BELLE-2 is a Phase III, Randomized Study of
Buparlisib in Combination with Fulvestrant
1
NCT01610284/CBKM120F2302.
* PI3K pathway activation is defined as mutation in the PIK3CA gene and/or loss of PTEN expression by immunohistochemistry;
†
Dosing (28-day cycles): intramuscular injections of fulvestrant (500 mg) on Days 1 and 15 of Cycle 1, and Day 1 of all cycles
thereafter. Once-daily doses of oral buparlisib (100 mg) or placebo starting from Cycle 1, Day 15.
1. BELLE-2 Study Protocol, version no. 03; 31-July-2014.
Randomization (1:1)
Stratification based on PI3K pathway activation status* and
presence/absence of visceral disease
Run-in treatment
phase: fulvestrant
(Cycle 1, Days 1–14)
Main study cohort
n≈842
Buparlisib + fulvestrant
†
n≈421
Placebo + fulvestrant
†
n≈421
PI3K unknown cohort
n≈308
Buparlisib + fulvestrant
†
n≈154
Placebo + fulvestrant
†
n≈154
Postmenopausal patients with HR+/HER2– locally advanced
or metastatic breast cancer refractory to aromatase inhibitor
N≈1150
Molecular screening for PI3K pathway activation status*
Full population (n≈575 each arm)
