Spectrum Pharmaceuticals Inc's experimental bladder cancer treatment apaziquone is not effective in delaying the time to recurrence of the disease, an advisory committee to the U.S. Food and Drug Administration concluded on Wednesday.
Spectrum's shares fell 6.2 percent to $5.15.
The committee, which convened to advise the FDA on whether to approve the drug, voted unanimously that the treatment has no more effect on the disease than a placebo over a two-year period.
The FDA is not obliged to follow the advice of its advisory committees but typically does so. The agency is scheduled to make its decision by Dec. 11.
Apaziquone is inserted directly into the bladder following surgery to remove tumors. In 2012, two late-stage clinical trials failed to meet their main goal.
The company subsequently initiated a new late-stage trial which it said incorporated input from the FDA and included pooled data from its two previous trials. The pooled data, as opposed to data from individual trials, showed a reduction in disease recurrence over two years.
The new trial protocol called for patients to be given either one instillation of the drug, or two, or a placebo. In the previous late-stage trials all patients received just one installation or a placebo.
Apaziquone is activated by enzymes that are over-expressed in bladder cancer cells.
Most bladder cancers are treated with surgery, either alone or with other treatments. Surgery can often remove early stage bladder tumors, but new tumors frequently form in other parts of the bladder. Some 80 percent of patients experience a recurrence within 5 years, many within two years.
Removing the entire bladder avoids this but the procedure can have a significant impact on a patient's quality of life since new methods are needed to remove urine from the body. This typically requires reconstructive surgery to create a new receptacle, inside or outside the body, that the patient has to drain.
(Reporting by Toni Clarke in Washington; Editing by Alan Crosby)