Treatment-free Remission After Achieving Sustained MR4.5 on Nilotinib (ENESTop)

The Primary objective was to evaluate the percentage of patients in TFR within 48 weeks following nilotinib cessation.

This study originally consisted of seven phases (five treatment phases and two treatment-free phases) from which two were the focus of this primary analysis report (consolidation, TFR and treatment re-initiation) The study consisted of 2 main phases: Consolidation and TFR

Nilotinib treatment consolidation phase (NTCS): Patients who satisfied all inclusion/exclusion criteria were enrolled in the consolidation phase and continued to receive nilotinib for 52 weeks at the dose which the patient was receiving prior to study entry. If a patient maintained MR4.5 throughout the consolidation phase, he/she was eligible to enter in the TFR phase. If a patient had confirmed loss of MR4.5 during the consolidation phase, he/she was not eligible to enter in the TFR phase and continued nilotinib treatment.

Nilotinib TFR phase: Patients who were eligible to enter in the TFR phase after completing the 52 week consolidation phase stopped taking nilotinib on the first day of the TFR phase. Duration of this phase was up to 520 weeks after the last patient enters in the TFR phase.

Nilotinib treatment re-initiation phase (NTRI): If a patient had a confirmed loss of MR4 (two consecutive BCR-ABL \>0.01% IS) or loss of MMR (BCR-ABL \>0.1% IS) in the TFR phase, the patient restarted nilotinib treatment. Patients will be on nilotinib treatment for up to 520 weeks after the last patient entered the nilotinib TFR phase, or until a patient experience unacceptable toxicity, disease progression and/or treatment discontinued at the discretion of the Investigator or if the patient withdrew consent. Nilotinib cessation was not attempted for a second time in the patient who reinitiated treatment or discontinued following the TFR phase.

Nilotinib treatment continuation phase (NTCT) and Nilotinib treatment prolonged continuation phase (NTCT-P): Patients who were not eligible to enter into the TFR phase after completing the 52-week NTCS phase entered the nilotinib treatment continuation (NTCT) phase and would continue treatment with nilotinib for another 52 weeks (a total of 104 weeks of treatment). Patients who were not able to maintain MR4.5 and had a confirmed loss of MR4.5 during the NTCT phase were not eligible to enter the TFR-2 phase. These patients entered into the nilotinib prolonged treatment continuation phase (NTCT-P) and continued nilotinib treatment until 520 weeks after the last patient entered the nilotinib TFR phase, or until the patients experience unacceptable toxicity, disease progression and/or treatment would be discontinued at the discretion of the Investigator or withdrawal of consent.