This clinical trial is focused on studying the safety of a treatment for people with asthma, a condition that affects the airways in the lungs and can cause breathing difficulties. The study will compare two formulations of a medication known by the code name CHF5993. This medication is a combination of three active substances: glycopyrronium bromide, formoterol fumarate dihydrate, and beclometasone dipropionate anhydrous. These substances work together to help open the airways and reduce inflammation, making it easier to breathe. The trial will also use salbutamol as a rescue medication, which is commonly used to quickly relieve asthma symptoms.

The purpose of the study is to evaluate the safety of the two formulations of CHF5993 in people with moderate to severe asthma. Participants will be randomly assigned to one of two groups, each receiving a different formulation of the medication. The study will last for 12 weeks, during which participants will use an inhaler to take their assigned medication. Throughout the study, participants will have regular visits to monitor their health and assess how their lungs are functioning. The study is designed to be double-blind, meaning neither the participants nor the researchers will know which formulation each participant is receiving, to ensure unbiased results.

Participants will be asked to use an electronic diary to record their symptoms and any use of the rescue medication, salbutamol. The study aims to provide valuable information on the safety of the new formulation of CHF5993 and its potential to help people with asthma manage their condition more effectively. The trial will help determine if the new formulation is as safe as the existing one, with a focus on any potential for causing bronchoconstriction, which is a narrowing of the airways that can make breathing difficult.