Priority review


Priority review is a program of the United States Food and Drug Administration to expedite the review process for drugs that are expected to have a particularly great impact on the treatment of a disease. The priority review voucher program is a program that grants a voucher for priority review to a drug developer as an incentive to develop treatments for disease indications with limited profitability.
Priority review vouchers are currently earned by pharmaceutical companies for the development and approval of drugs treating neglected tropical diseases, rare pediatric diseases, and "medical countermeasures" for terrorism. The voucher can be used for future drugs that could have wider indications for use, but the company is required to pay a fee to use the voucher.
When seeking approval for a drug, manufacturers can apply to the FDA for priority review. This is granted when a drug is intended to treat a serious condition and would "provide a significant improvement in safety or effectiveness" over currently available treatments. A priority review voucher can be used when a drug does not fit these requirements, but the company wishes to expedite the review process.
In 2007, Title XI of the Food and Drug Administration Amendments Act of 2007 created the priority review voucher program for neglected tropical diseases. This was extended in 2012 by the Food and Drug Administration Safety and Innovation Act to include rare pediatric diseases. The act built upon the tropical disease system and made amendments including a shorter notification to the FDA before exercising a voucher, a designation system so that early in the drug development cycle sponsors may use the possibility of earning a voucher in their valuation of their company, a requirement of a marketing plan and reporting of marketing, and indefinite transferability of the voucher. In 2016, medical countermeasures were added to the program.

Priority review

Prior to approval, each drug marketed in the United States must go through a detailed FDA review process. In 1992, under the Prescription Drug User Fee Act, FDA agreed to specific goals for improving the drug review time and created a two-tiered system of review times – standard review and priority review.
A priority review designation is given to drugs that offer major advances in treatment, or provide a treatment where no adequate therapy exists. The 2002 amendments to PDUFA set a goal that a standard review of a new drug application be accomplished within a ten-month time frame. The FDA goal for completing a priority review is six months. Priority review status can apply both to drugs that are used to treat serious diseases and to drugs for less serious illnesses.
The distinction between priority and standard review times is that additional FDA attention and resources will be directed to drugs that have the potential to provide significant advances in treatment. Such advances can be demonstrated by, for example:
evidence of increased effectiveness in treatment, prevention, or diagnosis of disease; elimination or substantial reduction of a treatment-limiting drug reaction; documented enhancement of patient willingness or ability to take the drug according to the required schedule and dose; or evidence of safety and effectiveness in a new subpopulation, such as children.
A request for Priority Review must be made by the drug company. It does not affect the length of the clinical trial period. FDA determines within 45 days of the drug company's request whether a priority or standard review designation will be assigned. Designation of a drug as "priority" does not alter the scientific/medical standard for approval or the quality of evidence necessary. Safety requirements for a priority review are equal to that of a standard review.
The amendment can be found on page 150 of the Food and Drug Administration Amendments Act of 2007.

Priority review voucher program

The statute authorizes the FDA to award a priority review voucher to the sponsor of a newly approved drug or biologic that targets a neglected tropical disease or a rare pediatric disease. The provision applies to New Drug Applications, Biological License Applications and 505 applications. The voucher, which is transferable and can be sold, entitles the bearer to a priority review for another product.
Under current Prescription Drug User Fee Act targets, the FDA aims to complete and act upon reviews of priority drugs within six months instead of the standard ten-month review period. Actual FDA review timelines, however, can be longer than the target PDUFA review periods, particularly for new products that haven't previously been approved for any indications. Economists at Duke University, who published on this concept in 2006, estimated that priority review can cut the FDA review process from an average of 18 months down to six months, shortening by as much as a full year the time it takes for the company's drug to reach the market.
An intangible benefit of the voucher is the value created for a company if the faster review provides them "first mover advantage," allowing the voucher holder's product to be introduced ahead of a similar, competing product. By taking advantage of existing market forces, patients in the developing world can have faster access to lifesaving products that may not otherwise be developed. And sponsors of neglected disease drugs can be rewarded for their innovations
Sponsors must inform the FDA of their intention to use a priority review voucher 90 days before submission. Before the Adding Ebola to the FDA Priority Review Voucher Program Act in 2014, this requirement was 365 days, which was a hindrance to the process of speedy review, as companies do not typically determine when drugs will be submitted until the results of safety studies are available.
Companies may also sell vouchers to other drug companies. Thus far, priority review vouchers have sold for $50–350 million.

Cost

Companies that use the voucher will be required to pay a supplemental priority review user fee to ensure that the FDA can recoup the costs incurred by the agency for the faster review, in addition to the fee for standard review of drugs. The additional user fee also aims to ensure that the new program will not slow the progress of other products awaiting FDA review. The cost has decreased dramatically from over $5 million in 2012. For the fiscal year 2018, this fee is $2.8 million.

Uses of the priority review program

, fourteen priority review vouchers have been awarded, four for tropical diseases, and ten for rare pediatric diseases. The first priority review voucher was awarded in 2009 to Novartis for its approval of Coartem. The next voucher was not awarded until 2012.
ProgramDrugIndicationCompanyYear
Tropical diseaseCoartemMalariaNovartis
Tropical diseaseSirturoMulti-drug-resistant tuberculosisJanssen Pharmaceutica
Rare pediatric diseaseVimizimMorquio syndromeBioMarin Pharmaceutical
Tropical diseaseImpavidoLeishmaniasisKnight Therapeutics
Rare pediatricUnituxinNeuroblastomaUnited Therapeutics
Rare pediatricCholbamZellweger syndromeAsklepion Pharmaceuticals
Rare pediatricXuridenOrotic aciduriaWellstat Therapeutics
Rare pediatricStrensiqHypophosphatasiaAlexion Pharmaceuticals
Rare pediatricKanumaLysosomal acid lipase deficiencyAlexion
Tropical diseaseVaxchoraCholera preventionPaxVax
Rare pediatricExondys 51Duchenne muscular dystrophySarepta Therapeutics
Rare pediatricSpinrazaSpinal muscular atrophyIonis Pharmaceuticals
Rare pediatricEmflazaDuchenne muscular dystrophyMarathon Pharmaceuticals
Rare pediatricBrineuraBatten diseaseBioMarin Pharmaceutical
Tropical diseasebenznidazoleChagas diseaseChemoResearch
Rare pediatricKymriahB-ALLNovartis
Rare pediatricMepseviiMucopolysaccharidosis type VIIUltragenyx
Rare pediatricLuxturnaRPE65-mutated retinal dystrophySpark Therapeutics
Rare pediatricCrysvitaX-linked hypophosphatemiaUltragenyx2020
Tropical diseaseMoxidectinOnchocerciasisMedicines Development for Global Health
Rare pediatricEpidiolexLennox–Gastaut syndromeGW Pharmaceuticals
Material threat countermeasureTpoxxSmallpoxSIGA Technologies
Tropical diseaseKrintafelMalariaGlaxoSmithKline
Rare pediatricRevcoviAdenosine deaminase-SCIDLeadiant Biosciences
Rare pediatricGamifantHaemophagocytic lymphohistiocytosisNovimmune
Tropical diseaseEgatenFascioliasisNovartis
Rare pediatricSymdekoF508del cystic fibrosisVertex Pharmaceuticals
Tropical diseaseDengvaxiaDengueSanofi
Rare pediatricZolgensmaSpinal muscular atrophyAveXis
Tropical diseasePretomanidTuberculosisTB Alliance
Material threat countermeasureJynneosSmallpoxBavarian Nordic
Rare pediatricTrikaftaCystic fibrosisVertex Pharmaceuticals
Tropical diseaseErveboEbolaMerck & Co.
CapmatinibMET exon 14 skipping mutated non-small cell lung cancerNovartis
KTE-X19Mantle cell lymphomaKite Pharma
SelpercatinibRET fusion-positive non-small cell lung cancerEli Lilly
elantamab mafodotinMultiple myelomaGlaxoSmithKline
Cedazuridine and decitabineChronic myelomonocytic leukemiaAstex Pharmaceuticals
Rare pediatricVyondys 53Duchenne muscular dystrophySarepta Therapeutics2020
Rare pediatricOxlumoPrimary hyperoxaluria type 1Alnylam Pharmaceuticals2020
Rare pediatricRethymicCongenital athymiaEnzyvant Therapeutics2021