EPIK-B5: A Phase III, randomized, double-blind, placebo-controlled study of alpelisib (BYL719) in combination with fulvestrant for men and postmenopausal women with HR-positive, HER2-negative advanced breast cancer with a PIK3CA mutation, who progressed on or after aromatase inhibitor and a CDK4/6 inhibitor

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

EU CTIS

Registry ID

CTIS2023-509133-39-00

Acronym

CBYL719C2303

Enrollment

240

Registered

2024-07-10

Start date

2021-11-29

Completion date

Unknown

Last updated

2026-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

HER2-negative advanced breast cancer, Hormone receptor positive

Brief summary

Progression-free survival (PFS) based on BIRC assessments and using RECIST v1.1 criteria

Detailed description

Overall survival, Overall response rate (ORR) with confirmed response, clinical benefit rate (CBR) with confirmed response, duration of response (DOR) with confirmed response, and time to response (TTR) based on BIRC assessment and RECIST v1.1, PFS based on BIRC assessment and using RECIST v1.1 criteria for participants by PIK3CA mutation status assessed in ctDNA at baseline, Incidence, type and severity of adverse events per CTCAE v4.03 criteria, Time to definitive deterioration of ECOG performance status from baseline, Time to definitive (10%) deterioration in the global health status/Quality of Life (QoL) and symptom scale scores of the EORTC QLQ-C30 Change from baseline in global health status/QoL and symptom scale scores of the EORTC QLQ-C30, Time from randomization to objective tumour progression on next line treatment or death from any cause (PFS2)

Interventions

DRUGALPELISIB

DRUGPlacebo to BYL719 50 mg film-coated tablet Light pink Placebo to BYL719 200 mg film-coated tablet Light red

DRUGFULVESTRANT

Eligibility

Sex/Gender

All

Age

18 Years to No maximum

Design outcomes

Primary

Measure	Time frame
Progression-free survival (PFS) based on BIRC assessments and using RECIST v1.1 criteria	—

Secondary

Measure	Time frame
Overall survival, Overall response rate (ORR) with confirmed response, clinical benefit rate (CBR) with confirmed response, duration of response (DOR) with confirmed response, and time to response (TTR) based on BIRC assessment and RECIST v1.1, PFS based on BIRC assessment and using RECIST v1.1 criteria for participants by PIK3CA mutation status assessed in ctDNA at baseline, Incidence, type and severity of adverse events per CTCAE v4.03 criteria, Time to definitive deterioration of ECOG performance status from baseline, Time to definitive (10%) deterioration in the global health status/Quality of Life (QoL) and symptom scale scores of the EORTC QLQ-C30 Change from baseline in global health status/QoL and symptom scale scores of the EORTC QLQ-C30, Time from randomization to objective tumour progression on next line treatment or death from any cause (PFS2)	—

Measure

Time frame

—

Countries

Belgium, Bulgaria, Czechia, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Poland, Portugal, Romania, Slovakia, Spain

Outcome results

None listed

Source: EU CTIS · Data processed: Feb 4, 2026