21 CFR 314.510 : Food And Drugs (§ 1.1 To Parts 1403-1499) — (Subpart A To Parts 370-499) — Food And Drug Administration, Department Of Health And Human Services (Continued) (Subpart A To Parts 370-499) — Drugs For Human Use (Subpart A To Parts 370-499) — Applications For Fda Approval To Market A New Drug (§ 314.1 To § 314.650) — Accelerated Approval Of New Drugs For Serious Or Life-Threatening Illnesses (§ 314.500 To § 314.560) — Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival or irreversible morbidity.

FDA may grant marketing approval for a new drug product on the basis of adequate and well-controlled clinical trials establishing that the drug product has an effect on a surrogate endpoint that is reasonably likely, based on epidemiologic, therapeutic, pathophysiologic, or other evidence, to predict clinical benefit or on the basis of an effect on a clinical endpoint other than survival or irreversible morbidity. Approval under this section will be subject to the requirement that the applicant study the drug further, to verify and describe its clinical benefit, where there is uncertainty as to the relation of the surrogate endpoint to clinical benefit, or of the observed clinical benefit to ultimate outcome. Postmarketing studies would usually be studies already underway. When required to be conducted, such studies must also be adequate and well-controlled. The applicant shall carry out any such studies with due diligence.