A Clinical Study of MK-4208/TERN-701 in Participants With Chronic Myeloid Leukemia (CML) (MK-4208-003/Tern701-1012/CARDINAL)

Researchers are looking for a new way to treat a blood cancer called chronic myeloid leukemia (CML). Researchers want to learn if MK-4208 (Tern-701) can treat this type of blood cancer. The goal of this study is to learn about the safety of different doses (amounts) of MK-4208 (Tern-701) and if people tolerate them. Researchers also want to find the highest dose of MK-4208 (Tern-701) that people can tolerate and may work to treat blood cancer.

Key Inclusion Criteria: Inclusion Criteria include but are not limited to: * Have an Eastern Cooperative Oncology Group (ECOG) performance status score of 0 to 2 * Have an established cytopathologically confirmed diagnosis of breakpoint cluster region::Abelson (BCR-ABL1) positive Chronic Myeloid Leukemia (CML) in Chronic Phase * Have received treatment with at least one prior tyrosine kinase inhibitor (TKI) and have treatment failure, suboptimal response, or treatment intolerance * Prior treatment with asciminib is allowed * Adequate organ function, as assessed by local laboratory Key Exclusion Criteria: Exclusion criteria include but are not limited to: * Systemic antineoplastic therapy (including prior TKIs, interferon-alfa, therapeutic antibodies, chemotherapy) or other experimental therapy 7 days before the first dose of MK-4208/TERN-701 * Have completed previous anticancer therapy without resolution of all associated clinically significant toxicity (to ≤ Grade 2 or baseline)