Ever heard of Hailey-Hailey Disease? How about factor V deficiency or Hemimegalencephaly? These are a few examples of rare diseases, e.g., those afflicting fewer than 200,000 Americans.

Rare diseases have long had trouble attracting research funding to develop pharmaceutical treatments. One program created by the 1983 Orphan Drug Act incentivizes drug companies to research potential new drugs, or novel uses of existing drugs, to treat rare diseases. Companies apply for orphan drug status from the Food and Drug Administration (FDA). If approved, the companies receive a fee waiver, tax credits, and if they later show their drug is safe and effective against a rare disease, the main prize: seven years of market exclusivity – a period wherein no competitors can sell the same drug.

The orphan drug program is not new, but rising popularity of the program in recent years has led to a backlog of applications. Late last month, the FDA announced an initiative to clear the backlog and speed up the approval process for orphan drug designations. In the next 90 days, FDA’s Office of Orphan Products Development hopes to complete its review of all orphan drug designation requests that are more than 120 days old. Afterward, it will aim to respond to all new requests for orphan status within 90 days.

The FDA’s intent is to increase the pace of research and development for ailments that might otherwise be overlooked. However, critics have argued some manufacturers of mass market drugs are taking advantage of the program. A Kaiser Health News analysis found 7 out of the 10 best-selling drugs in the country have been granted orphan drug status for alternate uses to treat rare diseases. This is currently legal, though, as there is no prohibition on a popular drug receiving orphan status or even on a single drug receiving multiple orphan designations.

More information about the Orphan Drug Designation Program is available at the FDA Office of Orphan Products Development’s website.