57MO - First-line (1L) ribociclib (RIB) + endocrine therapy (ET) vs combination chemotherapy (combo CT) in HR+/HER2− advanced breast cancer (ABC): A post hoc analysis of Asian and non-Asian patients (pts) from the phase II RIGHT choice trial

Background

RIGHT Choice reported a statistically significant median progression-free survival (mPFS) benefit of ≈1 y with RIB + ET vs combo CT (24.0 vs 12.3 mo; HR, 0.54; P=.0007) in pre- or perimenopausal pts with HR+/HER2− ABC. We report outcomes in Asian and non-Asian pts from this trial.

Methods

Pre- or perimenopausal pts with HR+/HER2− ABC and no prior systemic therapy for ABC were randomized to RIB + ET or investigator’s choice of combo CT (Table). Pts had ABC for which combo CT was clinically indicated by physician’s judgment (symptomatic visceral metastases, rapid disease progression/impending visceral compromise, or markedly symptomatic non-visceral disease).

Results

Pt characteristics between arms were balanced in the Asian (n=118) and non-Asian (n=104) subgroups. Similar characteristics were seen in Asian and non-Asian pts, with some differences in BMI (median, 23.7 vs 26.3 kg/m²) as well as the proportion with symptomatic non-visceral disease (7.6% vs 21.2%) and physician-assessed visceral crisis (69.5% vs 32.7%). The PFS benefit with RIB + ET vs CT was 15.0 mo (mPFS, 25.2 vs 10.2 mo; HR, 0.43) in Asian pts and 8.3 mo (21.1 vs 12.8 mo; HR, 0.75) in non-Asian pts. In both groups, the median time to treatment (tx) failure (mTTF) was longer and the 3-mo tx failure rate (TFR) was lower with RIB + ET vs CT. In Asian pts, the overall response rate (ORR) was higher with RIB + ET than CT, with similar clinical benefit rate (CBR) and median time to response (mTTR) in both arms. In non-Asian pts, the ORR and CBR were similar in both arms, with longer mTTR for RIB + ET vs CT. The safety profile in the subgroups was consistent with that of the overall pt population.

Conclusions

This post hoc analysis confirmed a clinically meaningful PFS benefit with 1L RIB + ET vs combo CT in pre- or perimenopausal Asian and non-Asian pts with HR+/HER2− ABC. Table: 57MO

NR, not reached. ^a Unconfirmed; ^b Docetaxel + capecitabine, paclitaxel + gemcitabine, or capecitabine + vinorelbine.

Clinical trial identification

NCT03839823. Release date is September 17, 2018.

Editorial acknowledgement

Editorial assistance in the writing of the abstract was provided by Shashank Tandon, PhD of MediTech Media.

Legal entity responsible for the study

Novartis Pharmaceuticals Corporation.

Funding

Novartis Pharmaceuticals Corporation.

Disclosure

Y. Yap: Financial Interests, Personal, Other, Honoraria: Novartis, AstraZeneca, MSD, Inivata, Specialised Therapeutics, Roche, Pfizer, Lilly/DKSH, Eisai; Non-Financial Interests, Personal, Other, Travel Support: AstraZeneca, Lilly/DKSH; Financial Interests, Personal and Institutional, Research Grant: MSD. S. Im: Financial Interests, Personal, Advisory Board, no payment: AstraZeneca, Novartis, Eisai, Roche, Hanmi, Pfizer, Lilly, MSD, GSK, Daiichi Sankyo; Financial Interests, Institutional, Advisory Board: Bertis; Financial Interests, Personal, Advisory Board: Idience; Financial Interests, Institutional, Research Grant: AstraZeneca, Pfizer, Roche, Eisai, Dae Woong; Financial Interests, Institutional, Local PI, Clinical Trial Budget: AstraZeneca, Hanmi, Novartis, Roche, Pfizer, Daiichi Sankyo, MSD, Lilly; Financial Interests, Institutional, Coordinating PI, Clinical Trial Budget: Eisai; Financial Interests, Institutional, Research Grant, Clinical Trial Budget: Boryung Pharm. Y. Lu: Other, Personal and Institutional, Other, Clinical trial study fee: Novartis; Financial Interests, Institutional, Research Grant, Grant for clinical study for ESR1 mutation detected by cell free DNA: Novartis; Financial Interests, Personal, Advisory Board: Novartis, Daiichi Sankyo; Financial Interests, Personal, Speaker, Consultant, Advisor: Novartis, Pfizer, Roche, Merck Sharp & Dohme, Pfizer, Eisai, AstraZeneca, Eli Lilly, Daiichi Sankyo; Financial Interests, Personal, Other, Contracted research: Roche, Merck Sharp & Dohme, Pfizer; Financial Interests, Institutional, Research Grant: Merck Sharp & Dohme, Pfizer, AstraZeneca; Financial Interests, Personal and Institutional, Other, Clinical trial: AstraZeneca. H.A. Azim: Financial Interests, Personal, Advisory Board, honoraria for advisory boards and lecturing: Pfizer, MSD, BMS, ASZ, Lilly, Roche, Novartis; Non-Financial Interests, Personal and Institutional, Other, supporting educational activities for my academic institution: Novartis, Pfizer, MSD, BMS, ASZ; Financial Interests, Personal and Institutional, Other, supporting educational activities for my academic institution: Lilly. Y. Eralp: Financial Interests, Personal, Advisory Board: Novartis, Merck, Sharp and Dohme, AstraZeneca; Financial Interests, Personal, Other, Educational fee: Gilead, GSK; Financial Interests, Institutional, Research Funding, Research support: Roche; Non-Financial Interests, Personal, Other, Non-compansated educational program: Roche, Novartis; Financial Interests, Personal, Advisory Board, Non-compansated mentorship program: Boston Scientific; Financial Interests, Personal, Other, Satellite meeting fee: Roche. A. Thuerigen: Financial Interests, Personal and Institutional, Full or part-time Employment: Novartis; Financial Interests, Personal and Institutional, Stocks/Shares: Novartis. T. Delgar Alfaro: Financial Interests, Personal and Institutional, Full or part-time Employment: Novartis; Financial Interests, Personal and Institutional, Stocks/Shares: Novartis. J. Wu: Financial Interests, Personal and Institutional, Full or part-time Employment: Novartis; Financial Interests, Personal and Institutional, Stocks/Shares: Novartis. M. Gao: Financial Interests, Personal and Institutional, Full or part-time Employment: Novartis; Financial Interests, Personal and Institutional, Stocks/Shares: Novartis. N.S. El Saghir: Financial Interests, Personal, Invited Speaker, Speaker conference: AstraZeneca, Roche; Financial Interests, Personal, Invited Speaker, Conference: Lilly, Pfizer; Financial Interests, Personal, Invited Speaker, Speaker and/or adboard: MSD; Financial Interests, Personal, Invited Speaker, Speaker meeting: Pierre Fabre; Financial Interests, Institutional, Coordinating PI, Clinical Trial co-PI: Novartis. All other authors have declared no conflicts of interest.