Ensifentrine for decreasing the frequency/severity of COPD exacerbations

A method of treating chronic obstructive pulmonary disease (COPD) in a human subject suffering from COPD who has experienced an exacerbation of COPD, wherein the exacerbation of COPD is a temporary worsening of one or more symptoms of COPD suffered by the human subject lasting at least two consecutive days, the method comprising administering to the human subject via inhalation two or more doses per day of a composition comprising a therapeutically effective amount of ensifentrine or a pharmaceutically acceptable salt thereof, wherein a frequency of the exacerbation of COPD is reduced by at least 40% compared to the frequency of the exacerbation of COPD in an untreated human subject having COPD and not administered the composition, wherein the subject has FEV1 prior to said administering from 30% to 70%, the exacerbation is (a) worsening of 2 or more major symptoms selected from the group consisting of dyspnea, sputum volume, and sputum purulence or (b) worsening of any 1 major symptom selected from the group consisting of dyspnea, sputum volume, and sputum purulence together with a minor symptom selected from the group consisting of sore throat, colds, fever without other cause, and increased cough or wheeze for at least 2 consecutive days, and the therapeutically effective amount of the ensifentrine or the pharmaceutically acceptable salt thereof is 2 mg to 4 mg and wherein the composition is a suspension comprising:

• a. ensifentrine particles at a concentration of from 1 to 1.4 mg/ml;
• b. polysorbate 20 at a concentration of from 0.3 to 0.7 mg/ml;
• c. sorbitan monolaurate at a concentration of from 0 to 0.1 mg/ml;
• d. sodium dihydrogen phosphate dihydrate at a concentration of from 0.5 to 1 mg/mL;
• e. disodium hydrogen phosphate dihydrate at a concentration of from 0.5 to 1 mg/mL;
• f. sodium chloride at a concentration of 5 to 10 mg/mL;
• and
• g. water.