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ClinicalTrials.gov 49 recruiting now early-phase tilt #64 of 28,707 conditions

Cystic Fibrosis: early-phase trial registry

49 of 170 indexed Cystic Fibrosis trials are currently recruiting, with more weight in Phase 1-2.

Corpus placement: #64 of 28,707 conditions by registered trial count.

170 US clinical trials · 49 currently recruiting · #64 of 28,707 conditions by registered trial count

Cystic Fibrosis: 170 US clinical trials tracked, 49 recruiting.

Cystic Fibrosis is the subject of 170 registered US clinical trials on ClinicalTrials.gov, 49 of them currently open to new participants. 34 are in Phase 3-4 (later-stage) and 61 in Phase 1-2 (earlier-stage). The most active sponsor is Vertex Pharmaceuticals Incorporated, running 20 of these trials.

Enrollment posture brief

Registry condition cystic-fibrosis

OPEN 49 | RECR 29% | LATE 34 | EARLY 61 | RANK #64 | SPON 20

Nearest open-share peer: Prostatic Neoplasms (29% recruiting · 66 trials)

Malignant Solid Neoplasm53.1%Epilepsy47.6%Traumatic Brain Injury43.6%Cystic Fibrosis (this)29%Bipolar Disorder22.7%
Open-enrollment share among volume-matched conditions near Cystic Fibrosis

Cystic Fibrosis lists 49 open slots (29% of 170 indexed trials). Peers are matched on registered volume, not therapeutic-area browse lists. How peer matching works →

Key findings

What ClinicalTrials.gov does not surface for Cystic Fibrosis 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. Cystic Fibrosis is recruiting below its size-band peers.

    49 of 170 indexed trials (28.8%) are open to enrollment, against a 37.1% average across 139 conditions with 100+ trials. The peer set uses the same ClinicalTrials.gov-derived counts as this page.

  2. Sponsorship of Cystic Fibrosis trials is spread across many organizations.

    Vertex Pharmaceuticals Incorporated accounts for 20 of 170 trials (11.8%). 84 distinct sponsors appear on at least one study for this condition label.

  3. Most Cystic Fibrosis trials plan to enrol fewer than 100 people.

    Median target enrolment is 59 among the 170 trials that report a genuine target (sentinel values excluded). 107 of those (62.9%) plan for fewer than 100 participants.

  4. Cystic Fibrosis research is mostly interventional.

    121 interventional and 49 observational studies make up this index (71.2% interventional). Study type is sponsor-reported on ClinicalTrials.gov.

Phase 134Phase 227Phase 319Phase 415

Open and recent trials

170 total, page 1 of 4

RECRUITING 3,500 participants

Role of Genetic Factors in the Development of Lung Disease

National Heart, Lung, and Blood Institute (NHLBI)

NCT00001532

RECRUITING 1,000 participants

FLOWER: Following Longitudinal Outcomes With Epidemiology for Rare Diseases

xCures

NCT06539169

RECRUITING 900 participants

Natural History of Bronchiectasis

National Heart, Lung, and Blood Institute (NHLBI)

NCT00943514

RECRUITING NA 800 participants

Acoustic Waveform Respiratory Evaluation

Indiana University

NCT06512064

RECRUITING Phase 4 730 participants

Standardizing Treatments for Pulmonary Exacerbations - Aminoglycoside Study

Chris Goss

NCT05548283

RECRUITING 550 participants

Genetics of Insulin and Incretins in Cystic Fibrosis

Children's Hospital of Philadelphia

NCT01852448

RECRUITING 500 participants

Rare CFTR Mutation Cell Collection Protocol (RARE)

George Solomon

NCT03161808

RECRUITING NA 430 participants

Streamlined Treatment of Pulmonary Exacerbations in Pediatrics

University of Washington, the Collaborative Health Studies Coordinating Center

NCT06654752

RECRUITING 400 participants

A Research Study to Advance the CF Therapeutics Pipeline for People Without Modulators

Nicole Hamblett

NCT06504589

RECRUITING 400 participants

Natural History of Noncirrhotic Portal Hypertension

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

NCT02417740

RECRUITING Phase 1 260 participants

Hyperpolarized 129Xe MR Imaging of Lung Function in Healthy Volunteers and Subjects With Pulmonary Disease

Mario Castro, MD, MPH

NCT04624490

RECRUITING Phase 1 255 participants

Evaluation of VX-828 in Healthy Participants and in Participants With Cystic Fibrosis

Vertex Pharmaceuticals Incorporated

NCT06154447

RECRUITING NA 240 participants

Exercise in Child Health

University of California, Irvine

NCT05359991

RECRUITING Phase 3 210 participants

Evaluation of VX-121/Tezacaftor/Deutivacaftor in Cystic Fibrosis (CF) Participants 1 Through 11 Years of Age

Vertex Pharmaceuticals Incorporated

NCT05422222

RECRUITING 210 participants

Study to Evaluate Biological & Clinical Effects of Significantly Corrected CFTR Function in Infants & Young Children

Sonya Heltshe

NCT04509050

RECRUITING 200 participants

Restarting Triple Therapy With Robust Monitoring for Adverse Events (RETRIAL)

Boston Children's Hospital

NCT06683092

RECRUITING Phase 2 192 participants

A Phase 2 Study Evaluating Safety and Tolerability of RCT2100 (CFTR mRNA) in Healthy Participants and in Participants With CF

ReCode Therapeutics

NCT06237335

RECRUITING 170 participants

Impact of Sinus Surgery on Individuals With Cystic Fibrosis

University of California, Los Angeles

NCT04469439

RECRUITING 150 participants

Remote Sputum Collection in Cystic Fibrosis

University of Pennsylvania

NCT06950892

RECRUITING 146 participants

Health Outcomes of Parents With Cystic Fibrosis-Aim 2

University of Pittsburgh

NCT06296394

RECRUITING NA 132 participants

Lung Transplant READY CF 2: CARING CF Ancillary RCT

University of Washington

NCT06032273

RECRUITING Phase 1 128 participants

Dose Escalation Study Evaluating the Safety and Pharmacokinetics of VX-581 in Healthy Participants

Vertex Pharmaceuticals Incorporated

NCT07283770

RECRUITING Phase 4 100 participants

Markers of Osteoporosis in Cystic Fibrosis

University of Texas Southwestern Medical Center

NCT03921060

RECRUITING 100 participants

Regional Phenotyping of CF and Non-CF Bronchiectasis

Children's Hospital Medical Center, Cincinnati

NCT04793867

RECRUITING 90 participants

Role of Body Fat Distribution in Metabolic and Pulmonary Decline in Cystic Fibrosis (ORBIT-CF)

Emory University

NCT04002882

RECRUITING 80 participants

Sinus Disease in Young Children With Cystic Fibrosis

University of California, Los Angeles

NCT06191640

RECRUITING Phase 4 75 participants

Estrogen Supplementation and Bone Health in Women With CF

Johns Hopkins University

NCT05704036

RECRUITING Early Phase 1 61 participants

Hormonal Responses to a Mixed Meal in People With Cystic Fibrosis

University of Cincinnati

NCT06163482

RECRUITING NA 60 participants

FEED-Cystic Fibrosis (FEED-CF)

Emory University

NCT05766774

RECRUITING Early Phase 1 60 participants

Regional Monitoring of CF Lung Disease

Children's Hospital Medical Center, Cincinnati

NCT06339593

RECRUITING NA 50 participants

Testing Drug Efficacy in Cystic Fibrosis Through N-of-1 Trials

Children's Hospital Medical Center, Cincinnati

NCT04580368

RECRUITING NA 45 participants

Beta-cell Response to Incretin Hormones in Cystic Fibrosis

University of Pennsylvania

NCT01851694

RECRUITING Phase 4 44 participants

BEGIN Novel ImagiNG Biomarkers

Children's Hospital Medical Center, Cincinnati

NCT05517655

RECRUITING Phase 2 42 participants

Targeting Inflammation With Losartan to Improve Response to Modulator Therapy in Cystic Fibrosis.

University of Kansas Medical Center

NCT06364176

RECRUITING NA 40 participants

A Pilot and Feasibility Study to Evaluate High vs Low Glycemic Index Mixed Meal Tolerance Test in Adolescents and Young Adults With Cystic Fibrosis

Emory University

NCT06350149

RECRUITING Phase 1 39 participants

A Phase 1/2 Study of VX-522 in Participants With Cystic Fibrosis (CF)

Vertex Pharmaceuticals Incorporated

NCT05668741

RECRUITING 36 participants

Skeletal Health and Bone Marrow Composition in Adolescents With Cystic Fibrosis

Massachusetts General Hospital

NCT06216704

RECRUITING 30 participants

Impact of Highly Effective Modulator Therapy on the Cystic Fibrosis Microbiome

Dartmouth-Hitchcock Medical Center

NCT05982795

RECRUITING NA 30 participants

Skin-interfaced Colorimetric Bifluidic Sweat Sensor Device for the Diagnosis of Cystic Fibrosis (CF)

Milton S. Hershey Medical Center

NCT05998629

RECRUITING 30 participants

Continuous Glucose Monitoring and OGTT Screen for Cystic Fibrosis Related Diabetes in Cystic Fibrosis

Medical College of Wisconsin

NCT06560463

RECRUITING 30 participants

Quantitation and Spatial Registration of Airways Dysfunction With Dynamic 19F MRI in Cystic Fibrosis

University of North Carolina, Chapel Hill

NCT06057714

RECRUITING Phase 2 30 participants

GLP-1 Agonist Therapy in Cystic Fibrosis-Related Glucose Intolerance

University of Pennsylvania

NCT04731272

RECRUITING Phase 3 25 participants

Assessing Tenapanor as a Treatment of CF-related Constipation.

Massachusetts General Hospital

NCT06810167

RECRUITING Phase 2 24 participants

Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of SPL84 in Patients with Cystic Fibrosis

SpliSense

NCT06429176

RECRUITING Early Phase 1 20 participants

Personalized Theratyping Trial

George Solomon

NCT03587961

RECRUITING Phase 1 15 participants

A Phase 1/2 Trial of SP-101 for the Treatment of Cystic Fibrosis (CF)

Spirovant Sciences

NCT06526923

RECRUITING NA 15 participants

The Effects of a Low Glycemic Load Diet on Dysglycemia and Body Composition in Adults With Cystic Fibrosis-Related Diabetes

Rhode Island Hospital

NCT05723445

RECRUITING Phase 1 12 participants

A Study Assessing KB407 for the Treatment of Cystic Fibrosis

Krystal Biotech

NCT05504837

RECRUITING Phase 2 12 participants

Safety, Tolerability and Efficacy Study of ARCT-032 in People With Cystic Fibrosis

Arcturus Therapeutics

NCT06747858

ACTIVE NOT RECRUITING 5,000 participants

CHaractErizing CFTR Modulated Changes in Sweat Chloride and Their Association With Clinical Outcomes

Nicole Hamblett

NCT03350828

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Phase Distribution

PhaseTrial count
Phase 1 34
Phase 2 27
Phase 3 19
Phase 4 15

Named interventions

Most-linked intervention names on Cystic Fibrosis records (sponsor-reported on ClinicalTrials.gov). Counts are trial links, not unique products.

Placebo Drug
17 trials
Ivacaftor Drug
6 trials
IVA Drug
5 trials
Placebo Other
5 trials
Lumacaftor Drug
3 trials
VX-121/TEZ/D-IVA Drug
3 trials
Liprotamase Drug
2 trials
TEZ/IVA Drug
2 trials

US sites by state

Facility locations filed on Cystic Fibrosis trials. A trial with sites in several states counts in each.

Colorado 55 trials
California 52 trials
Massachusetts 45 trials
Florida 45 trials
Pennsylvania 42 trials
Ohio 42 trials
Alabama 42 trials
Illinois 41 trials

Source: ClinicalTrials.gov, National Library of Medicine. Data is informational only.

What to do with this Cystic Fibrosis page

170 registered trials, 49 currently recruiting, is a starting point for a conversation, not a diagnosis or a recommendation.

Trial and recruiting counts reflect ClinicalTrials.gov registry status as of the data vintage above; individual trial eligibility and enrollment status can change.

Every figure on PlainTrial is rendered directly from the ClinicalTrials.gov registry, no number is typed in by an editor. This Cystic Fibrosis condition card totals 170 registered trials; most-linked intervention Placebo; top US site state Colorado. See our editorial standards & corrections policy, the methodology behind these numbers, the data changelog, or report a data error.