FDA Approves Once-Daily Extended Release Lamotrigine for Epilepsy


NEW YORK -- June 1, 2009 -- The US Food and Drug Administration (FDA) has approved lamotrigine extended-release (XR) tablets (Lamictal XR) as a once-daily add-on therapy for patients with epilepsy aged 13 years or older with partial onset seizures.

"Many patients require multiple doses of 1 or more medications to control their epilepsy, which makes taking their medicines even more challenging," said Dean Naritoku, MD, Department of Neurology, University of South Alabama, Mobile, Alabama. "[Lamotrigine XR] is an important once-daily advance for patients with epilepsy who still experience seizures while taking their current therapy."

The approval was based on data from an international, multicentre, randomised, double-blind, placebo-controlled trial (ARMOR) of 236 patients aged 13 years or older with inadequately controlled partial seizures, who were taking a stable regimen of 1 or 2 antiepileptic drugs (AEDs).

Patients had experienced 8 or more partial seizures during the 8-week baseline phase of the study. Patients in the baseline period were experiencing 4 to 6 seizures per week prior to being randomised to either lamotrigine XR or placebo. The treatment period of the study consisted of a 7-week Escalation Phase and a 12-week Maintenance Phase.

Study results showed that lamotrigine XR reduced partial seizures by 47%, compared with 25% with placebo over the entire 19-week treatment period (P = .0001).

A second study (COMPASS) evaluated the conversion from the immediate-release form of lamotrigine given twice daily to the same total daily dose of lamotrigine XR given once daily in 44 patients aged 13 years or older with epilepsy.

Patients enrolled in the study were divided into 3 treatment groups based on the type of adjunctive AED they were taking.

Results showed that patients could be switched from the immediate-release formulation of taken twice daily to the same total daily dose of lamotrigine XR taken once daily while maintaining comparable minimum blood levels of lamotrigine, regardless of the other AEDs being taken concurrently.

No serious rashes were observed in either treatment group in both studies. However, the risk of serious rash caused by lamotrigine XR is not expected to differ from that of with the immediate-release formulation.

SOURCE: GlaxoSmithKline