Background

Abemaciclib demonstrated a sustained benefit in invasive disease-free survival and a tolerable safety profile in monarchE at 42 months (mo) median follow-up (mFU). At 19 mo mFU, initial patient (pt)-reported outcome (PRO) findings supported a tolerable profile with most pts remaining on treatment (tx). With all pts now off abemaciclib, we report data including the full 2-year tx period and follow-up to evaluate long-term impact on PROs.

Methods

Pts completed PROs including FACT-B, FACT-ES, and FACIT-Fatigue at baseline, 3, 6, 12, 18, 24 mo, and 1, 6, 12 mo after tx discontinuation (dc). Mixed effects repeated measures model estimated changes from baseline within and between arms for summary scores and individual items. Meaningful change was defined as 0.5 standard deviation of baseline summary scores and 1 point for individual items. Additional analyses included frequencies of responses to items associated with adverse events (AEs; e.g., diarrhea, fatigue) and tx bother.

Results

For the 5591 treated pts, PRO completion rates were >90% on tx and ∼80% during follow-up. Within- and between-arms, differences in mean changes from baseline for all PROs were less than prespecified thresholds for meaningful difference, except for diarrhea, with worse scores in abemaciclib plus ET at 3 and 6 mo. During tx, most pts reported being bothered “a little bit” or “not at all” by side effects in both arms and most pts (79-85%) on abemaciclib reported “not at all” to “somewhat” for diarrhea (Table). During post-tx follow-up, PROs in both arms were similar to baseline, with ≥80% of pts on abemaciclib arm reporting “not at all” for diarrhea.Table: 93MO

Distribution of responses to key PRO items at selected assessments**

Conclusions

Adjuvant abemaciclib added to ET did not result in meaningful differences in PROs, except for diarrhea,which is considered clinically manageable. Long-term findings suggest reversibility of these effects after tx dc and can help inform pt risk/benefit assessment.

Clinical trial identification

NCT0315599.

Editorial acknowledgement

Medical writing support was provided by Trish Huynh (Eli Lilly and Company, IN, USA).

Legal entity responsible for the study

Eli Lilly and Company.

Funding

Eli Lilly and Company.

Disclosure

N. Harbeck: Financial Interests, Personal, Invited Speaker: AstraZeneca, Daiichi Sankyo, Lilly, MSD, Novartis, Pierre Fabre, Roche, Seagen, Medscape, Art Tempi, Onkowissen, Gilead, Sanofi, Exact Sciences; Financial Interests, Personal, Advisory Board: AstraZeneca, Daiichi Sankyo, Novartis, Pfizer, Roche, Sandoz-Hexal, Seagen, Aptitude Health, Gilead, Sanofi; Financial Interests, Personal, Other, Husband: WSG (Husband); Financial Interests, Personal, Ownership Interest: West German Study Group; Financial Interests, Institutional, Funding: AstraZeneca, BMS, Daiichi Sankyo, Lilly, MSD, Novartis, Pierre Fabre, Roche, Palleos, Seagen, TRIO, WSG; Non-Financial Interests, Member, Member German AGO Breast Guideline Committee: AGO Breast Committee; Non-Financial Interests, Member, Breast Cancer Educational Programs: ESO/ESCO; Other, Founding Editor: BreastCare Journal. V. Guarneri: Financial Interests, Personal, Invited Speaker: Eli Lilly, Novartis, Amgen, GSK; Financial Interests, Personal, Advisory Board: Eli Lilly, Novartis, MSD, Gilead, Sanofi, Merck Serono, Exact Sciences, Eisai, Olema Oncology; Financial Interests, Personal, Expert Testimony: Eli Lilly; Financial Interests, Institutional, Invited Speaker: Eli Lilly, Roche, BMS, Novartis, AstraZeneca, MSD, Synton Biopharmaceuticals, Merck, GlaxoSmithKline, Daiichi Sankyo, Nerviano; Non-Financial Interests, Member: ASCO. J. Cruz Jurado: Financial Interests, Personal, Advisory Board: PharmaMar, Roche, Lilly, Pfizer, Novartis, Gilead, AstraZeneca, Daiichi, Seagen, GSK, Bayer; Financial Interests, Personal, Invited Speaker: PharmaMar, Roche, Lilly, Pfizer, Novartis, Eisai, Gilead, AstraZeneca, Daiichi, Seagen, Esteve, Roche. M. Takahashi: Financial Interests, Personal, Other: AstraZeneca, Eli Lilly and Company, Eisai, MSD, Daiichi Sankyo, Pfizer. C.H. Barrios: Financial Interests, Personal, Advisory Board, Consulting Scientific Presentations: GSK, Novartis, Pfizer, Roche, Eisai, Bayer, MSD, AstraZeneca, Zodiac, Lilly, Sanofi; Financial Interests, Personal, Advisory Board, Consultation: Boehringer; Financial Interests, Personal, Advisory Board, Scientific Presentations Consulting AD Board: Daiichi Sankyio; Financial Interests, Personal, Ownership Interest, Virtual APP: THUMMI; Financial Interests, Personal, Stocks/Shares, Clinical Research Company: Medsir; Financial Interests, Institutional, Research Grant, Research Funding To The Institution: Pfizer, Amgen, GSK, Lilly, Sanofi, Merk, Biomarin, BMS, Medivation, Exelixis, Merck KGAA, Shangai Henlius Biothech, Polyphor, PharmaMar; Financial Interests, Institutional, Research Grant, Research Funding to the institution steering Committee: Novartis, AstraZeneca, Daiichi; Financial Interests, Institutional, Research Grant, Research Funding to the institution steering committee: ROCHE; Financial Interests, Institutional, Invited Speaker, Research funding to the institution: Nektar, Regeneron, Janssen, OBI Pharma, Seagen, Checkpoint Therapeutics, Novocure, Aveo Oncology, Takeda, Celgene, TRIO, PPD, Syneos health, DOCS, Labcorp, IQIVIA, Parexel, Nuvisan, PSI, Medplace; Financial Interests, Institutional, Invited Speaker, Research funding to the institution Steering committee: Myovant; Non-Financial Interests, Invited Speaker, Member of Executive Board: BIG International Group; Non-Financial Interests, Leadership Role, Latin American Cooperative Oncology Group: LACOG; Non-Financial Interests, Other, Chair, International Educational Steering Group: ASCO; Non-Financial Interests, Advisory Role, Member Compliance Committee: ESMO. R.J. Wei: Financial Interests, Personal, Full or part-time Employment: Eli Lilly and Company; Financial Interests, Personal, Stocks/Shares: Eli Lilly and Company. B. San Antonio: Financial Interests, Personal, Stocks/Shares: Eli Lilly and Company; Financial Interests, Personal, Full or part-time Employment: Eli Lilly and Company. A.M. Liepa: Financial Interests, Personal, Full or part-time Employment: Eli Lilly and Company; Financial Interests, Personal, Stocks/Shares: Eli Lilly and Company. M. Martin Jimenez: Financial Interests, Personal, Advisory Board: AstraZeneca, Lilly, Roche/Genentech, Daiichi Sankyo; Financial Interests, Personal, Invited Speaker: Pfizer, AstraZeneca, Lilly, Novartis, Roche/Genentech; Financial Interests, Institutional, Research Grant: Novartis, Roche, Puma; Non-Financial Interests, Invited Speaker: TRIO; Non-Financial Interests, Leadership Role: GEICAM. S.R.D. Johnston: Financial Interests, Institutional, Research Grant, Research funding to institute for laboratory studies and clinical trials: Pfizer, Puma Biotechnology, Eli Lilly and Company, AstraZeneca, Novartis, Roche/Genentech; Financial Interests, Other, Consulting or advisory role: Eli Lilly and Company, AstraZeneca, Puma Biotechnology, Pfizer, Novartis, Sanofi Genzyme; Other, Speaker’s Bureau, Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events: Pfizer, Eisai, AstraZeneca, Roche/Genentech. S.M. Tolaney: Other, Institutional, Other, Funding for study: Eli Lilly and Company; Other, Personal, Other, Honorariums: Eli Lilly and Company; Financial Interests, Institutional, Research Grant: AstraZeneca, Merck , Nektar, Novartis, Pfizer, Genentech/Roche, Gilead, Exelixis, BMS, Eisai, Nanostring, Cyclacel, Sanofi, Seagen; Other, Personal, Advisory Board, Honorarium: AstraZeneca, Eli Lilly and Company, Merck, Novartis, Pfizer, Genentech/Roche, Gilead, BMS; Other, Personal, Advisory Board: Eisai, Sanofi, Seagen, Daiichi Sankyo, Athenex, OncoPep, Kyowa Kirin Pharma, Cytomx, Certara, Mersana Therapeutics, Ellipses Pharma, 4D Pharma, OncoSec, Infinity Therapeutics, BeyondSpring Pharma, OncXerna, Zymeworks, Zentalis, ARC Therapeutics, Reveal Genomics, Blueprint Medicines, Myovant, Umoja Biopharma, Menarini/Stemline. All other authors have declared no conflicts of interest.