Despite a “thumbs-up” from a Food and Drug Administration (FDA) advisory panel on GlaxoSmithKline and Valeant’s new epilepsy drug Potiga (ezogabine), federal regulatory review of the drug has been pushed back three months. The panel this week reviewed three clinical studies on the drug and found that it helped to control seizures when used as an add-on treatment in certain epilepsy patients. The only red flag was urinary side effects, which the majority of the panel believed could be mitigated by patient monitoring.
The FDA is not required to follow the panel’s recommendations, but it usually does. GlaxoSmithKline and Valeant said the agency has extended its target date under the Prescription Drug User Act from August 20 to November 30, giving it more time to review study data. Under that law, drug companies pay extra fees to speed up the federal review process.
More than 2 million people have been diagnosed with epilepsy or have suffered from seizures, and one-third of epileptics cannot control their disorders with medications currently available. Neurological patients often are more sensitive to medications and are often more susceptible to side effects. Patients who have their seizure disorders controlled by medication are not advised to switch formulations, including from a brand name to a generic, because they could experience a return of symptoms.
This problem has escalated recently with the introduction of generic versions of the anti-epileptic drug Keppra in 2009. Recently, patients who have controlled their seizure disorder with the brand name Keppra found that they experienced seizures and other side effects after switching to a generic version of the drug.