As with other incentive programs, FDA created the Rare Pediatric Disease (RPD) designation to encourage drug development in products with questionable financial viability; in this case, the treatment of certain rare pediatric diseases.  One of the main benefits of RPD designation is the potential to receive priority review vouchers, which can be used to obtain priority review on a subsequent human drug or biologic application, should the product with RPD designation be approved.  Priority review vouchers have few restrictions, and can be used by the sponsor or sold/transferred to a separate organization.  In some cases, priority review vouchers have sold for over $100 million.

While the potential financial benefits of RPD designation are compelling, the program, as mandated by the 21^st Century Cures Act, has limited availability.  As things currently stand, FDA is sunsetting the program, and may not award priority review vouchers for any product unless the product has received RPD designation by September 30, 2020.  Therefore, as of the time of this article, pharmaceutical companies have approximately 5 months to receive the designation from the Office of Orphan Products Development (OOPD) at FDA.  FDA does have a review clock on such an application, but only under specific circumstances.  Section 529(d)(2) provides that a sponsor shall submit a request for RPD designation at the same time that they submit either an orphan drug application or a fast track designation; FDA has interpreted “at the same time” to mean within 2 weeks.  If a timely submission occurs, then section 529(d)(3) directs FDA to make a decision on the request no later than 60 days after the submission.  Note that, if the application is submitted in a timely fashion, information in an orphan drug application can be cross-referenced rather than transferred into the RPD application itself.  If submitted outside of a request for orphan drug or fast track designation, then FDA is under no time frame for review.

How can a sponsor increase the chances of a favorable first round review?  The first step is to ensure that the proposed indication meets the requirements for orphan designation, as the RPD application itself requests very similar information.  Second, we recommend that sponsors include data from the literature to support the early and serious effects of the disease in children.  Seriousness of the disease in childhood is critical to approval, and providing solid evidence from the literature or other data sources to substantiate this claim is the most important element that is needed for the RPD designation request beyond what one would provide for an orphan designation request.  Based on our previous experience, this means showcasing to the OOPD that greater than greater than 50% of the affected population in the US is between birth and 18 years of age.  This can generally be achieved by summarizing prevalence of serious symptoms by age.

Finally, even if a sponsor’s product receives RPD designation, the guidance notes that, after September 30, 2022, FDA may not award any RPD priority review vouchers.  While this may cause some sponsors to hesitate, especially if their product is early in development, we note that legislative extensions can occur, and therefore seeking RPD designation may still be valuable.

In any case, Rho can help your company move forward with a timely RPD submission.  Please contact our business development group if you have any questions.

Joseph Watson, PhD, RAC, Research Scientist at Rho, has experience in both regulatory submissions and clinical document preparation, with over fifteen years of experience in scientific writing and editing clinical and nonclinical documents, including numerous publications in peer-reviewed journals.  Dr. Watson has led the preparation, review, and coordination of a variety of regulatory and clinical documents, including protocols; clinical study reports; integrated summaries of biopharmaceutics, safety, and efficacy; CMC and nonclinical documents; draft product labels; and 120‑day safety updates.  His writing and editing experience covers a broad range of therapeutic areas, including drug addiction, middle ear disorders, infectious diseases, psychiatric disorders, acute and chronic pain, multiple sclerosis, hemophilia, and oncology.