Congress report 7: AEDs - the future of drug development

The session - chaired by Profs Wolfgang Löscher (Germany) and Emilio Perucca (Spain)- was entitled "Why do new anti epileptic drugs not deliver and what to do about it?" During the session, Prof Martin Brodie (UK) explored the history of how drug trials are performed and why such trials are not as helpful as they might be in offering useful information that translates into clinical practice.

Prof Brodie first cited the advantages of the current system. Randomised controlled trials minimise any bias in scientific results and do offer useful information about effective dosages and tolerability. Unfortunately, there are many disadvantages to randomised controlled trials, including a lack of information on long-term efficacy and tolerability. Given that many people with epilepsy will be taking their medications all their lives, this information would be incredibly useful in clinical practice.

Despite the introduction of a variety of the so-called 'new designer' AEDs (beginning with the introduction of vigabatrin in 1989), the pharmacological treatment of epilepsy remains largely unchanged. Although new drugs may have fewer side-effects, the percentage of people with epilepsy who never become seizure-free is roughly the same.

AEDs in the pipeline

The session continued with a presentation from Prof H Steve White (USA), whose career has included the development and assessment of many of the newer AEDs. He clarified exactly who remains under served by the current system of drug trials.

Such people include those whose epilepsy is drug-resistant, children living with the condition, the elderly and people with epilepsy who have other comorbid conditions. Prof White admitted that, despite some very effective laboratory models of epilepsy, new methods of trialling AEDs may necessary in trying to accommodate these patient groups. New models should certainly attempt to more closely reflect clinical practice.

Prof White said: "When it comes to screening for efficacy, the 'reductionist' approach employed in the past has attempted to oversimplify a very complex condition."

Treat the condition, not the symptoms

A presentation from session chair, Prof Wolfgang Löscher, went on to call to a completely new approach to the kinds of drugs that are being developed.

At the moment, AEDs all attempt to do the same thing - control the seizures that are only the symptoms of brain dysfunction. Prof Löscher pointed out that we need to develop a new approach: curing the epilepsy, rather than its symptoms. Prof Löscher believes that represents the future of epilepsy drugs - those drugs referred to not as anti-epileptic drugs, but anti-epileptogenic drugs.

It appears that only a fairly radical change of approach will lead to a genuine pharmacological cure for epilepsy. This may offer a genuine chance to effectively treat the 30-40 per cent of people with epilepsy who currently do not respond to drug treatment.