PREterm Infants With Bronchial Obstruction - Prospective Study of Efficacy and Safety of Inhaled Tiotropium

This clinical trial is designed as an investigator-initiated, academic, phase IV, randomized, open-label, 2x2 crossover study to evaluate the response to inhaled tiotropium bromide in children and adolescents born prematurely who suffer from chronic bronchial obstruction.

The study consists of two different sequences:

• Sequence A (Treatment first): Participants receive inhaled tiotropium (5 µg once daily via Spiriva Respimat) for 3 months, followed by a 4-week washout period, and subsequently undergo a 3-month control observation period under standard treatment.
• Sequence B (Control first): Participants start with a 3-month control observation period under standard treatment, followed immediately (without a washout period) by a 3-month treatment period with daily inhaled tiotropium.

Clinical and spirometric assessments (including Forced Expiratory Volume in 1 second in liters - FEV₁, Forced Vital Capacity in liters - FVC, Peak Expiratory Flow in liters per second - PEF, Forced Expiratory Flow between 25% and 75% of FVC in liters per second - FEF₂₅-₇₅ parameters) will be performed at baseline, at the crossover point (end of the first period), and at the end of the study (end of the second period). Participants or their parents will maintain daily diaries to log respiratory symptoms, rescue medication - short-acting beta₂-agonist (SABA) use, and potential acute exacerbations throughout the trial.

Inclusion criteria

• Age between 6 and 18 years.
• History of preterm birth (defined as delivery at < 37 gestational weeks).
• Spirometrically proven bronchial obstruction, defined as a z-score of FEV1 and/or >= 2 other parameters - Forced Vital Capacity (FVC; liters [L]), Peak Expiratory Flow (PEF; liters per second [L/s]), and Forced Expiratory Flow between 25% and 75% of Forced Vital Capacity (FEF25-75; liters per second [L/s]).) below -1.65 SD.
• Positive bronchodilatation test, defined as an increase in FEV₁ or FVC of more than 10% of the corresponding GLI-predicted value following administration of ipratropium bromide. Bronchodilator responsiveness will be calculated separately for FEV₁ and FVC as:

[(post-bronchodilator value - pre-bronchodilator value) / predicted value] × 100.

FEV₁ and FVC will be measured in litres (L) after ipratropium administration.

• Acceptable spirometry performance in accordance with American Thoracic Society/European Respiratory Society (ATS/ERS) 2019 standards.
• No long-term inhalation therapy (such as a long-acting beta₂-agonist (LABA) or a combination of an inhaled corticosteroid and a long-acting beta₂-agonist (ICS/LABA)) within the last month prior to study enrollment.

Exclusion criteria

• Other chronic respiratory diseases (e.g., asthma, cystic fibrosis).
• Anatomical abnormalities of the respiratory tract or presence of glaucoma.
• Congenital malformations of the uropoetic tract or cardiac arrhythmias/congenital heart defects.
• Concomitant use of anticholinergic medications for enuresis nocturna.
• Pregnancy (mandatory urine screening required for all female participants aged 13 years and older).
• Insufficient cooperation or inability to properly perform spirometry maneuvers.