Pediatric Priority Review Vouchers: A Subtle Upgrade to Renewal Plans

By Alexander J. Varond –

On July 10, 2015, the U.S. House of Representatives passed the 21st Century Cures Act.  In all, there were 344 “yes” votes and only 77 “no” votes, with half of the “yes” votes coming from Republicans and the other half coming from Democrats.  We have blogged on the 21st Century Cures Act here and here.  In addition, the House has provided a two-page summary and a section-by-section summary of the current legislation.

Although the overall 21st Century Cures Act is not the topic of this blog post, we give its passage in the House prominence here because it includes the most developed proposal for the renewal of FDA’s rare pediatric disease priority review voucher program (Pediatric PRV program).  We have blogged extensively on the Pediatric PRV program, including here and here.  Without congressional action, FDA will be unable to grant Pediatric PRVs after mid-March 2016 (see our post on the program’s sunset here).

Recall that the Pediatric PRV program was developed as a means to encourage the development of therapies to treat rare diseases that primarily affect children.  Since the program’s inception in 2012, three sponsors have received Pediatric PRVs.  Pediatric PRVs have been issued for: 

1. Vimizim (elosulfase alfa) for mucopolysaccharidosis type IVA (a rare, severely debilitating and progressive disease);
2. Unituxin (dinutuximab) for high-risk neuroblastoma (a rare pediatric cancer); and
3. Cholbam (cholic acid) for bile acid synthesis disorders due to single enzyme defects and for peroxisomal disorders (including Zellweger spectrum disorders) (both inborn errors of metabolism).

(See our posts on each of these grants here, here, and here.)

Industry has taken considerable interest in the Pediatric PRV program.  After all, the most recent priority review voucher sold for an incredible $245 million dollars.  Here is a rundown of the publicly announced sales of priority review vouchers to date: 

Table 1: PRV Sales Data

Despite significant interest in the Pediatric PRV program, thereis concern related to the program’s unpredictable availability.  Stated another way, companies do not know whether the Pediatric PRV program will be reauthorized or how long it will be authorized for.  This uncertainty has had a considerable chilling effect.

A Change in the Proposed Legislation.  The most recent version of the 21st Century Cures Act pegs the sunset of the program to the date on which a sponsor files its marketing application (so long as the drug is also designated as a drug for a rare pediatric disease prior to the sunset date).  In the past, a sponsor’s marketing application had to be approved by the sunset date.  This small change is significant—it creates more certainty because it does not subject sponsors’ eligibility to unpredictable delays in the review process.

Below, we catalogue the current law and recent proposals for reauthorizing the program.

Table 2:  Pediatric PRV Sunset Provisions (Current Law and Recent Proposals)

A Proposal for a Different Sunset Date.  Short of significantly increasing the duration of the program or making it permanent, it would be helpful if future legislation used a different sunset date.  As the status quo demonstrates, timing on the reauthorization of the program is unpredictable and unpredictability can be costly.  Therefore, instead of designating an arbitrary sunset date (e.g., December 31, 2018), the sunset date of the Pediatric PRV program could be tied to the sunset date of the Prescription Drug User Fee Act (PDUFA) authorization (e.g., September 30, 2022).  

By tying the sunset of the Pediatric PRV program to the sunset date of PDUFA authorization, the Pediatric PRV program would have a predictable platform on which it could be reauthorized.  With the predictable timing of PDUFA reauthorization, the timing of the Pediatric PRV program’s reauthorization would also be more predictable.  As a result, sponsors could plan better and invest more in developing the therapies that the program intends to encourage—therapies for rare pediatric diseases.