Nilotinib Treatment-free Remission Study in CML (Chronic Myeloid Leukemia) Patients

The outcome measure was the percentage of participants in molecular response 4.5 (MR4.5) at 48 weeks after initiation of the treatment-free remission (TFR) phase. Participants who required reinitiation of treatment were considered non-responders. MR4.5 corresponds to a BCR-ABL transcript level ≤0.0032% on the International Scale (IS), representing a deep molecular response.

This outcome measure was the percentage of participants in major molecular response (MMR) assessed at multiple timepoints after initiation of the treatment-free remission (TFR) phase. Participants who required re-initiation of treatment at any time prior to the respective assessment were considered non-responders.

This secondary outcome measure was the percentage of participants in molecular response 4.5 (MR4.5) assessed at multiple timepoints after initiation of the treatment-free remission (TFR) phase. Participants who required reinitiation of treatment at any time prior to the respective assessment were considered non-responders. MR4.5 corresponds to a BCR-ABL transcript level ≤0.0032% on the International Scale (IS).

This outcome measure was the number of participants in major molecular response (MMR) assessed at multiple timepoints after initiation of the treatment-free remission (TFR) phase of nilotinib. At each assessment time point, participants with available MMR data were counted. Participants who reinitiated nilotinib treatment for less than 12 weeks prior to the respective assessment time point were excluded from the analysis at that time point.

This outcome measure was the number of participants in molecular response 4.5 (MR4.5) assessed at multiple timepoints after initiation of the treatment-free remission (TFR) phase of nilotinib. At each assessment time point, participants with available MR4.5 data were counted. Participants who reinitiated nilotinib treatment for less than 12 weeks prior to the respective assessment time point were excluded from the analysis at that time point. MR4.5 corresponds to a BCR-ABL transcript level ≤0.0032% on the International Scale (IS).

Percentage of patients who achieved MMR within 12 weeks of re-initiation of treatment with nilotinib defined as the number of patients who were in MMR at least at 1 assessment within 12 weeks after re-start of nilotinib treatment divided by the number of patients who were re-initiated for at least 12 weeks.

The percentage of patients who were in stable MMR after achieving a response in the NTRI phase at multiple timepoints was calculated by dividing the number of participants achieving MMR any time during the NTRI phase and having the same response at those timepoints after the first achievement of MMR, irrespective of whether there was loss of MMR in between, by the number of patients who achieved MMR at any time during the NTRI phase.

The proportion of patients who were in stable MR4.5 after achieving a response in the NTRI phase at multiple timepoints was calculated by dividing the number of participants achieving MR4.5 any time during the NTRI phase and having the same response at those timepoints after the first achievement of MR4.5, irrespective of whether there was loss of MR4.5 in between, by the number of patients who achieved MR4.5 at any time during the NTRI phase.

The BCR-ABL ratio (%) represents the level of BCR-ABL fusion gene transcripts relative to a control gene (ABL) measured in peripheral blood samples using quantitative reverse transcription polymerase chain reaction (RT-PCR). Results are expressed as a percentage on the International Scale (IS), a standardized reporting method that allows comparison across laboratories. The BCR-ABL ratio is used to assess the molecular response to treatment, with lower values indicating a reduced disease burden.

This outcome measure was defined as the time from the date of reinitiation of nilotinib treatment following loss of major molecular response (MMR) to the date of first documented achievement of MMR. Participants who did not regain MMR after reinitiation of treatment on or before the data cut-off date were censored at the date of their last available BCR-ABN PCR assessment.

This outcome measure was defined as the time from the date of reinitiation of nilotinib treatment following loss of major molecular response (MMR) to the date of first documented achievement of molecular response 4.5 (MR4.5). Participants who did not regain MR4.5 after reinitiation of treatment on or before the data cut-off date were censored at the date of their last available BCR-ABN PCR assessment. MR4.5 corresponds to a BCR-ABN transcript level ≤0.0032% on the International Scale (IS).

Treatment-free survival (TFS) was defined as the time from the start of the treatment-free remission (TFR) phase to the earliest occurrence of loss of major molecular response (MMR), reinitiation of treatment for any reason, progression to accelerated phase (AP) or blast crisis (BC), or death due to any cause. Participants without an event on or before the data cut-off date were censored at the date of their last available disease assessment (polymerase chain reaction, cytogenetic, hematologic, or extramedullary assessment).

Progression-free survival (PFS) was defined as the time from the start of the treatment-free remission (TFR) phase to the earliest occurrence of disease progression to accelerated phase (AP) or blast crisis (BC), or death due to any cause. Participants without an event on or before the data cut-off date were censored at the date of their last available disease assessment (cytogenetic, hematologic, or extramedullary assessment) or last contact for participants in follow-up.

Overall survival (OS) was defined as the time from the start of the treatment-free remission (TFR) phase to death due to any cause. Participants who were alive on or before the data cut-off date were censored at the date of their last assessment or last known alive date for participants in follow-up.

This outcome measure summarized the overall occurrence of adverse events related to nilotinib during the study. A study drug-related adverse event was defined as any adverse event assessed by the investigator as related to nilotinib and reported during the nilotinib treatment consolidation (NTCS) phase, the treatment-free remission (TFR) phase, or the nilotinib treatment re-initiation (NTRI) phase.

This outcome measure was the number of participants who developed BCR-ABL1 mutations associated with resistance to nilotinib following loss of major molecular response (MMR) after suspension of nilotinib treatment. Mutations assessed included, but were not limited to, T315I, E255K, Y253H, F359V, F359C, and F359I. The endpoint was calculated as the number of participants with at least one detected BCR-ABL1 mutation divided by the number of participants who experienced loss of MMR after nilotinib suspension.