Characteristics of Anticancer Drugs Approved Under the Accelerated Approval Program in the US: Success or Failure in Converting to Regular Approval.

ABSTRACT

BACKGROUND: Accelerated approval (AA) program expedites access to promising drugs for life-threatening conditions, particularly in oncology. However, challenges arise from the trade-off between faster access and the certainty of clinical benefits. We examined the differences between the indications for successful conversion of AA to regular approval (RA) and those withdrawn from the perspective of whether the confirmatory trial was appropriately designed and conducted to verify the efficacy estimated in the pivotal trial for AA (AA trial). METHODS: All the anticancer drugs approved by the United States (US) Food and Drug Administration (FDA) between January 2016 and December 2019 were identified on the FDA website. From these, we selected drugs granted AA for solid tumors based on single-arm trials. We compared the characteristics of the AA and confirmatory trials between products that were successfully converted to RA and those that were withdrawn. RESULTS: Twenty-four AA indications were identified, of which 11 were converted to RA and 6 were withdrawn. The magnitude of the objective response rate (ORR) in both the AA and confirmatory trials was not a factor that clearly determined the conversion or withdrawal of AA. However, if the experimental arm did not achieve a certain level of ORR over the control arm in the confirmatory trial, it was thought to increase the uncertainty of successful conversion to RA. CONCLUSION: A relatively high ORR compared with that of the control arm in the confirmatory trial, after AA, is important for successfully obtaining RA.