Challenges in the Clinical Development of New Antiepileptic Drugs

The very nature of epilepsy makes the clinical development of new antiepileptic drugs a lengthy and costly process. The underlying disease mechanisms are largely unknown, reflecting the paucity of animal models that mirror the human condition. The risks of untreated epilepsy usually preclude the use of placebo as a control treatment except in patients receiving background medication. Thus, new AEDs must first display a treatment effect in patients with seizures known to be resistant to drug therapy, using study designs that are confounded by the potential pharmacodynamic and pharmacokinetic interactions associated with polytherapy. Moreover, the unpredictable nature of epilepsy often means lengthy clinical trials. Clinical development for antiepileptic drugs is inevitably more complex and time-consuming than for many other drugs. As a result the interval between product approval and loss of patent is often shorter. Creative methods of accelerating the development process without compromising the quality of research are needed.