Before approval, each drug marketed in the United States must go through a detailed FDA review process. Priority Review is where the Agency aims to take action within six months of filing, instead of the 10 months it takes under Standard Review. During 2022, 57% of the novel drugs approved were designated Priority Review.

The FDA offers different approaches to shorten the drug approval process. In 1992, under the Prescription Drug User Act (PDUFA), FDA agreed to specific goals for improving the drug review time and created a two-tiered system – Standard Review and Priority Review. FDA classifies all original NDAs, original BLAs, and efficacy supplements for either priority or standard review. However, an applicant may request priority review in the application. Unlike the other expediated pathways, Priority Review involves no discussions of study design or procedure; the primary benefit is a review time reduction, and that FDA intends to direct overall attention and resources to the evaluation of these applications.

Unlike Fast Track or Accelerated Approval, the Priority Review process begins only when the company officially submits an NDA/BLA or efficacy supplement. Priority Review, therefore, does not alter the timing or content developed prior to the submission.

As part of the FDA, The Center for Drug Evaluation and Research (CDER) determines whether the drug treats a serious condition and, if approved, would provide a significant improvement in safety or effectiveness of the treatment, diagnosis, or prevention of serious conditions. If yes, the drug receives a Priority Review designation. All original NDAs and efficacy supplements that do not meet the criteria for Priority Review receive the Standard Review designation.

An application for Priority Review should be submitted with the original BLA, NDA, or efficacy supplement, and the agency will usually respond within 60 calendar days of receiving the original filing. 

Qualifying Criteria:

• An application (original or efficacy supplement) for a drug that treats a serious condition AND, if approved, would provide a significant improvement in safety or effectiveness OR
• Any supplement that proposes a labelling change in accordance with pursuant to a report on a paediatric study under 505Ab OR
• An application for a drug that has been designated as a qualified infectious disease product OR
• Any application or supplement for a drug submitted with a priority review voucher.

The Priority Review vouchers are incentives meant to spur the development of new treatments for diseases that would otherwise not attract development interest from companies due to the cost of development and the lack of market opportunities. The voucher is linked to the company and not the product per se and allows the developer/manufacturer to expedite the review of any one of its new drug products. There are three voucher programs so far; neglected tropical disease priority review voucher system, rare paediatric disease priority review voucher, and medical countermeasure priority review vouchers.

Priority Review can be received in addition to having Fast Track or Breakthrough Therapy designations, as long as the product is believed to address unmet needs, and the relevant criteria are met. FDA determines case-by-case whether a proposed drug would improve safety or effectiveness in the treatment, prevention, or diagnosis of a serious condition when an NDA, BLA, or efficacy supplement is filed. Significant safety improvement may be demonstrated by the following examples:

• Evidence of increased effectiveness in treatment, prevention, or diagnosis of the condition.
• Elimination or substantial reduction of a treatment-limiting drug reaction.
• Documented enhancement of patient compliance that is expected to lead to an improvement in serious outcomes. 
• Evidence of safety and effectiveness in a new subpopulation.

Clinical trials comparing the investigational drug with products already on the market can provide evidence for Priority Review designation, but other scientifically valid information can also be considered. Generally, if there is an available therapy, the developer should compare their investigational drug to the available therapy in clinical testing with an attempt to show superiority relating to either safety or effectiveness. Alternatively, they could show the drug’s ability to effectively treat patients who are unresponsive to or unable to tolerate available therapy.

Although FDA expects the source of this evidence to be a comparison between the new drug product and a currently available therapy, FDA has some flexibility in the types of evidence that will establish a significant improvement. Usually, such findings are based on randomized trials, but historical controls could also be influential.

FDA classifies marketing application submissions and efficacy supplements for either standard or priority review. To qualify for priority review, the new drug should provide a significant improvement in safety or effectiveness of the treatment, diagnosis, or prevention of serious conditions. This type of expedited approval focuses on the evaluation of the drugs and does not alter the timing or content developed prior to the submission.

Our presence in the US is growing! NDA can offer strategic insights as well as the regulators perspective to your product development and your interactions with FDA.