Conexiant’s news site is now MDSpire News. Learn more
Advertisement
Novel Treatment Combination Improves Progression-Free Survival in Most Common Form of Metastatic Breast Cancer
Patients with estrogen-receptor-positive (ER+) HER-2-negative advanced breast cancer experienced significantly improved progression-free survival (PFS) when treated with an oral combination regimen that included giredestrant, a novel, next-generation selective ER degrader and full antagonist (SERD), compared to a standard combination approach.
Clinical Report: Giredestrant Combination Improves PFS in Metastatic Breast Cancer
Overview
In the phase 3 evERA Breast Cancer study, giredestrant plus everolimus significantly improved progression-free survival (PFS) compared with endocrine therapy plus everolimus in patients with ER-positive, HER2-negative advanced breast cancer. Median PFS was 10.0 versus 5.5 months in the ESR1-mutated subgroup and 8.8 versus 5.5 months in the intention-to-treat population; overall survival data remain immature.
Background
Estrogen-receptor-positive tumors account for approximately 70% of breast cancers, and metastatic disease can be difficult to treat. CDK4/6 inhibitors have improved outcomes, but treatment options may be limited after disease progresses on these agents. The evERA study evaluated giredestrant, an oral selective estrogen receptor degrader and full antagonist, with everolimus against endocrine therapy plus everolimus. The study focused on PFS in the overall population and in patients with ESR1 mutations.
Data Highlights
Population
Giredestrant plus everolimus
Standard endocrine therapy plus everolimus
Reported effect
ESR1-mutated subgroup
Median PFS: 10.0 months
Median PFS: 5.5 months
63% reduction in risk of progression or death
Intention-to-treat population
Median PFS: 8.8 months
Median PFS: 5.5 months
44% reduction in risk of progression or death
Study population and follow-up
373 patients randomized; approximately 55% had ESR1 mutations; median follow-up was 18.6 months
Key Findings
evERA was a global, randomized, open-label phase 3 study of oral giredestrant plus everolimus versus endocrine therapy plus everolimus in ER-positive, HER2-negative advanced breast cancer.
The trial enrolled 373 patients, and approximately 55% had ESR1 mutations.
In the ESR1-mutated subgroup, median PFS was 10.0 months with giredestrant plus everolimus and 5.5 months with the comparator regimen, corresponding to a reported 63% reduction in risk of progression or death.
In the intention-to-treat population, median PFS was 8.8 months with giredestrant plus everolimus and 5.5 months with the comparator, corresponding to a reported 44% reduction in risk of progression or death.
Overall survival data were immature at the reported analysis; the source states that they were trending favorably.
The giredestrant regimen's safety profile was described as manageable and consistent with the known safety profiles of the individual study treatments.
Clinical Implications
The study authors describe giredestrant plus everolimus as a potential treatment option for patients with metastatic ER-positive breast cancer, including those with ESR1-mutated tumors, after progression on CDK4/6 inhibitor-based treatment. The reported PFS findings do not yet establish an overall-survival benefit, for which the data remain immature.
Conclusion
In evERA, giredestrant plus everolimus improved median PFS over endocrine therapy plus everolimus in both the ESR1-mutated and intention-to-treat populations. Further overall-survival follow-up remains pending.
