AstraZeneca has completed a phase 3b clinical study evaluating the safety of HFO MDI compared to HFA MDI propellants in asthma patients, while simultaneously launching an observational study in China to assess biologic treatment patterns. The completed study, titled "Randomized, DB, Crossover Study to Assess Bronchospasm Potentially Induced by HFO MDI vs. HFA MDI Propellant in Participants With Asthma Well/Partially Controlled on SABA With or Without Low-Dose ICS," aimed to evaluate safety and tolerability differences between the two inhaler propellant systems.
Completed HFO MDI Safety Study
The interventional study employed a randomized, double-blind crossover design to compare HFO MDI as the experimental treatment against HFA MDI as the reference. Both interventions were administered as four inhalations per dose, with the primary focus on assessing changes in lung function and bronchospasm events in asthma patients whose condition was well or partially controlled on short-acting beta agonists (SABA) with or without low-dose inhaled corticosteroids (ICS).
The study maintained blinding for participants, care providers, and investigators throughout the treatment allocations. Beginning on May 2, 2023, the study reached completion with results first submitted on August 19, 2024, and the most recent update submitted on July 29, 2025.
China Observational Study Launch
Concurrently, AstraZeneca initiated an observational, prospective, multicenter study titled "An Observational, Prospective, Multicenter Study to Evaluate the Biologic Use and Outcomes in Chinese Asthma Patients." This study launched on November 14, 2024, and aims to assess the use of biologics and clinical outcomes in asthma patients across China.
The observational study follows a case-only model with a prospective time perspective, enrolling approximately 200 patients who will receive standard medical care as determined by their physicians. The study does not involve experimental treatments but focuses on observing patients already prescribed asthma biologics. Patients will be followed through three key visits over one year, with data collected from existing medical records and patient-reported outcomes.
Market Implications
The completion of the HFO MDI study could potentially lead to the introduction of a new asthma treatment option, enhancing AstraZeneca's competitive position in the respiratory market. The outcomes may influence the company's stock performance by demonstrating the safety profile of HFO MDI technology compared to traditional HFA propellants.
The China observational study addresses a significant market opportunity, as it will provide insights into the effectiveness of biologics in asthma treatment within China, representing a key demographic for respiratory therapeutics. The study's findings could impact investor sentiment positively, considering the growing global demand for effective asthma treatments.
Both studies are currently recruiting or have completed enrollment, with the China study's primary completion and estimated overall completion dates yet to be announced. The latest update for the China study was submitted on June 30, 2025, indicating ongoing recruitment and data collection activities.
