FDA accelerated approval is one of the agency’s most powerful and most debated regulatory tools. Designed to speed access to treatments for patients with serious or life-threatening conditions, it has delivered transformative therapies to those with no other options. It has also drawn sustained scrutiny over drugs that remained on the market long after their promised confirmatory evidence failed to materialise. Understanding how the pathway works, what it demands of drug developers, and how it is being reformed is increasingly essential for anyone navigating pharma, biotech, or clinical research.
What Is FDA Accelerated Approval?
The FDA accelerated approval pathway was established in 1992 as a direct response to the HIV/AIDS epidemic, when the urgent need for new treatments collided with the lengthy timelines of conventional drug development. Codified in statute by Congress in 2012, it allows the FDA to grant market authorisation based on a surrogate or intermediate clinical endpoint, rather than waiting for direct evidence of clinical benefit such as improved overall survival.
A surrogate endpoint is a measurable marker, typically a biomarker, laboratory measurement, radiographic image, or physical sign, that is considered reasonably likely to predict a clinical benefit but has not itself been shown to directly improve how patients feel, function, or survive. In oncology, surrogate endpoints have commonly included objective response rate, the proportion of patients whose tumours shrink, and progression-free survival, the length of time before disease worsens. In Alzheimer’s disease, the reduction of amyloid plaques in the brain served as the surrogate basis for the accelerated approval of lecanemab, marketed as Leqembi, by Eisai and Biogen in January 2023. The drug subsequently converted to full approval later that year after a Phase 3 trial showed it slowed cognitive decline by approximately 27 per cent.
The FDA applies the same evidentiary standard for FDA accelerated approval as for traditional approval, meaning the benefit-risk profile must still be favourable. What the pathway acknowledges, however, is that residual uncertainty exists about whether the surrogate endpoint will translate into real-world clinical benefit. In exchange for earlier market access, drug sponsors commit to conducting post-approval confirmatory trials to verify that the anticipated benefit is genuine.
How the Pathway Works in Practice
To qualify for FDA accelerated approval, a drug must target a serious or life-threatening condition, offer therapeutic benefit over existing treatments, and demonstrate an effect on a surrogate or intermediate endpoint reasonably likely to predict clinical benefit. The FDA defines a serious condition as one associated with morbidity having a substantial impact on day-to-day functioning, including diseases that may be life-threatening or that cause irreversible consequences if left untreated.
Once accelerated approval is granted, the drug enters the market while confirmatory trials continue. If those trials verify genuine clinical benefit, the approval converts to traditional full approval. If the confirmatory data does not support continued authorisation, the FDA may withdraw the product from the market.
This structure has allowed transformative medicines to reach patients years ahead of when they might otherwise have become available. Merck’s pembrolizumab (Keytruda) received its initial accelerated approval in September 2014 for unresectable or metastatic melanoma, based on tumour response rate. It went on to become one of the most widely prescribed cancer immunotherapies in the world, with subsequent confirmatory data enabling full approval across multiple indications. Bristol Myers Squibb’s nivolumab, marketed as Opdivo, and Eli Lilly’s selpercatinib, marketed as Retevmo, followed comparable routes through the accelerated pathway to reach patients in biomarker-defined oncology indications.
Not all journeys have ended as successfully. A study published in 2024 analysed 167 accelerated approval indications for cancer drugs granted between 1992 and 2022, with outcomes assessed as of August 2024. Of those, 31 indications, roughly 19 per cent, had been withdrawn, with the majority of withdrawals concentrated in the five years to 2024. That acceleration in enforcement reflected a deliberate shift in policy as the FDA and Congress moved to close longstanding gaps in the system.
The Confirmation Problem
The central tension in the FDA accelerated approval programme has always been the gap between early market entry and the subsequent obligation to prove clinical value. For much of its history, the FDA had limited tools to compel timely completion of confirmatory trials. Some drugs remained commercially available for years after their confirmatory evidence failed to emerge, or actively failed to demonstrate benefit.
A 2022 report from the Department of Health and Human Services Office of Inspector General found that over one-third of drugs granted accelerated approval had incomplete confirmatory trials, with 34 per cent of those with incomplete trials running past their original planned completion date. The problem was compounded by a practical recruitment challenge: once a drug is commercially available, patients have little incentive to enrol in a randomised confirmatory trial when they can already access the therapy outside a clinical setting.
A separate analysis found that of 46 cancer drugs granted accelerated approval in a specific cohort, 41 per cent failed to demonstrate clinical benefit in confirmatory trials, and a further 15 per cent lacked confirmatory data altogether, leaving only 43 per cent with demonstrated clinical benefit. Research on gastrointestinal cancer approvals similarly showed that 66.7 per cent of accelerated approvals in that field remained pending confirmation as of January 2025, with 20 per cent ultimately withdrawn.
Legislative Reform and New Guidance
Congress moved to address these shortcomings through the Food and Drug Omnibus Reform Act (FDORA), enacted on 29 December 2022 as part of the Consolidated Appropriations Act. FDORA substantially strengthened the FDA’s authority over the accelerated approval process. It granted the agency explicit power to require confirmatory trials to be underway at the time of approval, or within a specified period thereafter, rather than simply committing to initiate them post-approval. Failure to conduct a post-approval study with due diligence became a new prohibited act under the Federal Food, Drug, and Cosmetic Act. FDORA also created an expedited withdrawal procedure that removes the requirement for a formal public hearing, a process that had previously made withdrawal slow and difficult.
Building on FDORA, the FDA issued a major draft guidance document in December 2024 titled “Expedited Program for Serious Conditions: Accelerated Approval of Drugs and Biologics,” followed by a further draft guidance in January 2025 focused specifically on when a confirmatory trial would be considered formally underway. Together, these documents represent the most detailed articulation of FDA accelerated approval expectations to date, covering endpoint selection, trial design, and the precise conditions under which the agency will act to withdraw authorisation.
The December 2024 guidance made clear that the suitability of any proposed surrogate endpoint will depend on disease context, the magnitude and duration of the observed effect, and the existing evidence base linking the surrogate to meaningful clinical outcomes. The guidance also confirmed that the new expedited withdrawal process had already been used once, in 2024, to withdraw approval for melphalan flufenamide, sold as Pepaxto.
Criticism and Ongoing Debate
The FDA accelerated approval pathway continues to draw substantive academic and clinical debate. Critics argue that surrogate endpoints in oncology frequently fail to correlate with overall survival or quality of life, meaning patients, payers, and health systems may be accessing and funding drugs whose real-world benefit remains uncertain. The National Center for Health Research, in its February 2025 public comment on the draft guidance, called on the FDA to require and enforce timely confirmatory trials that demonstrate meaningful clinical benefit rather than relying on surrogate metrics that may not translate to improved outcomes.
Proponents counter that the pathway is essential for patients with no alternative options. Waiting for mature survival data, they argue, would mean years of delay for people whose conditions are immediately life-threatening. The goal is not to abandon the accelerated pathway but to enforce the confirmatory obligation consistently, which is exactly what FDORA and the 2024 and 2025 guidance documents are designed to achieve.
The FDA’s capacity to implement these reforms is itself under scrutiny. Cuts to staffing across federal health agencies, introduced from early 2025 onwards through the Department of Government Efficiency, placed pressure on FDA review capacity. Kenneth Kaitin, a senior fellow at Tufts University School of Medicine, warned that concentrating redundancies among newer staff risked breaking the institutional learning chain, with long-term consequences for regulatory expertise.
The Pathway Today
FDA accelerated approval remains a highly active regulatory mechanism. The FDA’s 2025 novel drug approvals report listed accelerated approval among the expedited programmes applied across that year’s cohort. In the first quarter of 2026, zongertinib received expanded accelerated approval for HER2-mutant non-small cell lung cancer, extending its use to newly diagnosed patients. Semaglutide received FDA accelerated approval in August 2025 for metabolic dysfunction-associated steatohepatitis, demonstrating that the pathway is no longer the exclusive preserve of oncology.
Understanding how FDA accelerated approval operates has become non-negotiable for those working in pharma, biotech, clinical development, regulatory affairs, and investment. It shapes deal valuations, licensing strategies, and patient access decisions in ways that extend well beyond the regulatory filing itself. For context on how approval timelines are structured more broadly, see the guide to PDUFA dates and FDA drug approval deadlines that provides a useful companion overview of the agency’s review process.
The programme born from the urgency of the AIDS crisis has since reshaped access to treatments in oncology, neurology, and rare disease. The challenge ahead for the FDA is to honour that original purpose while ensuring the promise embedded in every accelerated approval is ultimately verified, and that patients are not left exposed to treatments whose clinical value was never confirmed.
