A Study of Full Treatment-free Remission in Patients With Chronic Myeloid Leukemia

This is a prospective, single arm, phase II study constituted of two stage: Treatment-Free Remission 1 (TFR1) stage and Treatment-Free Remission 2 (TFR2) stage.

The TFR1 stage is made up of 4 periods:

1. Screening (week -4 - week 0) 2. Nilotinib consolidation (week 0 - week 48): Patients will be treated with nilotinib 300 mg QD. At the end or during the consolidation period, patients will proceed as follows:

* Patients with sustained DMR at the end of the consolidation phase will enter the treatment-free remission (TFR1) and nilotinib will be discontinued. If two or more consecutive quarterly BCR-ABL RQ-PCR assessments are not performed or results are not available, the patient will not be eligible for TFR1 period and will be treated with nilotinib 300 mg QD until the end of the TFR1 stage (week 144). * Patients with loss of major molecular response (MMR) at any time during the consolidation phase will enter the follow-up period and will return to the standard nilotinib administration regimen (nilotinib 300 mg BID) until the end of the TFR1 stage (week 144). * Patients with more than MMR, but without meeting the definition of sustained DMR, will remain in the consolidation phase and will be treated with nilotinib 300 mg QD until the end of the TFR1 stage (week 144). 3. Nilotinib treatment-free remission (TFR1) (week 48 - week 144): During the TFR1 period, BCR-ABL levels will be monitored until the end of the TFR1 stage (week 144) 4. Follow up: Patients who remain on half-dose nilotinib after week 48 and patients with loss of MMR at any time during the study will enter follow-up until week 144.

Patients discontinued from the treatment for any reason will be followed for survival information until week 144. All patients still on study treatment at the end of the study will be transitioned to prescription nilotinib.

The TFR2 stage will include two cohorts; an internal cohort made up of patients who participated in the TFR1 stage of this study, and an external cohort of patients who failed a first attempt at TFR with nilotinib outside of this study. The TFR2 stage is made up of 4 periods:

1. Screening for reinduction 2. Reinduction (week 0-96): Patients will be treated with asciminib 40 mg BID + nilotinib 300 mg BID for 96 weeks. Patients will proceed as follows:

* Patients with sustained DMR at the end of reinduction will enter TFR2 and asciminib + nilotinib will be discontinued. If two or more consecutive quarterly BCR-ABL RQ-PCR assessments are not performed or results are not available, the patient will not be eligible for TFR2 * Patients not eligible for TFR2 but with more than an MMR continue treatment with asciminib + nilotinib until the end of reinduction (week 96) and then continue nilotinib monotherapy at 300 mg BID until the end of the TFR2 stage (week 144). * Patients with loss of MMR at any time during reinduction or during nilotinib monotherapy will be discontinued from the study. 3. Asciminib+nilotinib treatment-free remission (TFR2) (week 96-week 144): During the TFR2 period, BCR-ABL levels will be monitored every month for one year 4. Follow up: Patients with loss of MMR during TFR2 and patients not eligible for TFR2 but with more than an MMR will be treated with nilotinib 300 mg BID and monitored until week 144. If MMR loss occurs during reinduction or during nilotinib monotherapy, patients will be discontinued from the study and treated according to clinical practice.