Zach Brennen at Regulatory Focus: The FDA’s PRV Program Is at a Legislative Juncture
This is a MUST READ from Zachary Brennen at RAPS/Regulatory Focus on the review and potential reauthorization of the controversial priority review voucher (PRV) program of the FDA.
Notably 2 bipartisan bills are circulating to reauthorize the program. One of these would expand the pediatric PRV program to include childhood cancers and sickle cell anemia. But this particular bill would also,
“…amend the rare tropical PRV program to contain ‘an assurance (satisfactory to the Secretary) that the drug for which the application is submitted has not been approved for commercial marketing for any tropical disease indication by a government authority outside of the United States for more than 24 months before the application is submitted.'”
This amendment is important because of (what I would call) one abuse of the intent of the PRV program: Namely, the FDA approval of long-existing antimicrobials—eg, miltefosine (Knight Therapeutics) for leshmaniasis and possibly benznidazole (Savant/Kalobios) for Chagas disease—on the basis of little R&D investment by the US-rights-holding applicant company.
Generally the FDA does not like the PRV programs, Brennen notes, chiefly because PRVs* are being used to priority review NDAs that really don’t deserve priority reviews. Brennan quotes FDA spokesperson Deborah Kotz:
“In effect, these programs allow sponsors to ‘purchase’ a priority review at the expense of other important public health work in FDA’s portfolio. The FDA has very limited resources and the more we are mandated to provide special attention to products that do not warrant such special attention, the less any application can be treated as a priority…The special user fee for redemption of a PRV, while calculated to compensate the FDA for the extra work involved in conducting a priority review on a standard application, does not in practice provide additional review resources to the team responsible for reviewing the application that is the subject of the redeemed voucher.
Questions have been circulating on Twitter as to what might happen to Sarepta’s PRV (which was recently bestowed by the FDA for its accelerated approval of eteplirsen for Duchenne muscular dystrophy), IF eteplirsen does not prevail in an FDA-mandated follow-up clinical trial. According to Brennen, who seems to be the only reporter who has been able to answer this question, the FDA would not revoke or withhold the PRV under those circumstances.