GlaxoSmithKline (GSK) and Valeant Pharmaceuticals International have entered into an exclusive worldwide collaboration agreement for the investigational drug retigabine, a first in class neuronal potassium channel opener for treatment of adult epilepsy patients with refractory partial onset seizures.
Retigabine has shown robust efficacy and safety as demonstrated in two large, completed phase-III trials conducted in patients with refractory epilepsy receiving treatment with up to three antiepileptic drugs (AEDs). Valeant and GSK plan to file a New Drug Application in the US and a Marketing Authorisation Application in Europe by early 2009. The retigabine programme also includes an ongoing study in patients with post-herpetic neuralgia (PHN), a painful and common complication of shingles.
Under the terms of the agreement, Valeant will grant GSK worldwide development and commercialisation rights to retigabine, VRX698 and the other back-up compounds from the potassium channel opener discovery programme in exchange for an upfront payment of $125 million to Valeant.
Additionally, GSK will pay Valeant up to $545 million based on the achievement of certain regulatory, development and commercialisation milestones and the development of additional indications for retigabine. Valeant will co-commercialise with GSK and will share up to 50 per cent of net profits within the US, Canada, Australia, New Zealand and Puerto Rico, and will receive up to a 20 per cent royalty on net sales of retigabine outside those regions. The two companies will jointly fund all global research and development expenses for retigabine, and GSK will completely fund the development of VRX698 and the other back-up compounds from the potassium channel opener discovery programme. Valeant could receive up to an additional $150 million based on the achievement of certain regulatory, development and commercial milestones for VRX698 and the back-up compounds and double-digit royalties on worldwide sales.
"GSK is looking forward to working with Valeant to provide important medicines like retigabine to the medical community and to the patients we serve," commented Steve Stefano, senior vice president, GSK US NeuroHealth Division. "There is a significant need for novel anti-epileptic drugs, as almost one-third of patients with epilepsy continue to experience seizures despite treatment with currently available medications. We believe that retigabine could potentially play a significant role in improving the management of epilepsy and is a welcome addition to GSK's portfolio."
"We were pleased with the significant interest shown in retigabine, and we have selected GSK as a collaborator because we believe they are ideally suited and strongly committed to the continued development of this important compound," stated J Michael Pearson, chairman and chief executive officer of Valeant. "GSK's development expertise and strong commercial infrastructure will be critical to maximising the worldwide potential of retigabine. We believe this collaboration will strengthen our ability to bring this medicine to patients suffering from epilepsy and a variety of other conditions."
Epilepsy, defined by recurrent unprovoked seizures, is a change in sensation, awareness, or behaviour brought about by an electrical disturbance in the brain. The kind of seizure a person has depends on which part and how much of the brain is affected by the disturbance that produces seizures.
Potassium channels are one of the voltage-gated ion channels found in neuronal cells and are an important determinant of neuronal activity.
GlaxoSmithKline is one of the world's leading research-based pharmaceutical and healthcare companies - is committed to improving the quality of human life by enabling people to do more, feel better and live longer.
Valeant Pharmaceuticals International is a global specialty pharmaceutical company that develops, manufactures and markets a broad range of pharmaceutical products primarily in the areas of neurology, infectious disease and dermatology.