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ClinicalTrials.gov 1,688 recruiting now below national open share #11 of 52 states

Arizona: below-average open trial sites

1,688 of 5,607 in-state trials are recruiting (30%); below the 37% national average by 7 percentage points.

According to ClinicalTrials.gov-derived indexes, Arizona sits in the upper quartile of US states by in-state trial count (#11 of 52 states by registered in-state trial count).

Arizona: 5,607 US clinical trials with in-state sites, 1,688 recruiting.

Arizona has 5,607 registered US clinical trials with a study site in-state, 1,688 of them currently recruiting (below the 37% national average by 7 percentage points). 1,954 of these trials are in Phase 3 (late-stage) and 1,449 in Phase 2. The most frequently studied condition in Arizona is Breast Cancer, with 111 linked trials.

Upper-quartile research density

Arizona sits in the upper quartile by in-state trial count. Open share is below the 37% national average by 7 percentage points - denser than most states, still short of the top-decile research hubs.

Below-average open enrollment

Arizona still shows 1,688 recruiting of 5,607 in-state trials (30% open), but below the 37% national average by 7 percentage points, so archived statuses weigh heavier than the national baseline.

30%
open (below national share)
1,688
still recruiting despite cool share
1,449
Phase 2 rows in this footprint
111
top: Breast Cancer

Recruiting share is below the 37% national average by 7 percentage points. Counts include every study with at least one recorded site in the state. Registry reference only, not medical advice.

Arizona vs all states by indexed in-state trial count

Where this state's ClinicalTrials.gov site count sits among every state with at least one listed trial (coverage density, not care quality)

5,607 Top 21% more indexed trials than 79% of 52 states

States, banded by indexed in-state trial count

Each bar is a band; taller bars hold more states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source ClinicalTrials.gov · 2026-08-08

Key findings

What ClinicalTrials.gov does not surface for Arizona on its own pages , computed from the registry mirror as of 2026-08-08. Each line carries its own denominator so it can be quoted as it stands.

  1. Arizona open-enrollment share sits below the national baseline.

    1,688 of 5,607 in-state trials (30.1%) are recruiting, against 37% nationally (-6.9 percentage points). Counts include every study with at least one recorded site in the state.

  2. Arizona trial sites spread across 8 city hubs.

    Phoenix lists 2,754 of 5,607 in-state trials (49.1%) across 1,101 named facilities. Cities need five or more listed trials to appear here; locations are as filed by sponsors.

  3. Breast Cancer is the most-studied condition in Arizona.

    111 of 5,607 in-state trials (2%) list Breast Cancer. That is a local concentration figure, not a national disease ranking.

  4. Arizona sponsorship is fragmented across many organizations.

    National Cancer Institute (NCI) appears on 231 of 5,607 in-state trials (4.1%). Sponsor identity is as filed on ClinicalTrials.gov.

  5. 2,482 Arizona trials carry a completed status.

    2,482 of 5,607 (44.3%) are completed. The open share above is the remainder that still lists recruiting.

Phase 31,954Phase 21,449NA742Phase 1696Phase 4215Early Phase 125
Treemap Treemap of 15 categories, sized proportional to value. Breast Cancer 111 Non-Small Cell Lung… 73 Prostate Cancer 72 Obesity 71 Diabetes Mel… 60 Multiple Mye… 60 Asthma 50 Heart Failure 50 Cancer 49 Healthy 46 Ovarian Cancer 45 Rheumatoid Ar… 43 Colorectal Cancer 41 HIV Infections 36 Alzheimer Disease 36

By Status

StatusTrial count
Completed 2,482
Recruiting 1,688
Active 1,437

By Phase

PhaseTrial count
Phase 3 1,954
Phase 2 1,449
NA 742
Phase 1 696
Phase 4 215
Early Phase 1 25

Where trials run in Arizona

Phoenix carries 2,754 of Arizona's 5,607 indexed trials (49%) across 1,101 named sites, ahead of Tucson at 1,809. 8 cities clear five listed trials, together naming 3,033 distinct sites.

City Trials Listed sites
Phoenix 2,754 1,101
Tucson 1,809 736
Scottsdale 1,294 434
Gilbert 372 139
Chandler 363 187
Mesa 335 163
Tempe 254 127
Glendale 219 146

Distinct trials and named sites per city, as filed with ClinicalTrials.gov; cities under five trials omitted. Vintage 2026-08-08.

Volume high

Arizona indexes 5,607 in-state trials (p80 by registry volume among 52 states with sites).

Arizona: in-state trial volume sits in the high tercile

Sites spread across 8 cities with five or more listed trials, led by Phoenix (2,754, 49% of the state total) and Tucson (1,809), together naming 3,033 distinct research locations.

Phase mix: 1,954 Phase 3 vs 1,449 Phase 2 (balanced across stages).

Top condition: Breast Cancer (111 trials); top sponsor National Cancer Institute (NCI) (231).

high-volume · low-open figures (5,607 trials · 30% open) describe registry geography under the volume high read, not clinic capacity or protocol fit. Confirm status on ClinicalTrials.gov before acting.

States near Arizona on in-state trial volume

Cross-state peers under the volume high read (high-volume · low-open), not the same-state browse list.

Similar high-volume hubs (± open share)

Similar low-open peers (± trial volume)

  • Nebraska · 29% recruiting · 1,301 trials
  • Kansas · 29% recruiting · 2,080 trials
  • South Dakota · 31% recruiting · 273 trials
  • New Mexico · 29% recruiting · 579 trials
  • Indiana · 29% recruiting · 3,113 trials
Source: ClinicalTrials.gov, the US trial registry maintained by the National Library of Medicine, part of the NIH. Arizona series (high-volume · low-open · volume high) retrieved and formatted by PlainTrial, see methodology.