BOLERO-6
After nonsteroidal aromatase-inhibitor progression in HR-positive advanced breast cancer, how does everolimus–exemestane compare with everolimus alone or capecitabine?
Trial design and population
309 postmenopausal women with HR-positive/HER2-negative advanced breast cancer progressing during or after letrozole or anastrozole.
Everolimus 10 mg daily plus exemestane 25 mg daily vs everolimus alone vs capecitabine.
309
PFS; exploratory phase II comparison
Key results
Investigator-assessed median PFS was approximately 8.4 months with everolimus–exemestane and 9.6 months with capecitabine; the phase II study was exploratory and not designed to establish definitive superiority/non-inferiority across all arms.
Source-reported outcome visualization
Median PFS (exploratory) · Investigator assessment
Source-reported endpoint and unit; median survival is not converted into an NNT.
Absolute Effect
Do not infer NNT or definitive benefit from cross-arm median differences in this exploratory phase II study.
NNT: Not quantifiable; exploratory comparison. Endpoint/time horizon are stated above; do not convert median survival differences into NNT.
NNH: Not quantifiable. Everolimus arms had stomatitis, rash, metabolic effects and pneumonitis; capecitabine had hand-foot syndrome and diarrhoea. Toxicity profiles differ.
Safety and treatment burden
Everolimus arms had stomatitis, rash, metabolic effects and pneumonitis; capecitabine had hand-foot syndrome and diarrhoea. Toxicity profiles differ.
Follow-up, maturity and limitations
Phase II comparative study.
Small exploratory design; not powered to establish equivalence. Confirm assessment method when quoting PFS estimates.
Clinical interpretation
Current-practice context · reviewed 20 October 2026
Historical evidence is separated from current sequencing. Confirm local regulatory status, current guidelines, biomarkers, prior therapies and patient-specific contraindications before applying these results. Newer treatments may have changed the preferred sequence; where NNT/NNH cannot be defensibly quantified, no surrogate calculation is made.