LONDON (dpa-AFX) - Canadian drugmaker Valeant Pharmaceuticals International, Inc. (VRX, VRX.TO) and UK-based healthcare giant GlaxoSmithKline Plc (GSK, GSK.L), Monday announced that their epilepsy drug Potiga (ezogabine) has been approved by the US regulators as a controlled substance under the Controlled Substances Act.
The FDA has recommended to place Ezogabine on the controlled substance schedule. The Federal Drug Enforcement Administration is reviewing the final classification, and the tablet will not be available until this process is complete. The companies expect the drug to be available in U.S. pharmacies by the end of this year.
Epilepsy is a common chronic neurological disorder characterized by seizures. The FDA approved the pill as an adjunctive treatment for partial-onset seizures in patients aged 18 years and older. Partial-onset seizures begin in one side of the brain.
Ezogabine is the first potassium channel opener developed for the treatment of epilepsy. The drug is developed jointly by GlaxoSmithKline and Valeant. Last August, an FDA advisory panel unanimously backed ezogabine, with the safety of the drug being a key focus.
Commenting on ezogabine's approval by the FDA, Susan Hall, head of R&D at Valeant, stated, 'We believe this product will play a needed role in the management of partial onset seizures in appropriate patients who are uncontrolled on their current medications.'
Valeant and Glaxo stated that ezogabine's efficacy as adjunctive therapy in partial onset seizures was established in 3 controlled clinical studies involving 1,239 adult patients. The primary endpoint was percent change in seizure frequency from baseline in the double-blind treatment phase.
In clinical trials, urinary retention was reported as an adverse event in about 2 percent patients treated with ezogabine. In all studies of patients with partial-onset seizures, including open-label studies, five patients required catheterization.
According to the companies, the FDA has determined that a Risk Evaluation and Mitigation Strategy will be necessary for ezogabine in order to inform healthcare professionals of the risk of urinary retention.
In March, ezogabine received marketing authorization in the European Union. Outside of the U.S., the drug is known as retigabine with brand name Trobalt.
Ezogabine will compete with established anti-epilepsy drugs like GlaxoSmithKline's lamictal XR, Pfizer's lyrica and neurontin, and Cephalon's gabitril. Valeant expects ezogabine/retigabine to fetch peak sales of $700 million to $1.5 billion while analysts have estimated that its sales potential would be in a range of $200 million to $800 million a year.
VRX closed Friday's trading at $52.83, down $0.97, on a volume of about 2 million shares.
VRX.TO declined C$0.72 on Friday and ended trading at C$51.76, on over 393 thousands shares.
On the LS, GSK.L is trading at 1,277 pence, up 0.50 pence or 0.04 percent, on 601,402 shares.
GSK closed at $41.57 n Friday on the NYSE.
Copyright RTT News/dpa-AFX