Site growth

Why research sites are getting fewer studies, and what busy sites do differently

By TrialNotice · Updated
Research site owner reviewing study opportunities on a laptop in a quiet office
Short answerMany sites are seeing fewer studies because industry trial starts fell 17% from their 2021 peak before stabilizing, while each trial now spreads across far more sites: the average Phase III trial grew from 65 to 106 sites between 2020 and 2025, per Tufts CSDD. Sponsors also return to familiar sites. The busy sites stand out on specialization, honest feasibility, and proof they can deliver patients.

Is it just my site?

No. Industry wide, clinical trial starts declined 17% from 2021 to 2024, after the COVID peak (IQVIA Institute), then stabilized at roughly pre pandemic levels (IQVIA). Sites at the 2025 SCRS summit described a reduced flow of new opportunities and elevated study cancellations over the prior 12 to 18 months, especially in vaccines (Bourne Partners).

What changed in how studies are distributed?

  • More sites per trial. Tufts CSDD data shows the average Phase III trial grew from 65 to 106 investigative sites and from 9 to 13 countries between 2020 and 2025 (Bourne Partners, citing Tufts CSDD). More sites share each study, and each enrolls fewer patients.
  • Sponsors favor familiar sites. Only 28% of engaged sites are new relationships, and familiar sites finish startup 9.9 weeks faster (Tufts CSDD).
  • The sponsor mix shifted. Emerging biopharma companies ran 68% of trial starts in 2025, up from 56% in 2019, and oncology alone was 38% of starts (IQVIA).
  • Activation is selective. Only 62% of North American sites that sponsors engage go on to activate (Tufts CSDD).

What do the busy sites do differently?

  1. They say no to the wrong studies. Sites turn down studies about 20% of the time, and sponsors at SCRS described an honest decline as relationship building (Bourne Partners).
  2. They specialize visibly. Sponsors want investigators as invested in the indication as they are.
  3. They make themselves findable, including registering investigators on databases sponsors search, such as investigatordatabank.org (Bourne Partners).
  4. They deliver, so they become one of the familiar sites. In 2020, 66% of principal investigators filed only one Form 1572 (Tufts CSDD), so a site that keeps delivering study after study stands out.
  5. They can prove patient access with something better than a guess.

Why does patient access decide so much?

Sponsors are always looking for sites that bring new patient populations, and they weigh access to patients in every feasibility review (Bourne Partners). A site with documented referral relationships with local specialists can answer "where will your patients come from?" with names and numbers. That answer wins studies, and delivering on it wins the next one.

Related: how research sites get more studies from sponsors.

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Sources

  1. IQVIA Institute, "Global Trends in R&D 2025" (report PDF)
  2. IQVIA, "Stabilization and improvement seen in multiple key biopharma R&D metrics"
  3. IQVIA, "Therapeutic Areas Driving Clinical Trial Growth" (2026)
  4. Bourne Partners, "Update on the Fundamentals of Clinical Trial Sites" (SCRS Global Site Solutions Summit takeaways, October 2025)
  5. Tufts CSDD, first comprehensive clinical site initiation benchmark (2018), via GlobeNewswire
  6. Applied Clinical Trials, "Tracking Change in the Global Investigative Site Landscape" (Tufts CSDD)
  7. Clinical Trial Vanguard, "Tufts CSDD: New Insights on The Clinical Trial Industry" (SCOPE 2024)

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