This study is looking at a new medicine called KRT-232 for treating a type of blood cancer known as Chronic Myeloid Leukemia (CML). CML happens when the body makes too many white blood cells. The study is for people whose CML has come back or doesn't respond well to other treatments called Tyrosine Kinase Inhibitors (TKIs). KRT-232 is a pill that blocks a protein called MDM2 to help stop the cancer from growing. This study is in two phases, Phase 1b and Phase 2, and is being done in different countries to see how well KRT-232 works and if it's safe.

Key Points:

• The study is open to adults 18 and older with certain types of CML who didn't do well with TKI treatment.
• Participants need to have good liver, kidney, and blood health to join.
• People who have had certain other treatments or mutations cannot join the study.