MCC THERAPEUTICS, INC. WILL PRESENT PHASE I TRIAL OF ITS INHALED SYNERGISTIC COMBINATION, MCCSA2, OF ADRENERGIC AND CHOLINERGIC AGONISTS TO ENHANCE MUCOCILIARY CLEARANCE IN CYSTIC FIBROSIS AT THE EUROPEAN RESPIRATORY SOCIETY CONGRESS IN BARCELONA, SPAIN

MCC Therapeutics will be presenting expanded results of a Phase 1, single ascending dose (SAD) study in healthy volunteers (HV) and patients with cystic fibrosis (pwCF) treated with inhaled MCCSA2, a combination of Formoterol and Methacholine at the European Respiratory Society (ERS) held in Barcelona, Spain, September 5- 9, 2026. The results are presented in the Targeting Complex Airway Disease Phenotypes session.

Mucociliary clearance (MCC), mediated by the actions of diverse conducting airway and submucosal gland epithelial cells, plays a critical role in a multilayered defense system by secreting fluids, electrolytes, antimicrobial and anti-inflammatory proteins, and mucus onto airway surfaces. Although mucus and other airway epithelial secretions play a critical role in protecting the lung during acute injury, impaired mucus clearance after chronic mucus hyperproduction causes airway obstruction and infection, which contributes to morbidity in common pulmonary disorders, including bronchiectasis, COPD, asthma, cystic fibrosis, and primary ciliary dyskinesia. We conducted a SAD study in healthy volunteers (HC) and patients with cystic fibrosis (pwCF). We tested a fixed nebulized dose of formoterol 20μg or formoterol 20μg in combination with 1μg, 3μg or 12μg of methacholine (MCCSA2), administered simultaneously, in twelve (n=12) HV followed by twenty-four (n=24) pwCF, with hetero or homozygous F508del mutation, treated with highly effective modulator therapy (HEMT, Trikafta). At baseline, no significant differences in spirometry were observed between HV and pwCF. A significant difference in lung clearance index (LCI) was observed at baseline between HV and pwCF, reflecting the presence of active sub clinical airway disease despite HEMT. In addition, all pwCF had bronchiectasis and a significant proportion were experiencing daily symptoms and exacerbations. Following the administration of MCCSA2 no adverse events or signs of intolerance were noted up to 2 hours following dosing in both HV and pwCF. Mild improvement in FEV1 was observed in both HV and pwCF. Despite the small number of subjects, positive trends for acute increases in lung function were noted (FEV1/FVC ratio and FEF25%-75%). All treatment groups produced sputum and with a trend in pwCF for larger amounts with the highest MCCSA2 dose and a significantly higher solids content. A single dose of MCCSA2 was safe in HV and pwCF. Early signals of efficacy in MCC function are detected with a single dose.

“Following our extensive pre-clinical work, including several in vivo models, recently published in JCI, these results resolve some of the uncertainties regarding the effects in the airway and tolerability of MCCSA2 and speak of their great potential to alleviate mucus obstruction.” Said Dr. Carlos Milla, Stanford University and co-founder of MCC Therapeutics. “Since we demonstrated that the synergistic effect of MCCSA2 is effective at restoring MCC in a CFTR independent manner, the combined outcomes of the study provide solid basis for the application of the two drugs in muco-obstructive lung diseases. It is important to remember that mucus accumulation continues to be an unmet need for these patients”.

“MCC Therapeutics, Inc. is excited about the clinical data from this Phase 1 study”, said Dr. Isaac Cohen, MCC Therapeutics’ CEO. “To reduce current treatment burden patients with muco-obstructive diseases face, we developed a dry powder inhaled formulation with improved drug deposition. This will ensure higher compliance and reduce treatment burden for our patients”.
MCC Therapeutics is planning to launch a Phase 1 single ascending dose, followed by a multiple ascending dose clinical trial in bronchiectasis (NCFB) patients. The trial is planned to start early 2027.

Forward Looking Statements
This release contains certain forward-looking statements relating to the business of MCC Therapeutics, Inc. that can be identified by the use of forward-looking terminology such as “believes,” “expects,” or similar expressions. Such forward-looking statements involve known and unknown risks and uncertainties, including uncertainties relating to product development, efficacy and safety, regulatory actions or delays, the ability to obtain or maintain patent or other proprietary intellectual property protection, market acceptance, physician acceptance, third party reimbursement, future capital requirements, competition in general and other factors that may cause actual results to be materially different from those described herein as anticipated, believed, estimated or expected. MCC Therapeutics, Inc. is under no obligation (and expressly disclaims any such obligation) to update or alter its forward-looking statements whether as a result of new information, future events or otherwise.