Introduction and Background
The Accelerated Approval (AA) program is a drug development pathway that was established to expedite the delivery of promising treatments to patients, primarily for serious and life-threatening conditions. AA is granted based on surrogate endpoints, such as tumor size reduction in cancer patients, that are reasonably likely to predict clinical benefit. These endpoints can be measured earlier than traditional endpoints, such as overall survival. Drugs granted AA are required to complete a confirmatory trial to further assess their clinical benefit. There are two possible outcomes for drugs granted AA: (i) the confirmatory trial “verifies” benefit, and the drug is granted full approval, (ii) the confirmatory trial fails to confirm benefit, and the drug is withdrawn from market. Drugs are considered “ongoing” while their confirmatory trials are still in progress.
To assess the efficiency and impact of AA over time, we analyzed publicly available data on the 344 AAs granted from June 1992 to December 2024 identifying trends in approvals, postmarket actions, and the timelines for confirmatory trials.
Trends in AA Utilization
The number of approvals through the AA program has increased over time, with notable shifts in the types of drugs receiving AA. In 2013, there was a substantial increase in AAs indicated for cancers/hematologic malignancies. This shift was likely driven by several factors, including advances in targeted therapies, increased availability and acceptance of surrogate endpoints (e.g., response rate and progression-free survival), and growing regulatory familiarity with AA. More recently, the program has supported an increasing number of approvals for vaccines to treat infectious diseases and drugs for non-malignant hematological, neurological, and other disorder(s) (Figure 1).
Figure 1: Accelerated Approvals Over Time by Indication, 1992-2024
What Happens After AA?
To evaluate the postmarket trajectory of AA drugs, we analyzed the breakdown of AA drugs by status (withdrawn, verified, or ongoing). It is important to note that not all 344 AAs analyzed were first-time approvals; this total includes both original approvals and supplemental indications granted AA. In other words, we evaluated all indication-drug pairs granted AA, as a single drug may receive AA for multiple indications.
Across all indication categories, we found that more than half of AAs (54%, 189/344) were converted to full approval, indicating the program successfully supports confirmation of benefit and transition to full approval in most cases. A smaller proportion of AAs (13%, 45/344) were withdrawn (Figure 2). The relatively low rate of withdrawn AAs underscores the importance of timely confirmatory evidence and efficient processes to ensure that drugs failing to demonstrate benefit do not remain on the market.
Currently, 32% (110/344) of AAs are still classified as “ongoing,” actively advancing through the accelerated approval process (e.g., completing confirmatory trials or awaiting FDA review and determination of confirmatory evidence). Importantly, over half of these drugs (55.5%, 61/110) were granted AA within the last four years, and the majority (79%, 87/110) were granted AA within the last five years. This distinction suggests that most ongoing AAs are progressing through confirmatory trials within expected timelines rather than remaining on the market for an extended period without action.
Figure 2. Number of Approvals by Status & Indication Category
Timeliness of Postmarket Actions
Recognizing the importance of timely confirmatory trials to inform postmarket decision-making, we evaluated the median time to either withdrawal or full approval. Verification of benefit supporting conversion to full approval occurs within four years of AA for all indication categories. For oncology drugs, withdrawal occurs at a median of 3.8 years. However, this level of efficiency is not reflected across all indication categories, and extended withdrawal times in some indication categories warrant further examination to identify challenges to timely completion of confirmatory trials (Figure 3). This may help to optimize AA processes, explore alternative approaches to evidence generation, or identify where flexibility is appropriate.
One key challenge relates to enrolling participants in confirmatory trials, particularly for non-cancer AAs intended to treat rare diseases with small patient populations. Once a drug is approved and available outside of clinical trials, recruitment for confirmatory trials can become difficult. Recent policy changes and regulatory guidance provide recommendations clarifying that confirmatory trials should be underway (e.g., fully enrolled) at the time of approval to help mitigate such delays.
The difference in withdrawal timelines between AAs for oncology versus non-oncology indications may also be attributed to the extensive experience in using AA for oncology indications, supporting best practices for efficient confirmatory trial planning and execution.
Figure 3. Median Years to Action for Withdrawn and Verified AAs
Improvements Over Time
Despite delayed withdrawal timelines in some instances, there has been notable progress toward timelier postmarket actions. We evaluated whether timelines for withdrawal, verification of benefit, or estimated time to complete the PMR have improved over time. We found that, over time, the median time to AA verification (and conversion to full approval) and time to withdrawal have both decreased. Additionally, for the ongoing AAs, the estimated time to complete confirmatory trial PMRs (years from AA to projected PMR completion) has steadily decreased in recent years (Figure 4). These improvements suggest that scientific advancements, policy refinements, and regulatory learnings have contributed to a more efficient and predictable AA process.
Figure 4. Years to Postmarket Action* & Estimated Action* Over Time
*Note: For Withdrawn and Verified Approvals, the lines show the median time from the AA Date to the Date of Withdrawal or Date of Full Approval; For Ongoing Approvals line shows median time to PMR Due Date calculated as Years from the AA Date to the Projected PMR Completion Date reported at the time of AA.
The Importance of Ongoing Optimization
Our findings reaffirm that the AA program remains a critical tool for expediting access to promising drugs in areas of unmet clinical need. The majority of AAs ultimately receive full approval, with verification of benefit occurring in a timely manner (median of <4 years) for most drugs. Since the program’s inception, scientific progress, regulatory guidance, policy refinements have helped optimize its use and expand its impact across more disease areas with high unmet need. As the AA program continues to evolve, continued efforts to improve confirmatory trial timelines, enhance regulatory clarity, and ensure efficient postmarket actions will be essential to maintaining its success.
These findings highlight the importance of continued efforts and guidance in optimizing the AA program, ensuring it remains a robust regulatory mechanism for delivering innovative treatments while upholding scientific rigor and patient safety.
In 2020, Friends released a White Paper “Optimizing the Use of Accelerated Approval”, highlighting the AA program’s critical role in delivering promising treatments to patients — particularly for serious and life-threatening conditions—while maintaining scientific rigor. The paper also proposed key program. Congress echoed these priorities in the Consolidated Appropriations Act of 2023, which recognized the importance and need for continued optimization of AA to ensure it remains a reliable and responsive regulatory tool. As drug development advances and promising therapies emerge, ongoing refinements to the AA program will be crucial to maintaining a balance between innovation, patient access, and regulatory oversight.
Thank you to Authors:
Karina Bhavsar recently graduated from the University of San Francisco and was an undergraduate intern at Friends of Cancer Research in 2025.
Grace Collins serves as Manager, Regulatory & Data Insights at Friends of Cancer Research.
