Emerging Growth of Orphan Drugs for Neurological Diseases in Japan: Potential Benefits for Both Patients and Pharmaceutical Companies

Abstract

Despite the existence of numerous rare neurological diseases, no studies have been conducted on orphan drugs for neurological diseases available on the Japanese pharmaceutical market and their potential benefits. In this context, from a statistical perspective, we investigated 1) the market position of orphan drugs in Japan, and 2) the market penetration of generic medicines. To the best of our knowledge, this is the first empirical study to examine the current status and development strategy of orphan drugs approved for neurological diseases in the Japanese pharmaceutical market. The perspectives provided by this research are expected to promote the clinical development of orphan drugs in Japan for patients suffering from intractable neurological diseases that currently have no known effective therapies. The dataset used in this research was generated from publicly and commercially available data sources in Japan. Marketing approvals for orphan neurological products have increased dramatically in recent years. As much as 10% of all drugs approved for neurological diseases in Japan were orphan drugs that met urgent medical needs. Six of these orphan drugs were ranked in top 500 best-selling drugs in Japan, which indicated the presence of a potentially large market. Compared with more conventional drugs, the prices of orphan drugs are not expected to be reduced. In addition, due to an apparent lack of competition from generics, the quantity of available orphan drugs has remained steady, suggesting stable long-term sales. Most orphan drugs in Japan have adopted innovative marketing strategies that divide major neurological diseases into a more specific variety of rare disease categories. We found that orphan drugs approved for neurological diseases in Japan have been launched steadily. It is unlikely that these drugs will be affected by regular price revisions and the launch of their generic counterparts. Based on these findings, the further development of orphan drugs in Japan should be encouraged in order to meet urgent medical needs and deliver innovative drugs to patients suffering from rare neurological diseases.