Estudio que evalúa la eficacia y la seguridad del tratamiento con alpelisib más fulvestrant en hombres y mujeres posmenopáusicas japoneses con cáncer de mama avanzado

Participants regardless of prior CDK4/6 inhibitor will be treated at escalating doses (200 mg, 250 mg and 300 mg, orally) of BYL719 in combination with Fulvestrant (500 mg, intramuscular).

[Part 1] Alpelisib administered at 200 mg (DL 1), 250 mg (DL 2) or 300mg (DL 3) orally once daily on a continuous dosing schedule starting on Cycle 1 Day 1 in a 28 day cycle.

If DL 1 is tolerated, the alpelisib doses of 250 mg will be investigated. If DL 2 is tolerated, the alpelisib doses of 300 mg will be investigated.

[Part 2] In the Part 2, participants will be enrolled into Cohort 2 (CDK4/6 inhibitor naive) and Cohort 3 (CDK4/6 inhibitor pre-treated) in parallel and alpelisib will be administered at the recommended dose identified in Part 1.

• BYL719

Fulvestrant is administered at a dose of 500 mg intramuscular on Cycle 1 Day 1, Day 15, and Day 1 of every cycle thereafter (where a cycle is 28 days).

• Faslodex

Participants who are CDK4/6 inhibitor naive will be treated with BYL719 at the recommended dose identified in Part 1 in combination with Fulvestrant (500 mg, intramuscular).

[Part 1] Alpelisib administered at 200 mg (DL 1), 250 mg (DL 2) or 300mg (DL 3) orally once daily on a continuous dosing schedule starting on Cycle 1 Day 1 in a 28 day cycle.

If DL 1 is tolerated, the alpelisib doses of 250 mg will be investigated. If DL 2 is tolerated, the alpelisib doses of 300 mg will be investigated.

[Part 2] In the Part 2, participants will be enrolled into Cohort 2 (CDK4/6 inhibitor naive) and Cohort 3 (CDK4/6 inhibitor pre-treated) in parallel and alpelisib will be administered at the recommended dose identified in Part 1.

• BYL719

Fulvestrant is administered at a dose of 500 mg intramuscular on Cycle 1 Day 1, Day 15, and Day 1 of every cycle thereafter (where a cycle is 28 days).

• Faslodex

Participants who are CDK4/6 inhibitor pre-treated will be treated with BYL719 at the recommended dose identified in Part 1 in combination with Fulvestrant (500 mg, intramuscular).

[Part 1] Alpelisib administered at 200 mg (DL 1), 250 mg (DL 2) or 300mg (DL 3) orally once daily on a continuous dosing schedule starting on Cycle 1 Day 1 in a 28 day cycle.

If DL 1 is tolerated, the alpelisib doses of 250 mg will be investigated. If DL 2 is tolerated, the alpelisib doses of 300 mg will be investigated.

[Part 2] In the Part 2, participants will be enrolled into Cohort 2 (CDK4/6 inhibitor naive) and Cohort 3 (CDK4/6 inhibitor pre-treated) in parallel and alpelisib will be administered at the recommended dose identified in Part 1.

• BYL719

Fulvestrant is administered at a dose of 500 mg intramuscular on Cycle 1 Day 1, Day 15, and Day 1 of every cycle thereafter (where a cycle is 28 days).

• Faslodex

A DLT is defined as an AE or abnormal laboratory value assessed as unrelated to disease, disease progression, inter-current illness, or concomitant medications that occurs within the first 2 cycles (the first 56 days) of treatment with alpelisib in combination with fulvestrant and meets any of the criteria specified in the protocol .

ORR is defined as the proportion of participants with best overall response (BOR) of confirmed complete response (CR) or confirmed partial response (PR) based on local investigator assessment per RECIST 1.1.

Safety is determined by incidence, type, and severity of adverse events per CTCAE v4.03 criteria including changes in laboratory values, vital signs, liver assessments, renal and cardiac assessments.

The number of participants with dose adjustments (reductions, interruption, or permanent discontinuation) and the reasons

The dose intensity (computed as the ratio of actual cumulative dose received and actual duration of exposure) and the relative dose intensity (computed as the ratio of dose intensity and planned dose intensity)

The duration of exposure (in months) to alpelisib and fulvestrant

Summary statistics of alpelisib plasma concentrations by time point and dose level

ORR is defined as the proportion of participants with best overall response (BOR) of confirmed complete response (CR) or confirmed partial response (PR) based on local investigator assessment per RECIST 1.1.

PFS is defined as the time from the date of first administration of study treatment until the date of the first documented progression or death due to any cause. PFS will be assessed based on local investigator assessment per RECIST 1.1.

OS is defined as the time from date of first administration of study treatment until date of death due to any cause.

CBR is defined as the proportion of participants with a best overall response of confirmed CR, or confirmed PR, or an overall response of confirmed stable disease (SD), lasting for a duration of at least 24 weeks. CR, PR, and SD are defined based on local investigator assessment per RECIST 1.1.

DOR only applies to participants whose best overall response is CR or PR based on local investigator assessment per RECIST 1.1. The start date is the date of first documented response of CR or PR (i.e. the start date of response, not the date when response was confirmed), and the end date is defined as the date of the first documented progression or death due to underlying cancer.

TTR is defined as the time from the date of first administration of study treatment until the date of the first documented response of either CR or PR, which must be subsequently confirmed (although date of initial response is used, not date of confirmation).

Time to definitive deterioration in ECOG performance status is defined as the time from the date of first administration to the date when ECOG performance status has definitively deteriorated by at least one category compared with baseline. Deterioration is considered definitive if there is no subsequent improvement in ECOG performance status back to the baseline category or above.

Incidence, type, and severity of adverse events per CTCAE v4.03 criteria including changes in laboratory values, vital signs, liver assessments, renal and cardiac assessments

The number and percentage of participants with dose interruptions and dose reductions

The dose intensity (computed as the ratio of actual cumulative dose received and actual duration of exposure) and the relative dose intensity (computed as the ratio of dose intensity and planned dose intensity)

The duration of exposure (in months) to alpelisib and fulvestrant

Summary statistics of alpelisib plasma concentrations by time point and dose level