This clinical study aims to test a new drug, **DA-1229 (Evogliptin)**, for people with a heart condition called **calcific aortic valve disease** and **mild to moderate aortic stenosis**. Aortic stenosis is when the aortic valve in the heart becomes narrow. The study will last for **112 weeks** with three main phases: a **Screening Period** (up to 4 weeks), a **Treatment Period** (104 weeks), and a **Follow-Up Period** (2-4 weeks). Participants will be randomly placed into two groups: one receiving DA-1229 and the other a placebo (a harmless pill with no medicine). **Key Points:** - Includes taking a pill daily for **104 weeks**. - **Eligibility**: Adults aged 35 or older with specific heart conditions. - Participants can withdraw anytime, and some medical conditions may disqualify someone from participating. Before joining, make sure to discuss with your doctor, especially if you have other health concerns or are taking medications.