Glaxo, based in London, and Valeant, based in Mississauga, Ontario, are evaluating the Food and Drug Administration’s decision not to approve the medicine, ezogabine, the companies said today in a statement. Glaxo, the U.K.’s biggest drugmaker, bought global marketing rights to the product from Valeant in 2008. The FDA on Aug. 30 had delayed a decision.
The experimental drug was aimed at the estimated 30 percent of patients who can’t control seizures with current epilepsy medicines, leading to disability and an unsatisfactory quality of life, Glaxo and Valeant said. More than 2 million people in the U.S. have been diagnosed with epilepsy or have suffered from an unprovoked seizure, according to the National Institute of Neurological Disorders and Stroke, based in Bethesda, Maryland.
The companies “believe that these items can be addressed” and “are working for a timely response to the FDA as soon as possible in 2011,’ Glaxo and Valeant said in the statement.
Ezogabine has the potential to generate annual sales of more than $600 million, according to analysts surveyed by Bloomberg. If approved, Glaxo’s sales of the drug, called retigabine outside the U.S., would be 334.5 million pounds ($532.8 million) in 2014, according to the average estimate of two analysts surveyed by Bloomberg. Two analysts projected the product would have brought in $117.9 million in revenue for Valeant that same year.
Valeant shares fell 2.9 percent to $26.15 at 6:33 p.m. in extended trading after closing up $1.05, or 4 percent, to $26.92, in New York Stock Exchange composite trading.
Robin Gaitens, a Glaxo spokeswoman, declined comment beyond the companies’ statement on the FDA action.
Ezogabine acts on the brain’s potassium channel, controlling nerve cells so they don’t become over-stimulated and cause a seizure. Most current drugs regulate sodium or calcium channels.
An FDA advisory panel concluded Aug. 11 that ezogabine worked as an add-on treatment and that bladder blockage, a side effect seen in studies, can be controlled by monitoring patients.
The treatment was linked in studies to cases of urinary retention, an inability to empty the bladder, which may cause infections or permanent bladder and kidney damage. While most cases were reversible, FDA staff called it a ‘‘significant safety issue” in a report released before the panel meeting.
The FDA is asking for “some end-of-approval type requirements,” Laura Little, a spokeswoman for Valeant, said in a telephone interview. She declined to elaborate on those requirements and said the companies anticipate gaining U.S. clearance for the treatment in the first quarter of 2011.
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