, German drugmaker
, said their researchers have started a Phase III clinical trial of BAY 43-9006 on patients with advanced kidney cancer.
The Phase II data on BAY 43-9006 is still preliminary but paints the picture of a very active drug, and one with the ability to shrink tumors in a greater percentage of advanced kidney cancer patients than other, rival targeted cancer drugs also in development.
The Phase III study, now under way, will determine whether the drug's activity translates into helping kidney cancer patients actually live longer, the gold standard for cancer drug efficacy.
"These data are preliminary, but they appear promising and warrant further exploration of safety and efficacy in Phase III trials," Susan Kelley, vice president at Bayer's U.S. oncology division said in a prepared statement.
Although the data were positive, expectations were high. The stock has been bid up over the past year -- it traded last October at $3.59. Some investors also were hoping to hear the company detail plans for an accelerated filing with the Food and Drug Administration.