A Study Testing the Superiority of CHF 1535 pMDI 800/24µg Total Daily Dose Compared With CHF 718 pMDI 800µg Total Daily Dose in Adults With Asthma on Medium or High-Dose Inhaled Corticosteroid

Compare the superiority of CHF 1535 versus CHF 718 in subjects with asthma who are on medium or high dose inhaled corticosteroids.

Inclusion Criteria (IC): 1. Informed consent: A signed and dated written informed consent obtained prior to any study-related procedures. 2. Sex and age: Male or female aged ≥18 and ≤75 years. 3. Diagnosis of asthma: A documented history of asthma for at least 1 year, with onset before age 40 4. Stable asthma therapy: Use of medium-dose ICS with or without a LABA or high-dose ICS alone for 3 months (at a stable dose for at least 4 weeks prior to screening). 5. Lung function: Subjects with a pre-bronchodilator FEV1 ≥40% and ≤85% of predicted, after appropriate washout from bronchodilators, at the screening and randomization visits. In addition, the absolute value of the first pre-dose FEV1 at randomization (V2) must be at least 80% of the pre-bronchodilator value attained at screening. 6. Reversibility post-bronchodilator: Subjects with a positive reversibility to bronchodilator at screening, defined as an increase in FEV1 \> 12% and \> 200mL compared to baseline within 30 minutes after 4 inhalations of albuterol hydrofluoroalkane (HFA) pMDI 90µg/actuation. Note for IC#5 and IC#6: In case the reversibility and/or quality threshold is not met at screening, the test can be performed once before randomization. 7. Female subjects: a. Women of childbearing potential (WOCBP) fulfilling one of the following criteria: i. WOCBP with fertile male partners: they and/or their partner must be willing to use a highly effective birth control method from the signing of the informed consent form and until the follow-up contact or ii. WOCBP with non-fertile male partners (contraception is not required in this case). b. Female subjects of non-childbearing potential defined as physiologically incapable of becoming pregnant (i.e. post-menopausal or permanently sterile as per definitions given in Appendix 2). Tubal ligation or partial surgical interventions are not acceptable. If indicated, as per investigator's request, post-menopausal status may be confirmed by follicle-stimulating hormone levels (according to local laboratory ranges). 8. Cooperative attitude and ability to demonstrate correct use of the pMDI inhalers and eDiary/peak flow meter. Exclusion Criteria: 1. Pregnancy or lactation: where pregnancy is defined as the state of a female after conception and until termination of the gestation, confirmed by a positive pregnancy test (serum and urine pregnancy test to be performed at screening visit and urine pregnancy test to be performed prior to randomization). 2. Poor compliance with run-in medication or eDiary completion \