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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 4 of 4

COMPLETED Phase 2 16 participants

Effect of Lucinactant on Mucus Clearance in Cystic Fibrosis Lung Disease

University of North Carolina, Chapel Hill

NCT00934362

COMPLETED Phase 4 15 participants

PR-018: An Open-Label, Safety Extension of Study PR-011

Forest Laboratories

NCT01131507

COMPLETED Phase 3 15 participants

SIMPLICITY: Studying Impacts on Malabsorption With Liprotamase in Cystic Fibrosis

Anthera Pharmaceuticals

NCT02734810

COMPLETED 14 participants

Exercise-Induced Bronchospasm in Cystic Fibrosis

Ohio State University

NCT00806455

COMPLETED 14 participants

IL-17 Neutrophils in CF Lung Inflammation

University Hospitals Cleveland Medical Center

NCT02025829

COMPLETED NA 12 participants

The Impact of Patch Rx Technologies on Adherence to Vitamin and Trikafta Therapies in Patients With Cystic Fibrosis

The University of Texas Health Science Center at San Antonio

NCT04684823

COMPLETED Phase 1 12 participants

Effects of Inhaled Bicarbonate on Airway pH in Cystic Fibrosis

Joseph Pilewski

NCT03391414

COMPLETED Phase 4 11 participants

Pharmacokinetics of Tedizolid Phosphate in Cystic Fibrosis

University of Southern California

NCT02444234

COMPLETED NA 11 participants

A Pilot Study of a Low Glycemic Load Diet in Adults With Cystic Fibrosis

Boston Children's Hospital

NCT04519853

COMPLETED Phase 1 11 participants

Safety Study of Orally Administered Curcuminoids in Adult Subjects With Cystic Fibrosis

Ramsey, Bonnie, MD

NCT00219882

COMPLETED Phase 1 10 participants

Clearance of 25-hydroxyvitamin D in Cystic Fibrosis

University of Washington

NCT03104855

COMPLETED Phase 1 10 participants

Flaxseed Modulates Inflammation and Oxidative Stress in CF

University of Pennsylvania

NCT02014181

COMPLETED Phase 2 9 participants

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of QAU145 in Patients With Cystic Fibrosis

Novartis Pharmaceuticals

NCT00506792

COMPLETED Phase 4 9 participants

Malabsorption Blood Test:Toward a Novel Approach to Quantify Steatorrhea

Children's Hospital of Philadelphia

NCT00572975

COMPLETED Phase 1 9 participants

SD Cystic Fibrosis Study

GlaxoSmithKline

NCT00605761

COMPLETED 8 participants

Clinical Outcomes of Triple Combination Therapy in Severe Cystic Fibrosis Disease.

National Jewish Health

NCT04038710

COMPLETED Phase 4 8 participants

Pharmacokinetic and Pharmacodynamic Analysis of Ceftaroline in Children and Adolescents With Cystic Fibrosis

Children's Hospital Medical Center, Cincinnati

NCT03771313

COMPLETED Phase 1 6 participants

PK Study of N91115 in Cystic Fibrosis Patients

Nivalis Therapeutics

NCT02227888

COMPLETED Phase 1 6 participants

Treatment of Dysglycemia Using Sitagliptin in Adolescents With Cystic Fibrosis

Nemours Children's Clinic

NCT01721382

COMPLETED Phase 4 1 participants

Evaluation of Ivacaftor in Patients Using Ataluren for Nonsense Mutations

University of Alabama at Birmingham

NCT03256799

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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.