The Accelerated-Approval Bargain: Surrogate Endpoints, Confirmatory Trials, and Faster Withdrawal

Accelerated approval is a conditional deal. It lets the U.S. Food and Drug Administration approve a drug for a serious condition based on a surrogate endpoint that is "reasonably likely to predict clinical benefit," rather than waiting for direct evidence that patients live longer or better. In exchange, the sponsor must run a confirmatory trial to verify the real-world benefit, and if that benefit is not confirmed, approval can be withdrawn. The 2022 Food and Drug Omnibus Reform Act, often described as the 2023 accelerated-approval reform, tightened both sides of that bargain: it gave FDA clearer authority to require the confirmatory trial be underway before approval, to specify its conditions, and to withdraw approval through a faster, defined process if the benefit fails to materialize.

This piece explains the mechanism, not any policy position, administration, or party. It is educational and not medical advice.

What a surrogate endpoint actually is

A clinical endpoint measures something patients directly feel or experience: survival, symptoms, hospitalizations, disability. A surrogate endpoint is a laboratory measurement, imaging finding, or physical sign that stands in for a clinical endpoint. Tumor shrinkage stands in for living longer. A drop in a blood biomarker stands in for slowed disease. The surrogate is attractive because it can be measured sooner and in fewer patients, so a drug for a life-threatening illness can reach people years earlier.

The legal test is precise. Under the accelerated approval pathway, FDA may approve a drug that shows an effect on a surrogate endpoint "reasonably likely to predict clinical benefit," or on an intermediate clinical endpoint measurable earlier than irreversible morbidity or mortality (FDA, Accelerated Approval Program). "Reasonably likely" is a deliberately lower bar than "established." It reflects a scientific judgment that the surrogate probably tracks benefit, made under uncertainty, for a serious condition where waiting has its own cost.

That uncertainty is the whole point of the bargain. A surrogate can move in the right direction while the clinical benefit never arrives. A tumor can shrink without the patient living longer. So accelerated approval is structured as approval-plus-obligation, not approval-and-done.

The confirmatory trial: the other half of the deal

When FDA grants accelerated approval, it requires the sponsor to conduct a post-approval confirmatory trial designed to verify and describe the anticipated effect on a clinical outcome (FDA guidance, Expedited Programs for Serious Conditions). The drug is on the market and reaching patients, but the question it was approved on remains formally open until that trial reads out.

Three outcomes are possible. The trial confirms benefit, and the approval converts to traditional approval. The trial fails to confirm benefit, and the approval is subject to withdrawal. Or the trial drags on for years while the drug stays on the market on the strength of the surrogate alone. Historically, the third outcome, delay, was the recurring weakness. Confirmatory trials sometimes started slowly or lingered unfinished, which meant the "conditional" part of a conditional approval could stretch well past its intended window.

What FDORA changed in the mechanism

The Food and Drug Omnibus Reform Act, enacted in December 2022 as part of the Consolidated Appropriations Act, amended section 506(c) of the Federal Food, Drug, and Cosmetic Act to strengthen FDA's tools at each pressure point.

Trials underway before, not after

FDA gained explicit authority to require, as appropriate, that a confirmatory study or studies be underway before accelerated approval is granted, or within a specified time after approval. This addresses the delay problem at its source. Instead of a promise to begin a trial later, the sponsor can be required to already be enrolling patients when the drug launches. In a draft guidance published in the Federal Register in January 2025, FDA described the factors it weighs in deciding whether a trial is sufficiently "underway," including a clear target completion date, demonstrated progress, and initiated patient enrollment (FDA draft guidance, Determining Whether a Confirmatory Trial Is Underway). As a draft, that guidance describes FDA's proposed thinking rather than a final rule.

Conditions specified up front

FDORA directs FDA to specify the conditions of the required post-approval studies. That can include enrollment targets, milestones, and completion dates. Pinning down the terms at approval reduces later ambiguity about what the sponsor owes and when.

More frequent reporting

The law increased the cadence of accountability. Sponsors report progress on required post-approval studies at least every 180 days, and FDA makes that status information public. More frequent, published reporting makes a stalled trial visible earlier.

A faster path to withdrawal

Perhaps the most consequential change is on the exit. FDORA created expedited procedures to withdraw an accelerated approval, available when a confirmatory trial fails to verify benefit, a sponsor fails to conduct a required trial with due diligence, or other statutory grounds are met. The streamlined process still includes procedural protections: written notice and explanation, an opportunity for the sponsor to meet with the agency, the possibility of advisory-committee input, and publication of the proposal for public comment. The design is a withdrawal mechanism that is quicker and more defined than the older, more cumbersome route, while still giving the sponsor a hearing.

An internal coordinating council

FDORA also called for FDA to establish an internal Accelerated Approval Program Council to promote consistency in how the pathway is used across the agency, with public reporting on its activity. This is an institutional check on drift, aimed at keeping standards uniform across different review divisions.

Why the trade-off is genuinely hard

The tension is not a flaw to be engineered away; it is the reason the pathway exists. Demand more certainty before approval, and patients with serious illness wait longer for drugs that may help them, some of whom will not have that time. Approve on weaker surrogate evidence, and some drugs reach the market whose promised benefit never materializes, exposing patients to cost and side effects for an uncertain gain. Accelerated approval places that trade-off inside a single structure: earlier access, purchased with a binding obligation to prove the benefit, backed by a defined way to reverse course.

What FDORA adjusted is the enforceability of the second half. The surrogate-endpoint standard, "reasonably likely to predict clinical benefit," is unchanged. What changed is how firmly the confirmatory obligation is set at the front end and how efficiently an unverified approval can be unwound at the back end. Whether one views any particular approval as too fast or too cautious, the underlying architecture is a bargain: speed now, in exchange for proof later and a credible mechanism to act if the proof does not come.