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Investigational gene therapy for adults with cystic fibrosis

An Open-label, Phase 1/2 Trial of Gene Therapy 4D-710 in Adults With Cystic Fibrosis

Phase 2 Interventional 4D Molecular Therapeutics · NCT05248230

This study is testing a new gene therapy for adults with cystic fibrosis who have severe lung disease and can't use current treatments, to see if it helps improve their health.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment30 (estimated)
Ages18 Years and up
SexAll
Sponsor4D Molecular Therapeutics Industry-sponsored
Locations20 sites (Birmingham, Alabama and 19 other locations)
Trial IDNCT05248230 on ClinicalTrials.gov

What this trial studies

This Phase 1/2 trial evaluates the safety, tolerability, and preliminary efficacy of 4D-710, an investigational gene therapy, in adults with cystic fibrosis who have advanced lung disease and are ineligible or unable to tolerate CFTR modulator therapy. The study includes a sub-study for those currently on CFTR modulator therapy experiencing frequent pulmonary exacerbations. Participants will receive a single dose of 4D-710, and the trial will assess various health outcomes related to cystic fibrosis lung disease.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older with confirmed cystic fibrosis and advanced lung disease who are ineligible for or have discontinued CFTR modulator therapy.

Not a fit: Patients with mild cystic fibrosis or those who are currently well-managed on CFTR modulator therapy may not benefit from this study.

Why it matters

Potential benefit: If successful, this therapy could provide a new treatment option for adults with cystic fibrosis who cannot tolerate existing therapies.

How similar studies have performed: Other studies have shown promise with gene therapy approaches for cystic fibrosis, but this specific investigational therapy is novel.

Eligibility criteria

Show full inclusion / exclusion criteria 
Key Inclusion Criteria (Primary Study):

1. 18 years and older
2. Confirmed diagnosis of cystic fibrosis (CF) and CF lung disease including:

   1. Sweat chloride ≥ 60 mmol/L
   2. Mutation Status

      * Bi-allelic mutations in the CFTR gene, or
      * Single mutation in the CFTR gene and clinical manifestations of CF lung disease
   3. Ineligible for CFTR modulator therapy, or previously received modulator therapy but discontinued due to adverse effects.
3. Forced expiratory volume in 1 second (FEV1) ≥ 50% and ≤ 90% of predicted (per Global Lung Function Initiative) at Screening
4. Resting oxygen saturation ≥ 92% on room air at Screening

Key Inclusion Criteria (Sub-Study):

1. 18 years and older
2. Confirmed diagnosis of cystic fibrosis (CF) and CF lung disease including:

   1. Sweat chloride ≥ 60 mmol/L
   2. Mutation Status

      * Bi-allelic mutations in the CFTR gene, or
      * Single mutation in the CFTR gene and clinical manifestations of CF lung disease
3. Currently on a stable dose of CFTR modulator therapy for a minimum of 60 days prior to Screening and agree to maintain current regimen through the 24-month Observation Period
4. FEV1 ≥ 40% and \< 70% predicted (per Global Lung Function Initiative) at Screening, AND/OR experienced at least 2 pulmonary exacerbations in the last year requiring intravenous antibiotics

Key Exclusion Criteria (Primary and Sub Study):

1. Any prior gene therapy for any indication (Exception: mRNA-based or antisense oligonucleotide therapies are not exclusionary)
2. Active Mycobacterium abscessus infection requiring ongoing treatment at Screening
3. Active allergic bronchopulmonary aspergillosis requiring management with systemic corticosteroids or antifungal therapy
4. Smoking (e.g. cigarettes, cigars, cannabis) or use of a vaping product during the 2 months prior to screening; must agree to not smoke or use vaping products during Screening and initial 24-month observation period.
5. Contraindication to systemic corticosteroid therapy
6. Requires chronic use of systemic corticosteroids or immunosuppressants to treat another condition
7. If no known diagnosis of cystic fibrosis related diabetes (CFRD), Type I, or Type II diabetes: Hemoglobin A1C ≥ 6.5% at Screening
8. If known diagnosis of CFRD, Type I or Type II diabetes: Hemoglobin A1C \> 7.5% at Screening
9. Recent history of symptomatic hyperglycemia or unstable blood glucose levels as per Investigator's assessment
10. Other conditions that, in the Investigator's opinion, may interfere with management of corticosteroid-related hyperglycemia
11. Body Mass Index (BMI) \< 16
12. Laboratory abnormalities at screening:

    * ALT, AST or GGT ≥ 3 × the upper limit of normal (ULN)
    * Total bilirubin ≥ 2 × ULN
    * Hemoglobin \< 10 g/dL
13. Requirement for continuous or night-time oxygen supplementation
14. Known CF liver disease with evidence of multilobular cirrhosis
15. History of thrombosis (excluding catheter-related thrombosis) or conditions associated with increased risk of thrombosis

Where this trial is running

Birmingham, Alabama and 19 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Cystic Fibrosis LungCFCystic FibrosisGene Therapy
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.