A Phase IIa, Randomized, Double-Blind, Placebo-Controlled Trial of JKN2403 in COPD

The goal of this clinical trial is to learn if drug JKN2403 works to treat moderate-to-severe COPD in adults. It will also learn about the safety and pharmacokinetic characteristics of drug JKN2403. The main questions it aims to answer are: Does drug JKN2403 reduce the incidence of AECOPD or improve the quality of life or alleviate symptoms related to COPD? Researchers will compare drug JKN2403 to a placebo (a look-alike substance that contains no drug) to see if drug JKN2403 works to treat moderate-to-severe COPD. Participants will: Take drug JKN2403 or a placebo every day for 24 weeks Visit the clinic once every four weeks for checkups and tests Keep a diary of their symptoms and the number of times they use a rescue inhaler