A study led by Dr. Ariadna Tibau, researcher at the Sant Pau Research Institute (IR Sant Pau) and oncologist at Hospital de Sant Pau, was recently published in the journal JAMA Network Open. The article systematically analyzes for the first time which factors contribute to a faster transition from accelerated to regular approval of oncology drugs by the U.S. Food and Drug Administration (FDA). The study also included participation from Alejandra Romano, oncology resident at Hospital Sant Pau, and Dr. Ignasi Gich, researcher with the Clinical Epidemiology and Health Services Group at IR Sant Pau.
The FDA’s accelerated approval pathway, in place since 1992, allows new drugs for serious conditions to reach patients more quickly. This route is based on preliminary results using surrogate clinical endpoints, but continued approval of these drugs is contingent on follow-up confirmatory trials demonstrating their efficacy and safety.
This international, retrospective study evaluated 102 indications for oncology drugs that received accelerated approval between 1992 and 2022 and subsequently gained full FDA approval before August 31, 2024. The findings show that conversion to full approval occurs more rapidly when certain characteristics are present at the time of initial approval: priority review designation, absence of serious safety warnings, initiation of confirmatory trials before approval, and an intermediate or high clinical benefit based on the ESMO-Magnitude of Clinical Benefit Scale (ESMO-MCBS).
“Our analysis shows that drugs with greater therapeutic potential and no major safety concerns at the time of accelerated approval tend to complete confirmatory trials more quickly and receive full approval sooner,” explains Dr. Ariadna Tibau. “This information can be very useful for regulators and clinicians, as it helps anticipate which drugs are more likely to demonstrate real benefit for patients.”
The study also highlights that among the confirmatory trials analyzed, those that showed a significant benefit in overall survival or quality of life were completed in less time. In contrast, drugs with less clear results took significantly longer to achieve full approval, which may expose patients to treatments of uncertain value over extended periods.
One of the key contributions of this work is the use of the ESMO-MCBS scale to assess the clinical benefit of drugs. According to Dr. Tibau, “It is essential that approval mechanisms be accompanied by tools that help prioritize therapies with the highest real clinical value. In this regard, the ESMO-MCBS can support more informed decision-making both in regulatory settings and clinical practice.”
The study was conducted in collaboration with leading research centers such as Harvard Medical School, Brigham and Women’s Hospital, Dana-Farber Cancer Institute, the Vall d’Hebron Institute of Oncology (VHIO), Queen’s University (Canada), and the Clinical Epidemiology team at Hospital de Sant Pau. The work was supported by the Kaiser Permanente Institute for Health Policy, with grants from Arnold Ventures, The Commonwealth Fund (for Dr. Kesselheim), and the Alfonso Martín Escudero Foundation (for Dr. Tibau).
Tibau A, Hwang TJ, Romano A, Borrell M, Gich I, Molto C, Kesselheim AS. Factors in time to full approval or withdrawal for anticancer medicines granted accelerated approval by the FDA. JAMA Netw Open. 2025;8:e252026. https://doi.org/10.1001/jamanetworkopen.2025.2026
