This study tests a new drug called asciminib for people with Chronic Myeloid Leukemia in Chronic Phase (CML-CP), a type of blood cancer. Asciminib is taken by mouth once a day. The study checks if the drug works using a blood test called PCR. If after 2-3 years asciminib alone doesn't work well, a low dose of other drugs (dasatinib, imatinib, or nilotinib) may be added. These drugs help stop cancer cells from growing. The study lasts about 5 years, and up to 8 years if aiming for no treatment. Enrollment is for people at least 18 years old, newly diagnosed with CML-CP, and meeting other health requirements.

• The study lasts about 5-8 years.
• Asciminib is taken once daily, possibly with other drugs later.
• Participants will have regular blood tests to check the drug's effect.