188O - EMERALD trial analysis of patient-reported outcomes (PROs) in patients with ER+/HER2_ advanced or metastatic breast cancer (mBC) comparing oral elacestrant vs standard of care (SoC) endocrine therapy

Background

The phase III EMERALD trial (NCT03778931) reported significantly prolonged progression-free survival (PFS) and a manageable safety profile with elacestrant vs SoC endocrine therapy (ET) in patients (N=478) with ER+/HER2− advanced or mBC following progression on prior CDK4/6i plus ET. PROs measuring quality of life (QoL) are reported here.

Methods

EMERALD patients (pts) completed 3 PRO tools at prespecified time points: the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30), the PRO version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE), and the EuroQoL 5 Dimension 5 Level (EQ-5D-5L).

Results

The ratio of PROs tools completed vs. PROs tools expected was 80-90% through cycle 4 and approximately 70% at cycle 6; likely due to clinical study period overlapping with COVID-19 period. Overall, the EORTC QLQ-C30 scores were similar for elacestrant and SoC, with no differences across all time points for both functional and symptom scales. However, PRO-CTCAE results showed that fewer pts who received elacestrant reported very severe nausea (4.0% vs 14.3% by cycle 6) or very severe vomiting (9.1% vs 50% by cycle 6) compared with SoC. There were no clinically meaningful differences across all time points in adverse events typically observed with pts with cancer on ET, such as fatigue, nausea, vomiting, joint and muscle pain and hot flashes. EQ-5D-5L scores were generally comparable throughout treatment for both study arms, with elacestrant showing numerically better outcomes vs SoC for mobility, self-care and usual activities. Similar trends were observed for the full intent-to-treat population and in pts with detectable estrogen receptor 1 mutations (ESR1m).

Conclusions

This analysis confirmed that QoL was maintained between treatment groups in the EMERALD trial. Together with the previously described statistically significant prolonged PFS and manageable safety profile, these PRO results provide additional evidence that oral elacestrant is clinically meaningful in this patient population with limited therapeutic options.

Clinical trial identification

NCT03778931.

Editorial acknowledgement

Jeffrey Walter, IQVIA.

Legal entity responsible for the study

Stemline Therapeutics/Menarini Group.

Funding

Stemline Therapeutics/Menarini Group.

Disclosure

J. Cortés: Financial Interests, Personal, Advisory Board: Roche, Celgene, Cellestia, AstraZeneca, Seattle Genetics, Daiichi Sankyo, Erytech, Athenex, Polyphor, Lilly, MERCK SHARP& DOHME, GSK, LEUKO, Bioasis, Clovis oncology, Boehringer Ingelheim, Ellipses, Hibercell, BioInvent, Gemoab, Gilead, Menarini, Zymeworks, Reveal Genomics; Financial Interests, Personal, Invited Speaker: Roche, Novartis, Celgene, Eisai, Pfizer, Samsung Bioepis, Lilly, MERCK SHARP& DOHME, Daiichi Sankyo; Financial Interests, Personal, Other, Consulting/advisor: Expres2ion Biotechnologies; Financial Interests, Personal, Stocks/Shares: MedSIR, Nektar Therapeutics; Financial Interests, Institutional, Research Grant: Roche, Ariad Pharmaceuticals, AstraZeneca, Baxalta GMBH/Servier Affaires, Bayer healthcare, Eisai, Guardant Health, Merck Sharp & Dohme, Pfizer, Piqur Therapeutics, Puma B, Queen Mary University of London; Other, Travel cost and expenses: Roche, Novartis, Eisai, Daiichi Sankyo, Pfizer, Gilead, AstraZeneca. F.C. Bidard: Financial Interests, Personal, Advisory Role: Pfizer, AstraZeneca, Lilly, Novartis, Radius Health, Menarini; Financial Interests, Institutional, Advisory Role: Menarini; Financial Interests, Personal, Speaker’s Bureau: Pfizer, Novartis, AstraZeneca, Roche, Lilly, Rain Therapeutics; Financial Interests, Institutional, Research Grant: Novartis, Pfizer, Menarini Silicon Biosystems, Prolynx; Financial Interests, Institutional, Other, patents: ESR1 & MSI detection techniques; Financial Interests, Personal, Other, Travel, Accommodations, Expenses: Roche, Pfizer, AstraZeneca, Novartis. A. Bardia: Financial Interests, Personal, Advisory Board: Pfizer, Novartis, Genentech, Merck, Sanofi, Eisai, Lilly, Mersana, AstraZeneca/Daiichi, Menarini, Gilead; Financial Interests, Personal, Royalties: UpToDate; Financial Interests, Institutional, Invited Speaker: Genentech, Novartis, Pfizer, Merck, Sanofi, Radius Health, Immunomedics/Gilead, Daiichi Pharma/AstraZeneca, Eli Lilly.; Non-Financial Interests, Principal Investigator: Gilead, Mersana, AstraZeneca/Daiichi, Novartis, Pfizer, Genentech, Lilly, Merck, Sanofi. V.G. Kaklamani: Financial Interests, Personal, Other, Honoraria: Genentech, Novartis, Pfizer, Genomic Health, Puma Biotechnology, AstraZeneca, Seattle Genetics, Daichi, Gilead Sciences; Financial Interests, Personal, Advisory Role: Amgen, Eisai, Puma Biotechnology, Celldex, AstraZeneca, Athenex, bioTheranostics; Financial Interests, Personal, Speaker’s Bureau: Genentech, Novartis, Genomic Health, Puma Biotechnology, Pfizer, AstraZeneca/Daiichi Sankyo; Financial Interests, Personal, Research Grant: Eisai. I. Vlachaki: Financial Interests, Personal, Full or part-time Employment: Menarini Hellas A.E. G. Tonini: Financial Interests, Personal, Full or part-time Employment: Menarini Ricerche S.p.A. N. Habboubi: Financial Interests, Personal, Full or part-time Employment: Stemline Therapeutics; Financial Interests, Personal, Leadership Role: Stemline Therapeutics. P.G. Aftimos: Financial Interests, Personal, Advisory Board: Boehringer Ingelheim, Macrogenics, Roche, Novartis, Amcure, Servier, G1 Therapeutics, Radius, Deloitte, Menarini, Gilead, Novartis, Eisai, Lilly; Financial Interests, Personal, Invited Speaker: Synthon, Amgen; Financial Interests, Institutional, Research Grant: Roche.