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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 3 of 4

COMPLETED Phase 2 93 participants

Study of VX-809 in Cystic Fibrosis Subjects With the ∆F508-CFTR Gene Mutation

Vertex Pharmaceuticals Incorporated

NCT00865904

COMPLETED Phase 2 91 participants

A Study of the Dosing, Efficacy, and Safety of Oral Cysteamine in Adult Patients With Cystic Fibrosis Exacerbations

NovaBiotics

NCT03000348

COMPLETED Phase 2 87 participants

Efficacy and Safety Study of AeroVanc for the Treatment of Persistent MRSA Lung Infection in Cystic Fibrosis Patients

Savara

NCT01746095

COMPLETED 85 participants

A Prospective, Multicenter, Collaborative Study to Determine the Prevalence of Nontuberculous Mycobacteria (NTM) in Pediatric Patients With Cystic Fibrosis in Florida

University of Miami

NCT02198079

COMPLETED Phase 2 80 participants

A Study Evaluating the Safety of VX-152 Combination Therapy in Adults With Cystic Fibrosis

Vertex Pharmaceuticals Incorporated

NCT02951195

COMPLETED NA 78 participants

Behavioral & Nutritional Treatment to Help CF Preschoolers Grow

Children's Hospital Medical Center, Cincinnati

NCT00241969

COMPLETED Phase 2 77 participants

A Phase 2 Study to Evaluate Efficacy and Safety of VX-561 in Subjects Aged 18 Years and Older With Cystic Fibrosis

Vertex Pharmaceuticals Incorporated

NCT03911713

COMPLETED Phase 1 66 participants

Interferon Gamma-1b by Inhalation for the Treatment of Patients With Cystic Fibrosis

InterMune

NCT00043316

COMPLETED Phase 1 63 participants

To Assess the Safety, Tolerability and Pharmacokinetics of AZD5634 Following Inhaled and Intravenous (IV)Dose Administration

AstraZeneca

NCT02679729

COMPLETED Phase 3 62 participants

Study of Lumacaftor in Combination With Ivacaftor in Subjects 6 Through 11 Years of Age With Cystic Fibrosis, Homozygous for the F508del-CFTR Mutation

Vertex Pharmaceuticals Incorporated

NCT01897233

COMPLETED 59 participants

Association of Transcutaneous Pulse CO-oximetry With Inflammatory Lung Diseases

Boston Children's Hospital

NCT02831348

COMPLETED Phase 3 57 participants

A Study to Evaluate the Safety, Pharmacokinetics, and Pharmacodynamics of Ivacaftor in Subjects With Cystic Fibrosis Who Are Less Than 24 Months of Age and Have an Ivacaftor-Responsive CFTR Mutation

Vertex Pharmaceuticals Incorporated

NCT02725567

COMPLETED 54 participants

Muscle Accrual and Function in Cystic Fibrosis-Impact of Glucose Intolerance

Children's Hospital of Philadelphia

NCT02776098

COMPLETED 53 participants

The Carrier Rates of Pseudomonas Aeruginosa in Family Members of Children With Cystic Fibrosis

Zafer Soultan

NCT01616862

COMPLETED 51 participants

A Decentralized Study to Evaluate Physical Activity and Cough Frequency Using Wearable Technology in Cystic Fibrosis

Vertex Pharmaceuticals Incorporated

NCT04923464

COMPLETED 50 participants

BioEnergetics and Metabolomics in Cystic Fibrosis

Emory University

NCT02225899

COMPLETED Phase 1 48 participants

Drug-Drug Interaction Study of VX-770 and VX-809 in Healthy Subjects

Vertex Pharmaceuticals Incorporated

NCT01216046

COMPLETED Phase 3 46 participants

Study to Evaluate Lumacaftor and Ivacaftor Combination Therapy in Subjects 12 Years and Older With Advanced Lung Disease

Vertex Pharmaceuticals Incorporated

NCT02390219

COMPLETED Phase 1 44 participants

Evaluation of Regional Ventilation Using 19F MRI of Inert Perfluorinated Gases Mixed With Oxygen

Hal C Charles

NCT01710449

COMPLETED Phase 1 42 participants

Study to Evaluate the Safety & Tolerability of MRT5005 Administered by Nebulization in Adults With Cystic Fibrosis

Sanofi

NCT03375047

COMPLETED Early Phase 1 42 participants

19F MRI to Evaluate Regional Ventilation in Healthy Subjects and Subjects With Cystic Fibrosis

University of North Carolina, Chapel Hill

NCT03489590

COMPLETED NA 40 participants

Technology-enabled Patient Support System for Self-management of CF

University of Alabama at Birmingham

NCT03910881

COMPLETED Phase 2 40 participants

Phase II Study of Growth Hormone in Children With Cystic Fibrosis

University of Utah

NCT00016445

COMPLETED Phase 1 40 participants

Safety, Pharmacokinetic and Pharmacodynamic Study of MP-376 in Patients With Cystic Fibrosis

Amgen

NCT00503490

COMPLETED Phase 1 40 participants

Safety Study of Inhaled 552-02 in Cystic Fibrosis Patients

Parion Sciences

NCT00274313

COMPLETED Phase 4 36 participants

A Study to Compare US Marketed Creon Manufactured With a Modernized Process at an Alternate Manufacturing Site and Manufactured With the Approved Manufacturing Process at an Alternate Active Pharmaceutical Ingredient Site, in Participants With Exocrine Pancreatic Insufficiency Due to Cystic Fibrosis

AbbVie

NCT03924947

COMPLETED Phase 1 36 participants

Safety and Efficacy of Sildenafil in Cystic Fibrosis (CF) Lung Disease

National Jewish Health

NCT00659529

COMPLETED NA 34 participants

Redox Imbalance and the Development of Cystic Fibrosis Diabetes

Emory University

NCT02202876

COMPLETED Phase 2 32 participants

Nasal Potential Studies Utilizing Cystic Fibrosis Transmembrane Regulator (CFTR) Modulators

University of Alabama at Birmingham

NCT01348204

COMPLETED Phase 1 32 participants

MAD Study Evaluating the Safety, Tolerability, and Pharmacokinetics of Cavosonstat (N91115) in Healthy Subjects (SNO-9)

Nivalis Therapeutics

NCT02934139

COMPLETED NA 30 participants

Pilot Trial of Phototherapy for Acute Depression in Hospitalized Cystic Fibrosis Patients

Nationwide Children's Hospital

NCT01822197

COMPLETED Phase 1 30 participants

Inhaled Xylitol Versus Saline in Stable Subjects With Cystic Fibrosis

Joseph Zabner

NCT01355796

COMPLETED Phase 2 29 participants

Persistent Methicillin Resistant Staphylococcus Aureus Eradication Protocol (PMEP)

Johns Hopkins University

NCT01594827

COMPLETED 24 participants

Energy Balance and Weight Gain With Ivacaftor Treatment

Children's Hospital of Philadelphia

NCT02141464

COMPLETED NA 24 participants

Ex-vivo Perfusion and Ventilation of Lungs Recovered From Non-Heart-Beating Donors to Assess Transplant Suitability

University of North Carolina, Chapel Hill

NCT01615484

COMPLETED Phase 2 22 participants

A Study to Test How Well BI 1291583 is Tolerated by People With Cystic Fibrosis Bronchiectasis (Clairafly™)

Boehringer Ingelheim

NCT05865886

COMPLETED NA 21 participants

FDG-PET Imaging in Young Cystic Fibrosis Patients

Washington University School of Medicine

NCT00846053

COMPLETED NA 21 participants

Absorptive Clearance in the Cystic Fibrosis Airway

University of Pittsburgh

NCT00541190

COMPLETED Phase 2 21 participants

Feasibility of Home-based Exercise Program for Adults With Cystic Fibrosis

University of Kansas Medical Center

NCT05239611

COMPLETED 20 participants

Longitudinal Assessment of Exercise Capacity and Vascular Function in Patients With CF

Augusta University

NCT03338595

COMPLETED Phase 1 20 participants

Hydroxychloroquine in Cystic Fibrosis

Vanderbilt University

NCT00311883

COMPLETED Phase 2 19 participants

Blood Flow and Vascular Function in Cystic Fibrosis

Augusta University

NCT02057458

COMPLETED Phase 2 19 participants

Effects of Sildenafil on CFTR-dependent Ion Transport Activity

National Jewish Health

NCT01132482

COMPLETED Phase 4 18 participants

Telavancin Pharmacokinetics in Cystic Fibrosis Patients

Joseph L. Kuti, PharmD

NCT03172793

COMPLETED Phase 1 18 participants

Safety and Tolerability of Inhaled Nitric Oxide in Patients With Cystic Fibrosis

Mallinckrodt

NCT00570349

COMPLETED Phase 4 17 participants

Comparison of Absorption of Vitamin D in Cystic Fibrosis

Emory University

NCT01880346

COMPLETED Phase 4 17 participants

Comparison of Airway Clearance Therapy in Cystic Fibrosis Using the Same VEST Therapy Device But With Different Settings

University of Minnesota

NCT00685035

COMPLETED Phase 1 16 participants

Ready to Use Therapeutic Food (RUTF) to Promote Growth in Cystic Fibrosis

Washington University School of Medicine

NCT03462056

COMPLETED Phase 2 16 participants

Nasally Delivered Pulmozyme for Sinusitis in Cystic Fibrosis

University of Vermont

NCT00416182

COMPLETED Phase 1 16 participants

Pharmacokinetics and Safety Assessment of VX-121/Tezacaftor/Deutivacaftor in Participants With Moderate Hepatic Impairment

Vertex Pharmaceuticals Incorporated

NCT05437120

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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.