Early Study on Tamoxifen Safety/Tolerability in Cystic Fibrosis Patients Unable to Use CFTR Modulators.

NCT07289035 | Not Yet Recruiting Phase 2

• 2 other identifiers: CRCFC-TAMOXI0632024-519657-11-00
• Study Type: interventional
• Target: 35
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to evaluate the safety and tolerability of TMX in adults patients with cystic fibrosis who do not have mutations currently eligible for therapy with modulator drugs. The main questions it aims to answer is: . What medical problems do participants have when taking drug TMX? Participants will:

• Take drug TMX every day for 6 months
• Visit the clinic once every 28 days for checkups and tests

Conditions

Cystic Fibrosis - Complete

Keywords

Cystic Fibrosis; Tamoxifen; CaCC

Outcome Measures

Primary Outcomes (1)

• Number of participants with treatment-related adverse events as assessed by CTCAE v4.0

  The primary endpoint of this study will be evaluated by calculating between baseline and week 24 the incidence of serious adverse events (SAEs), treatment-emergent adverse events (TEAEs) and treatment discontinuation due to AEs. In addition, frequency of specific, indication-relevant adverse events (e.g., thromboembolic events, elevation of liver enzymes, pulmonary exacerbations) and cumulative AE analyses, such as the number of AEs per patient, will be also evaluated.

  Calculating between baseline and week 24

Secondary Outcomes (8)

• Changes in respiratory function values

  From baseline to week 24

• Changes in pulmonary exacerbation

  Up to week 24

• Changes in hospitalizations

  From baseline to week 24

• Changes in quality of life

  From baseline to week 24

• Changes in antibiotic use

  Up to week 24

Study Arms (1)

Tamoxifen citrate

EXPERIMENTAL

Patients will receive TMX 20 mg/day, in the morning. The choice of this dosage is based on pharmacokinetic and pharmacodynamic data in the literature in patients with breast cancer. Based on this scientific evidence, the dose of 20 mg/day is the minimum dose to ensure safety and efficacy of treatment. Women should start treatment with TMX between 8 and 12 days after the onset of menstruation. A longer screening period to allow for this timing will not be considered a protocol violation. Men will start treatment at V2 (day 1) and continue at home for 24 weeks. After screening, visits will be performed on the first day of TMX administration (baseline) and after 4, 8, 12, 16, and 24 weeks. Patients will discontinue TMX treatment at week 24 and will be followed for an additional 4 weeks for safety evaluation.

Drug: Tamoxifen Citrate 20Mg Tab

Interventions

Tamoxifen Citrate 20Mg Tab DRUG

One tablet per day (20 mg/day), in the morning.

Also known as: TMX

Tamoxifen citrate

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Subjects of both sexes, affected by cystic fibrosis, attending the CF Center in Verona
• Patients who do not have mutations currently eligible for therapy with CFTR modulator drugs
• Age 18 years or older
• Predicted forced expiratory volume in 1 second (ppFEV1) ≥ 40% and ≤ 90% (of the predicted value for people of their age, sex, and height) before bronchodilator administration
• Stable routine CF therapy in terms of dose and medication (inhaled antibiotic cycles, bronchodilator, anti-inflammatory, inhaled corticosteroid, physiotherapy technique/schedule) within 28 days prior to Day 1
• Clinically stable respiratory disease within 3 weeks before Day 1 (first dose of study drug)
• Subjects able to perform reliable and reproducible pulmonary function test maneuvers
• Subjects able to communicate well with the investigator, understand, and comply with the study requirements
• Female subjects must have a negative serum pregnancy test
• Sexually active subjects able to follow the contraceptive methods defined within the protocol (non-hormonal contraception) during the study and for 2 months after study discontinuation
• Signed informed consent for participation in the study and for the processing of personal data.

You may not qualify if:

• Patients will be excluded if one or more of the following criteria are met at Visit 1:
• Patients on any CFTR modulator therapy
• Pulmonary exacerbations within 3 weeks before Day 1 (first dose of study drug)
• Changes in therapy for lung disease within 3 weeks before Day 1 (first dose of study drug)
• Family and/or personal history of thromboembolism and thromboembolic conditions up to 1st-degree relatives
• Documented hereditary thrombophilia (hypercoagulability), e.g., protein C, protein S, and antithrombin deficiency; factor V G169A Leiden, prothrombin G20210A (PT20210A), elevated factor VIII levels, hereditary dysfibrinogenemia
• History of solid organ or hematopoietic transplant
• History of hypersensitivity to the study drug or drugs of similar chemical classes or any excipients
• History or presence of prolonged QT interval (QTcB \> 450 msec)
• History of malignancy in any organ system (other than localized basal cell carcinoma of the skin) in the last 5 years
• Hemoglobin levels \< 9.0 g/dl
• Any surgical or medical condition that may significantly alter the absorption, distribution, metabolism, or excretion of drugs, or that may jeopardize the subject in case of participation in the study
• History of immunodeficiency diseases
• History of drug or alcohol abuse
• History of any disease or condition that, in the investigator's opinion, could confound the study results

Sponsors & Collaborators

• Azienda Ospedaliera Universitaria Integrata Verona: lead

Study Sites (1)

UOC Fibrosi Cistica - AOUI Verona

Verona, Veneto, 37126, Italy

Location

MeSH Terms

Conditions

Cystic Fibrosis

Interventions

Tamoxifen

Condition Hierarchy (Ancestors)

Pancreatic Diseases; Digestive System Diseases; Lung Diseases; Respiratory Tract Diseases; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Infant, Newborn, Diseases

Intervention Hierarchy (Ancestors)

Stilbenes; Benzylidene Compounds; Benzene Derivatives; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Hydrocarbons; Organic Chemicals

Central Study Contacts

Marco Cipolli, MD

CONTACT

+390458122293; marco.cipolli@aovr.veneto.it

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 20, 2025
• First Posted: December 17, 2025
• Study Start: January 15, 2026
• Primary Completion: April 1, 2026
• Study Completion (Estimated): February 1, 2027
• Last Updated: December 17, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

IT (1)