Study to Determine the Efficacy and Safety of Asciminib in Pediatric Patients With Ph+ CML-CP

MMR is defined as BCR::ABL1 IS ≤0.1%. MMR is defined as a ≥ 3.0 log reduction in BCR::ABL1 transcripts compared to the standardized baseline equivalent to ≤ 0.1 % BCR::ABL1/ABL % by international scale as measured by RQ-PCR.

MMR is defined as BCR::ABL1 IS ≤0.1%. MMR is defined as a ≥ 3.0 log reduction in BCR::ABL1 transcripts compared to the standardized baseline equivalent to ≤ 0.1 % BCR::ABL1/ABL % by international scale as measured by RQ-PCR.

MMR is defined as BCR::ABL1 IS ≤0.1%. MMR is defined as a ≥ 3.0 log reduction in BCR::ABL1 transcripts compared to the standardized baseline equivalent to ≤ 0.1 % BCR::ABL1/ABL % by international scale as measured by RQ-PCR.

Complete hematologic response (CHR) is defined as all of the following present for ≥ 4 weeks (which means present at least at 2 visits 4-week apart, with no intermediate visit showing no CHR):

• White blood cell(s) (WBC) count < 10 x 10^9/L
• Platelet count < 450 x 10^9/L
• Basophils < 5%
• No blasts and promyelocytes in peripheral blood
• Myelocytes + metamyelocytes < 5% in peripheral blood
• No evidence of extramedullary disease, including spleen and liver

Cytogenetic response is defined as follows:

• Complete (CCyR) - 0% Ph+ metaphases
• Partial (PCyR) - >0 to 35% Ph+ metaphases
• Major* (MCyR) - 0 to 35% Ph+ metaphases
• Minor (mCyR) - >35 to 65% Ph+ metaphases
• Minimal - >65 to 95% Ph+ metaphases
• None - >95 to 100% Ph+ metaphases Bone marrow aspirate for cytogenetic analyses will be performed at screening, and upon unfavorable response to treatment at the physician's discretion.

Time to the first response is defined as: date of the first documented occurrence of the response or time from first study drug intake to first response - date of the first study treatment intake + 1.

Duration of response is defined as the time between the date of the first documented occurrence of the response and the earliest date of confirmed loss of the response, progression to accelerated phase/blast crisis (AP/BC) or CML-related death for participants in the respective Responder Set.

TTF is defined as the time from the first study drug intake to the first/earliest documented date of any of the following events: unfavorable response to treatment, confirmed loss of MMR at any time while on study treatment and discontinuation from study treatment due to any reason.

EFS is defined as the time from the first study drug intake to the earliest occurrence of the following events: unfavorable response to treatment, confirmed loss of MMR at any time while on study treatment, discontinuation from the study treatment due to an adverse event (AE) and death due to any cause.

OS is defined as the time from the first study drug intake to the date of death from any cause during the study (including death observed during the survival follow-up period after discontinuation of study treatment).

To assess growth and sexual maturation. An X-ray of the left hand and wrist to assess bone age will be performed at screening and every 48 weeks until end of treatment (EOT). This assessment will no longer be required for participants once bone maturity in post-puberty stage is confirmed by the last X-ray.

To assess growth and sexual maturation. Tanner staging will be based on external genitalia, breast and pubic hair examination. Tanner staging will be assessed for all study participants at screening. Participants who do not have a baseline Tanner Stage of 5 will continue to be assessed every 24 weeks until achievement of Tanner Stage 5 on both secondary sexual characteristics or EOT, whichever comes first. Once a participant reaches stage 5, examinations do not need to be conducted anymore. For all male participants, Tanner Stage 5 will be achieved once the participant has demonstrated both stage 5 genitalia development and stage 5 pubic hair development. For all female participants, Tanner Stage 5 will be achieved once the participant has demonstrated both stage 5 breast development and stage 5 pubic hair development.

AUClast: The AUC from time zero to the last measurable concentration sampling time.

AUCtau: The AUC calculated to the end of a dosing interval (tau) at steady-state.

Cmax is the maximum (peak) observed plasma drug concentration after single dose administration.

Tmax is the time to reach maximum (peak) plasma drug concentration (h) after administration.

Ctrough refers to the lowest concentration a drug reaches in the bloodstream immediately before the next dose is administered.