October 22, 2009 (Baltimore, Maryland) — A new analysis of 3 clinical trials suggests adjunctive lacosamide may be beneficial for partial-onset seizures. The results were presented here at the 134th annual meeting of the American Neurological Association. The new antiepileptic marketed by UCB as Vimpat has already been approved in the United States and Europe for this indication.
The findings are based on the phase 2 and 3 studies that first garnered lacosamide marketing approval. The fact that this new analysis also suggests efficacy is not surprising, but what is perhaps surprising is how well the placebo group fared in the study.
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| Dr. Edward Faught |
"By combining the 3 trials, we had a large enough sample to improve statistical power," coauthor Edward Faught, MD, from the University of Alabama at Birmingham, told Medscape Neurology. "We were also able to assess seizure reductions in the various groups."
The group was led by Jouko Isojärvi, MD, from Schwarz Biosciences, a division of UCB, the drug's manufacturer. The study was presented during a poster session at the meeting.
Pooled Analysis of 3 Trials
Investigators looked at 935 participants from the clinical development program for lacosamide. This included 3 multicenter, randomized, double-blind, placebo-controlled, fixed-dose efficacy trials. The studies were similarly designed, and each trial had a 12-week maintenance phase.
Researchers assessed efficacy in the new analysis by seizure type using pooled data from participants' seizure diaries for the clinical trials.
Investigators report that the largest reductions over placebo in the lacosamide treatment groups occurred in the 2 most commonly reported seizure types — complex partial and partial seizures with secondary generalization.
Median Reduction in Seizure Frequency*
| Group | Complex Partial Seizures (%) | Partial With Secondary Generalization (%) |
| Placebo | 22.4 | 32.5 |
| Lacosamide 200 mg | 34.1 | 50.0 |
| Lacosamide 400 mg | 40.8 | 55.6 |
| Lacosamide 600 mg | 41.9 | 85.9 |
*From 28 days from baseline to maintenance phase.
Response to Treatment of 50% or More*
| Group | Complex Partial Seizures (%) | Partial With Secondary Generalization (%) |
| Placebo | 29.2 | 36.6 |
| Lacosamide 200 mg | 35.8 | 50.9 |
| Lacosamide 400 mg | 43.0 | 53.5 |
| Lacosamide 600 mg | 41.8 | 64.7 |
*From baseline to maintenance phase.
No Difference for Simple Partial Seizures
However, for simple partial seizures, the reductions in frequency and improved responder rates between the lacosamide and placebo groups did not differ.
Dr. Faught said this may represent a shift in effectively treated patients from complex partial seizures and partial seizures with secondary generalization to less clinically severe attacks.
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| Dr. Daniel Lowenstein |
Daniel Lowenstein, MD, from the University of California–San Francisco said he prescribes lacosamide from time to time. Dr. Lowenstein is the chair of the scientific program advisory committee for the American Neurological Association. "I use lacosamide in patients who have been resistant to previously available antiepileptics," he said during an interview.
Dr. Lowenstein said he is grateful for any new information about this recently approved drug. Formerly known as erlosamide, the product was developed as adjunctive treatment of partial-onset seizures and diabetic neuropathic pain.
Lacosamide is thought to exert its therapeutic effects through a different mechanism of action by enhancing slow inactivation of sodium channels. In some patients, it can cause dizziness, blurred or double vision, nausea, headache, rash, or allergic reactions.
Most people participating in the lacosamide trials reported using 4 or more antiepileptic drugs in their lifetime. Most people were receiving 2 or 3 concomitant therapies at the time of the studies.
Carbamazepine and lamotrigine were the 2 most frequently reported therapies.
Most Frequent Concomitant Antiepileptic Drugs
| Drug | Rate (%) |
| Carbamazepine | 35 |
| Lamotrigine | 31 |
| Levetiracetam | 29 |
| Valproic acid | 24 |
| Topiramate | 22 |
| Oxcarbazepine | 18 |
| Phenytoin | 14 |
"Lacosamide is a pretty straightforward drug, and it's easy to add in refractory patients," Dr. Faught told Medscape Neurology. "It will either work or it won't."
Session attendee Jingxia Dang, MD, from First Affiliated Hospital of Medical College in Xi'an, China, criticized the poster. "This is a very commonly done study," she said, "but I am not confident the conclusions are accurate, given the strong showing in the placebo group."
Dr. Dang said that based on these results, she would hesitate to add lacosamide.
This study was supported by UCB Incorporated. Lead author Dr. Jouko Isojärvi works for Schwarz Biosciences, a division of UCB.
American Neurological Association 134th Annual Meeting: Poster M44. Presented October 12, 2009.
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Cite this: Lacosamide Add-On May Reduce Partial-Onset Seizures - Medscape - Oct 22, 2009.
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