This first-in-human trial with ELVN-001 is a dose escalation study with the primary purpose to identify the recommended dose(s) for expansion (RDEs) of single agent ELVN-001 in chronic phase CML with or without T315I mutations. The safety, tolerability and pharmacokinetic profile of ELVN-001 will be assessed together with an evaluation of changes in BCR-ABL1 transcript. An understanding of the safety profile, PK and preliminary evidence of anti-CML activity will be used to inform future development of ELVN-001 in adults with CML. By virtue of its predicted pharmacological profile ELVN-001 has the potential to be tolerable and achieve a deep molecular response in patients with CML with or without T315I mutations who do not tolerate or benefit from available TKIs.