FDA Finalizes Three Cancer Trial Eligibility Guidances

FDA's Oncology Center of Excellence has finished a piece of unfinished business from 2024. On 27 July 2026 the Center posted final versions of three guidance documents on cancer clinical trial eligibility criteria — performance status, laboratory values, and washout periods and concomitant medications — with notices of availability running in the Federal Register the next day. All three were drafts for more than two years; sponsors now have FDA's finalized recommendation on the filters that decide who is allowed into a cancer trial in the first place.

Three filters, one problem

The three documents target the eligibility criteria that oncology protocols lean on most. Performance status is the scale — typically ECOG or Karnofsky — investigators use to judge whether a patient can carry out ordinary daily activities well enough to tolerate a study drug; FDA's guidance calls it “one of the most common eligibility criteria in oncology trials” and pushes sponsors to justify cutoffs against the actual pharmacology of the drug being tested, rather than defaulting to the most conservative threshold. Laboratory values does the same for blood-count, renal-function, and hepatic-function cutoffs, which have historically excluded patients — including many with the cancers most associated with organ impairment — without clinical justification specific to the drug in question. Washout periods and concomitant medications covers how long a patient must wait after a prior therapy, and which drugs they may keep taking, before enrolling; both can be set more conservatively than the trial drug's own pharmacokinetics require.

Why FDA is revisiting criteria it already regulates loosely

None of this is new territory for the Oncology Center of Excellence, which has spent a decade publishing similar guidance on broadening trial populations. What makes eligibility criteria a persistent target is the gap between who wants to enroll in a cancer trial and who is allowed to. Coverage of the final guidance has repeatedly cited the same figures: fewer than 5 percent of cancer patients currently receiving treatment are enrolled in a clinical trial, even though surveys put patient willingness to participate above 70 percent. FDA's guidance frames unnecessarily restrictive criteria as one of the mechanisms closing that gap — not the only one, but one squarely within the agency's own reach, since it reviews the protocols that set the criteria in the first place.

“Fostering efficient and more patient-centric clinical trial designs has long been a priority for the FDA's Oncology Center,” said Paul G. Kluetz, the Center's deputy director. “Assuring that eligibility for a cancer trial is not overly restrictive can facilitate enrollment of a more diverse and ‘real-world’ group of patients that are more reflective of who will use the therapy in routine care if approved.” That last clause is the operational argument for sponsors: a trial population narrower than the eventual patient population produces safety and efficacy data that may not hold up once the drug reaches the clinic.

What changed between draft and final

• Performance Status: retains the original framework, with new discussion of how enrolling lower-performance-status patients affects trial retention rates and the sample size needed to detect an effect — a practical concession to sponsors worried that broader eligibility complicates trial statistics.
• Laboratory Values: largely unchanged in structure from the 2024 draft; final text clarifies how sponsors should justify organ-function cutoffs against a drug's known pharmacology rather than convention.
• Washout Periods and Concomitant Medications: minor clarifying revisions; the core recommendation — basing washout length on the specific prior therapy's pharmacokinetics rather than a flat interval — carries through unchanged.

What sponsors and IRBs do with this now

Nothing in these three documents is enforceable in the way a regulation is: FDA guidance states the agency's current thinking, and a sponsor can use a different approach if it satisfies the underlying statute and regulations. What changes in practice is more mundane and more consequential — review divisions now have a final, citable text to hold protocol eligibility criteria against during IND review and at end-of-Phase-2 meetings, instead of a two-year-old draft. For sponsors currently drafting oncology protocols, that removes the ambiguity of designing to a draft that could still change, and it gives IRBs finalized language to weigh when a sponsor's proposed exclusion criteria go beyond what the drug's own data would justify.