State of Trial Enrollment 2026

What are the main findings?

Registry counts are weighted to oncology, and published research puts most of the friction at the site: finding eligible patients, the staff time that takes, and consent forms patients struggle to read.

• Oncology leads the pool. Cancer keywords match 7,074 of the 22,041 US recruiting studies, or 32.1%.^⁠[1]
• Most trials reach their goal, but late. In Tufts CSDD's 2013 analysis, 89% of trials met enrollment goals, typically after nearly doubling the original timeline.^⁠[2]
• Cancer drug trials enroll mostly outside the US. In the pivotal trials behind FDA's 2025 novel cancer drug approvals, 80% of participants were enrolled outside the US.^⁠[18]

What the report covers

1. 1Recruiting trials by therapeutic area and geography
2. 2Trial enrollment performance
3. 3Site performance
4. 4Screen failure
5. 5Coordinator workload
6. 6Consent
7. 7Representation
8. 8Methods

How many trials are recruiting, and where?

On September 21, 2026, 22,041 studies on ClinicalTrials.gov had a status of Recruiting and at least one US location. Cancer keywords matched 7,074 of them, more than twice any other area.^⁠[1]

Keyword lists overlap and many studies match none, so the bars are counts, not shares of the total.^⁠[1]

A count shows where sponsors have placed studies, not which are enrolling on schedule. The state and region pages break each count down by area.

How often do trials hit enrollment targets?

Most trials get there, but late. In Tufts CSDD's 2013 analysis of more than 150 studies, 89% of trials met their enrollment goals, but reaching them typically meant nearly doubling the original timeline.^⁠[2] A registry study shows how often trials fall short: of 2,579 Phase 2 and 3 trials that closed in 2011, 19% were terminated for failed accrual or finished below 85% of planned enrollment, affecting 48,027 enrolled patients.^⁠[3]

Timelines are getting longer. In Tufts CSDD data presented at SCOPE 2024, enrollment duration, from first patient first visit to last patient last visit, rose 36.9% from 2010 to 2020.^⁠[4] IQVIA reports that global trial durations increased in 2025 and the intervals between trials in a development program grew by 3 months.^⁠[5]

How do sites perform against enrollment targets?

Newer data point the same way. In a 2023 Phesi analysis of 173 cancer trials with 11,826 sites, reported by Labiotech, 19% of sites enrolled just one patient.^⁠[7] At SCOPE 2024, Tufts CSDD reported that about 40% of the North American sites a sponsor looks to engage never activate.^⁠[4] Start-up speed depends on site type: in WCG's 2025 survey, 54% of independent sites and physician practices said they can start a study in under 60 days, compared with 9% of academic centers, hospitals, health systems and site networks.^⁠[8]

The guide to how sponsors choose sites shows how these numbers feed site selection.

How many screened patients fail screening?

There is no single industry rate, and published figures use different denominators. One cross-sponsor benchmark is the Tufts CSDD randomization rate: patients enrolled divided by patients screened. In its 2022 benchmark of 187 industry protocols approved from 2013 to 2018, Phase III protocols randomized 70.7% of screened patients on average and had a mean of 30.4 eligibility criteria.^⁠[9]

Rates vary by disease and by site. At one large inflammatory bowel disease trial center in Belgium, 17.1% of 642 screenings for sponsored trials from 2008 to 2021 failed, compared with 39.2% across the global populations of the same trials. The authors judged that about one-fourth of the center's screen failures could have been avoided by more thorough pre-screening.^⁠[10] The fair comparison for a site is its own rate against the sponsor's study-wide rate for the same protocol.

The screen failure guide covers rates by therapeutic area, the causes a chart can predict, and how to track avoidable failures.

How much of the work falls on coordinators?

Finding patients takes staff time. In a 2012 study at one academic cancer center that tracked screening in real time, the largest share of eligibility evaluations (35.8%) took 10 to 30 minutes, and more than 10% took 2 to 4 hours. Finding, screening and enrolling one patient took 3.4 to 8.8 hours of staff time, depending on study phase.^⁠[12]

The people doing that work have been hard to keep. In SCRS's 2022 site survey, sites reported turnover of patient-facing staff of 35% to 61%, against 10% to 37% in a typical year.^⁠[13] WCG's 2025 survey of 611 sites suggests some stabilization: 45% reported no change in staffing levels over the prior year.^⁠[8]

Evidence on software is thin. Tufts CSDD reported in early 2025 that AI support for trial activity yields time savings of 18%, but only that headline is public, not the tasks or sample behind it.^⁠[11]

What does consent do to enrollment and retention?

Consent forms are written above the average US adult's reading level. Across 798 federally funded US trials, consent forms averaged a Flesch-Kincaid grade level of 12.0, against an 8th-grade average for US adults. In risk-adjusted analysis, each added grade level was associated with a 16% higher dropout rate.^⁠[14]

Understanding of core trial concepts is low. In a 2015 meta-analysis of 103 studies, only 52.1% of trial participants understood randomization.^⁠[15] Advarra, without naming its primary source, reports that 35% of patients who dropped out early found the consent form hard to understand, against 16% of those who completed.^⁠[16]

A quick check for a site: run the consent form through a Flesch-Kincaid readability test. The consent form guide covers what length and reading level do to retention.

Who is enrolled, and who is left out?

FDA's Drug Trials Snapshots describe participants in the pivotal trials behind each year's novel drug approvals. FDA reports ranges by program and averages by therapeutic area, not a pooled national share.^⁠[17],[18]

Access starts with an invitation. In a nationally representative 2020 survey, only 9% of US adults had ever been invited to join a clinical trial, but 47% of those invited took part. Rural residents had about one-third the odds of an invitation that urban residents had.^⁠[19] In an April 2026 Harris Poll for the PAN Foundation, 64% of US adults with chronic conditions said a provider had never discussed trials with them, while 71% said they would be likely to take part if given the opportunity.^⁠[20]

The federal diversity requirement has not taken effect yet. The Food and Drug Omnibus Reform Act of 2022 requires Diversity Action Plans for Phase 3 and other pivotal drug studies and certain device studies, but only for studies that begin enrolling 180 days after FDA publishes final guidance.^⁠[21] As of September 2026, FDA's guidance page still lists the June 2024 document as a draft.^⁠[22]

How was this report built?

• Registry data. ClinicalTrials.gov API v2, queried September 21, 2026: status Recruiting, a location search per state or for the United States, and the API's condition search per area. Counts are studies, not sites or patients.^⁠[1]
• Area keywords. Each area is a list of main conditions. Oncology is cancer, neoplasm, carcinoma, lymphoma or leukemia. Obesity and metabolic includes type 2 diabetes. Neurology and pain both include migraine.
• Location matching. The location search matches text, so a state name can also match another place, such as the country of Georgia or West Virginia. This can inflate some Southeast counts, and the figures are not corrected for it.
• Published research. Each figure was checked against its source text. Older benchmarks carry their year; figures we could not trace to a source are left out.
• Bond's figures. Bond's product claims appear only in marked callouts, cited to Bond's website. No finding comes from Bond customer data.

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