Real-World Outcomes of Ribociclib and Aromatase Inhibitor Use in First Line Hormone Receptor Positive, HER2-Negative Metastatic Breast Cancer

Vanessa Wong; Richard de Boer; Sally Baron-Hay; Robert Blum; Frances Boyle; Susan Chua; Kerrie Clarke; Katharine Cuff; Michael Green; Elgene Lim; Kelly Mok; Louise Nott; Michelle Nottage; Ali Tafreshi; Daphne Tsoi; Anthony Uccellini; Wei Hong; Peter Gibbs; Sheau Wen Lok

doi:10.1016/j.clbc.2022.08.011

Real-World Outcomes of Ribociclib and Aromatase Inhibitor Use in First Line Hormone Receptor Positive, HER2-Negative Metastatic Breast Cancer

Clin Breast Cancer. 2022 Dec;22(8):792-800. doi: 10.1016/j.clbc.2022.08.011. Epub 2022 Aug 30.

Authors

Vanessa Wong¹, Richard de Boer², Sally Baron-Hay³, Robert Blum⁴, Frances Boyle⁵, Susan Chua⁶, Kerrie Clarke⁷, Katharine Cuff⁸, Michael Green⁹, Elgene Lim¹⁰, Kelly Mok¹¹, Louise Nott¹², Michelle Nottage¹³, Ali Tafreshi¹⁴, Daphne Tsoi¹⁵, Anthony Uccellini¹⁶, Wei Hong¹⁷, Peter Gibbs¹⁸, Sheau Wen Lok¹⁹

Affiliations

¹ Personalised Oncology Division, Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia. Electronic address: wong.v@wehi.edu.au.
² Department of Medical Oncology, Peter MacCallum Cancer Centre, Parkville, VIC, Australia; St Vincent's Private Hospital, Fitzroy, VIC, Australia.
³ Northern Cancer Institute, St Leonards, NSW, Australia.
⁴ Department of Medical Oncology, Bendigo Health, Bendigo, VIC, Australia.
⁵ The Mater Hospital, North Sydney, NSW, Australia.
⁶ Department of Medical Oncology, Eastern Health, Box Hill, VIC, Australia.
⁷ Albury Wodonga Regional Cancer Centre, Albury Wodonga Health, East Albury, NSW, Australia.
⁸ Department of Medical Oncology, Princess Alexandra Hospital, Woolloongabba, QLD, Australia.
⁹ Epworth Freemasons, East Melbourne, VIC, Australia.
¹⁰ St Vincent's Clinical School, University of New South Wales, NSW, Australia.
¹¹ Department of Medical Oncology, Liverpool Hospital, Liverpool, NSW, Australia.
¹² Department of Medical Oncology, Royal Hobart Hospital, Hobart, TAS, Australia.
¹³ Department of Medical Oncology, Royal Brisbane and Women's Hospital, Herston, QLD, Australia.
¹⁴ Wollongong Private Hospital, Wollongong, NSW, Australia.
¹⁵ St John of God Subiaco Hospital, Subiaco, WA, Australia.
¹⁶ Department of Medical Oncology, Olivia Newton-John Cancer and Wellness Centre, Austin Health, Heidelberg, VIC, Australia.
¹⁷ Personalised Oncology Division, Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.
¹⁸ Personalised Oncology Division, Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Medical Oncology, Western Health, Footscray, VIC, Australia.
¹⁹ Personalised Oncology Division, Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Medical Oncology, Peter MacCallum Cancer Centre, Parkville, VIC, Australia.

PMID: 36151018
DOI: 10.1016/j.clbc.2022.08.011

Abstract

Background: International guidelines recommend combining a CDK4/6 inhibitor and endocrine therapy (ET) as first line treatment for hormone receptor (HR) positive, HER2 negative metastatic breast cancer (MBC). Results from MONALEESA-2 demonstrate superior progression free survival (PFS) and overall survival (OS) with ribociclib (CDK4/6 inhibitor) and ET compared to ET alone. Real world outcomes have yet to be reported.

Materials and methods: KARMA is a non-interventional registry of Australian patients receiving first-line treatment with ribociclib and aromatase inhibitor (AI), obtained via a Medicine Access Program (MAP) for HR+, HER2- MBC. Outcomes were compared with the ribociclib/letrozole cohort in MONALEESA-2.

Results: Data from 160 patients at 17 sites was analysed. Median follow-up is 36.5 months. Compared to MONALEESA-2, patients were numerically younger (54.3 vs. 62 years), with higher rates of bone-only metastases (31% vs. 21%). A total of 63 of 160 (39%) patients remain on treatment. A total of 56% of patients had at least 1 dose reduction, with neutropenia (68%) and abnormal liver enzymes (17%) the most common reasons. A total of 17 of 160 (11%) discontinued treatment due to toxicity, with no treatment related deaths. Median PFS was not reached (95% CI 29.9- NR), with PFS at 12 months and 18 months being 76% and 67% respectively versus 25.3 months, 73% and 63% in MONALEESA-2.

Conclusion: The ribociclib and AI combination was well tolerated in this real-world setting. The KARMA registry cohort achieved a superior PFS (>36.5 months) to MONALEESA-2, potentially due to more favourable baseline disease characteristics. Less frequent assessment scheduling in this non trial setting may also contribute.

Keywords: Breast cancer; Medicine access programs; Registries.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Antineoplastic Combined Chemotherapy Protocols / adverse effects
Aromatase Inhibitors* / therapeutic use
Australia
Breast Neoplasms* / pathology
Female
Humans
Letrozole
Receptor, ErbB-2
Receptors, Estrogen

Substances

Aromatase Inhibitors
ribociclib
Letrozole
Receptors, Estrogen
Receptor, ErbB-2