Strengthening the Case for Epilepsy Drug Development: Bridging Experiences from the Alzheimer's Disease Field-An Opinion.

Given the sheer number of drugs (over 20!) available for treatment of seizures, epilepsy can be considered one of the most successful areas in pharmaceutical development and especially for neuroscience. However, despite the large number of drug treatment options available for managing patients with epilepsy, there remains considerable unmet need. For example, the overall impact on seizure control has not been substantial with approximately 30% of patients remaining refractory or their seizures not adequately controlled. Also there is need for epilepsy prevention and for certain sub-populations with severe intractable epilepsy. High unmet need often drives new industry investment into therapeutic market opportunities, however the profound success of antiepileptic drugs has contributed to the hurdles for industry investment in new therapies for epilepsy. Furthermore, the payor environment has also changed with new challenges for evidence generation and demonstration of additive value above existing standard of care treatments. Challenges in translational science, in the clinical trial environment including cost and operational technical difficulty, and in the commercial environment have resulted in the pharmaceutical industry directing investments away from epilepsy into other therapeutic areas such as oncology and immunology as opportunities for higher probabilities of success and returns of investment. The neuroscience area in general is perceived a high risk area and a notable exception has been the active industry involvement in Alzheimer's disease (AD), especially for therapeutics that could modify the course or prevent AD. AD is a very high risk area with no successful efficacious treatments found to date despite recent failures, there remains promise that therapies are forthcoming. The promise is fueled by a number of innovative factors that reduced R&D challenges in the AD field and contributed to a high level of drug development activity and investment. This paper addresses hurdles facing epilepsy drug discovery and development and focuses on some key solutions that could be eased to facilitate industry interest. Similarities in drug development challenges provide opportunities that bridge experiences and learnings from AD to epilepsy. Overall, the epilepsy field is probably in a good position for advancing into the next generation therapeutics of antiepileptic drugs targeted for increased efficacy in refractory epilepsy and for antiepileptogenesis.