Abstract Rationale Climate change is a major health threat; the World Health Organization estimates it could cause 250,000 additional deaths annually between 2030-2050.1 Most SABAs are delivered via pressurized metered-dose inhalers (MDIs) containing a propellant, hydrofluoroalkane (HFA)-134a, a greenhouse gas with a 100-year global warming potential (GWP) 1530 times higher than CO2.2 A new propellant, HFA-152a, is approximately 10 times less impactful on the environment than HFA-134a,2 offering a more sustainable option for MDIs. A salbutamol MDI with HFA-152a is in development, showing 90% lower carbon emissions3 and therapeutic equivalence to the HFA-134a formulation.4,5 This study assessed the safety and tolerability of 3 months’ treatment with salbutamol MDI with HFA-152a compared with HFA-134a. Methods This was a Phase 3, randomized, double-blind, parallel-group, multicenter study (NCT06261957). Adults (≥18 years) with asthma receiving a stable dose of ICS, ICS/LABA, ICS/LABA/LAMA, or SABA only for ≥12 weeks prior to screening, with a baseline pre-bronchodilator FEV1 ≥60% predicted, and Asthma Control Questionnaire-6 score 1.5 were enrolled. Participants were randomized 3:1 to receive salbutamol MDI with HFA-152a or HFA-134a for 12 weeks, taking ≥2 x 100mcg actuations once daily, plus as-needed for symptoms, not exceeding 800mcg/day. Incidence of adverse events (AEs; primary endpoint) and serious AEs (SAEs; a secondary endpoint) were assessed. Additional safety parameters included laboratory values, vital signs and ECG assessments at each visit. Results There were 450 participants in the safety analysis set; 338 received salbutamol MDI with HFA-152a (mean SD daily dose: 223.465.50mcg) and 112 received salbutamol MDI with HFA-134a (220.777.25mcg). AEs were experienced by 32% of participants in both treatment groups (HFA-152a, n = 108; HFA-134a, n = 36); 1% were treatment-related in each group. SAEs were experienced by 2% of participants receiving HFA-152a (n = 6) and 3% receiving HFA-134a (n = 3), all non-fatal (Table). The additional safety parameters assessed were also comparable. Conclusions The safety profile of salbutamol MDI with HFA-152a was comparable, and consistent with the current salbutamol MDI with HFA-134a, providing further evidence of therapeutic equivalence. These findings support the development of the low-GWP salbutamol MDI with propellant HFA-152a. References 1. World Health Organization. Fact sheet: Climate change. 2023. Available from: https://www.who.int/news-room/fact-sheets/detail/climate-change-and-health accessed October 15, 2025 2. Greenhouse Gas Protocol. IPCC Global Warming Potential Values 2024. Available from: https://ghgprotocol.org/sites/default/files/2024-08/Global-Warming-Potential-Values%20%28August%202024%29.pdf accessed October 15, 2025 3. Plank M, et al. Am J Respir Crit Care Med. 2025;211:A5548 4. Janson C, et al. Eur Respir J. 2025:OA3298 5. Singh D, et al. Eur Respir J. 2025:PA339 This abstract is funded by: GSK (study ID: 220735)
Weinberg et al. (Fri,) studied this question.