A Special Protocol Assessment (SPA) is an advanced declaration from the Food and Drug Administration that an uncompleted Phase III trial's design, clinical endpoints, and statistical analyses are acceptable for FDA approval. The purpose of a SPA is to allow a company to run or initiate a clinical trial of an experimental drug without fear that the FDA will object to the trial design itself, in the event that the company subsequently applies for product approval.
Three types of protocols related to PDUFA products are eligible for this special protocol assessment under the PDUFA goals:
animal carcinogenicity protocols,
final product stability protocols,
clinical protocols for phase 3 trials whose data will form the primary basis for an efficacy claim if the trials had been the subject of discussion at an end-of-phase 2/pre-phase 3 meeting with the review division, or in some cases, if the division agrees to such a review because the division is aware of the developmental context in which the protocol is being reviewed and the questions are being answered.
The clinical protocols for phase 3 trials can relate to efficacy claims that will be part of an original new drug application (NDA) or Biologic License Application (BLA) or that will be part of an efficacy supplement to an approved NDA or BLA.