As part of the PDUFA V reauthorization discussions, the FDA and industry are talking about better approaches to rare disease drug development and orphan drugs. Public interests and Congress have mandated that the FDA develop new guidances on the required studies needed for NDA approval. In these discussions, participants refer to the “pediatric drug development approach” as a model. What are they talking about?

The discussions were made at a March 2, 2011, session of the Advisory Committee for Pharmaceutical Science and Clinical Pharmacology in conjunction with the annual meeting of the American Society for Clinical Pharmacology and Therapeutics. The FDA presentation stated that the pediatric model is “Using data from adult subjects to define metabolism, dose response, drug interactions and allowing us to focus on the pediatric aspects.”

If this sounds a lot like the 505(b)(2) approach, you’re correct. In fact, both the FDA and advisory committee members discussed “re-purposing” which the FDA defined as:

“…. the development of an already approved drug for use in an orphan indication.

• The use of knowledge of related disease/drug mechanisms to identify potential drug candidates at any stage of development
• Generally allows the fastest route for a drug as the initial mass-balance, animal safety, drug interaction, and special population work is already done.
• Development program is targeted to the orphan populations’ needs in terms of dose and any potential intrinsic factors that may affect drug disposition.”

Thus, the Advisory Committee and FDA agreed that orphan drugs used to treat rare diseases can be developed using principles established that have been used for re-purposing (505(b)(2) and pediatric drug development based on drugs studied in adult populations.