60MO - Ovarian function in young patients (pts) treated with postneoadjuvant palbociclib (PAL) and endocrine therapy (ET) for hormone receptor (HR)-positive, HER2-negative early breast cancer (BC): explorative analysis in Penelope-B

Background

PENELOPE-B is a phase III study investigating the role of PAL + ET vs placebo + ET in HR+, HER2- early BC pts with high risk of relapse after neoadjuvant chemotherapy (NACT). Invasive disease-free survival was not improved with PAL + ET (Loibl JCO 2021). Estradiol (E2), follicle-stimulating hormone (FSH), anti-Müllerian hormone (AMH) values might be influenced by post-NACT PAL. Changes in hormones for pts treated with CDK4/6 inhibitors + ET are not well explored.

Methods

616 pts were premenopausal at baseline (BL, investigator-defined). Pts with serum samples at BL and at least before cycle (C) 7 or at end of treatment (EOT) were considered (N=576). 576 pts provided blood samples at BL, 526 before C7, 541 at EOT. Centrally assessed FSH>12.4 IU/l and E2<52.2 ng/L were defined as postmenopausal; fertile level of AMH as ≥0.22 ng/mL (central lab cut-offs). Analysed subgroups were pre- vs postmenopausal FSH/E2 at BL, age ≤40 vs >40 yrs, gonadotropin-releasing hormone analogue (GnRHa) use vs no.

Results

Median age was 43 (19-56) yrs; 46.8% pts had BMI <25, 53.2% ≥25. Hormone values are shown below. At BL, 41.6% of pts in the placebo vs 41.3% in the PAL arm had premenopausal hormone levels. Of these, 9.1 vs 13.5% (p=0.387) had postmenopausal hormone levels at C7. In pts ≤40 yrs 29.2 vs 29.5% at BL (p=1.000), 18.1 vs 23.4% at C7 (p=0.472) had postmenopausal values. More pts >40 yrs (BL 75.3%, C7 69.8%) vs ≤40 yrs (29.4, 20.7%) and without GnRHa (80.3, 72.2%) vs with (15.9, 12.1%) had postmenopausal hormone levels. Median AMH was under the detection limit at all time points. At BL 91.8 vs 93.6% had non-fertile levels of AMH (p=0.426), 94.4 vs 96.5% at C7 (p=0.298), without difference in subgroups. EOT analysis will be presented at the meeting. Table: 60MO

Detectable threshold, dt: E2=5 ng/L; P, placebo

Conclusions

PAL does not influence FSH, E2 and the ovarian reserve significantly when added to ET after NACT.

Clinical trial identification

NCT01864746.

Legal entity responsible for the study

German Breast Group.

Funding

Funding and drug were provided by Pfizer.

Disclosure

F. Marmé: Financial Interests, Personal, Other, Personal Fees: Roche, AstraZeneca, Pfizer, Tesaro, Novartis, Amgen, PharmaMar, Genomic Health, CureVac, Eisai, BMS, Clovis, Janssen-Cilag, GSK, MSD, Seagen, Myriad, Pierre Fabre; Financial Interests, Personal and Institutional, Research Grant, Grant: Gilead/immunomedics. Y. Liu: Financial Interests, Institutional, Stocks/Shares: Pfizer. M. Martin Jimenez: Financial Interests, Institutional, Research Grant, Grant: Roche; Financial Interests, Institutional, Research Grant, Grant, Consulting/Advisory Fees: Puma; Financial Interests, Institutional, Research Grant, Grant, Consulting/Advisory Fees, Speakers’ Honoraria: Novartis; Financial Interests, Institutional, Advisory Role, consulting/advisory fees, speakers’ honoraria: AstraZeneca, Amgen, Roche, Genentech, Eli Lilly, Pfizer; Financial Interests, Institutional, Advisory Role, consulting/advisory fees: Taiho Oncology, PharmaMar, Daiichi Sankyo. C. Denkert: Financial Interests, Personal, Ownership Interest, Stock and Other Ownership Interests: Sividon Diagnostics; Financial Interests, Personal, Advisory Role, Consulting or Advisory Role: MSD Oncology, Daiichi Sankyo, Molecular Health, AstraZeneca, Merck, Lilly; Financial Interests, Personal and Institutional, Advisory Role, Consulting or Advisory Role, Research Funding: Roche; Financial Interests, Institutional, Advisory Role, Research Funding: Myriad Genetics; Other, Personal, Royalties, Patents, Royalties, Other Intellectual Property: VMScope Digital Pathology Software, WO2015114146A1, WO2010076322A1, WO2020109570A1. T. Karn: Other, Personal, Other, Patent pending: EP18209672. M. van Mackelenbergh: Financial Interests, Institutional, Other, Honoraria: Amgen, AstraZeneca, Roche, Pfizer, Novartis, Lilly, Pierre Fabre, Genomic Health, Molecular Health, Gilead, Seagen, GSK. P.A. Fasching: Financial Interests, Personal, Advisory Board, Advisory Board, Invited Speaker: Novartis, Daiichi Sankyo, AstraZeneca, Eisai, Merck Sharp & Dohme, Lilly, Seagen, Roche, Gilead; Financial Interests, Institutional, Research Grant, Grant: BioNTech, Cepheid; Financial Interests, Personal and Institutional, Advisory Board, Advisory Board, Invited Speaker, Research Grant: Pfizer; Financial Interests, Personal, Advisory Board, Advisory Board: Pierre Fabre, Hexal, Agendia, Sanofi Aventis. V. Müller: Financial Interests, Personal, Invited Speaker, Speaker and Consultancy Honoraria: Amgen, Daiichi Sankyo, MSD, GSK, Gilead; Financial Interests, Personal, Invited Speaker, Speaker Honoraria: AstraZeneca, Eisai, Pfizer, Teva; Financial Interests, Personal and Institutional, Invited Speaker, Speaker and Consultancy Honoraria: Novartis, Roche; Financial Interests, Personal and Institutional, Invited Speaker, Speaker Honoraria: Seagen; Financial Interests, Personal, Advisory Role, Consultancy Honoraria: Genomic Health, Hexal, Pierre Fabre, ClinSol, Lilly; Financial Interests, Institutional, Other, Other: Genentech. E. Stickeler: Financial Interests, Personal, Other, Personal Fees: Roche, Gilead, MSD, Lilly, Pfizer, Seagen, PharmaMar. S. Loibl: Financial Interests, Institutional, Research Grant, honorarium for Ad Boards: AbbVie, Celgene; Financial Interests, Institutional, Advisory Board, honorarium for Ad Board: Amgen, Bayer, BMS, Eirgenix, GSK, Lilly, Merck; Financial Interests, Institutional, Research Grant, honorarium for Ad Boards & Lectures, Grant, Other: AstraZeneca; Non-Financial Interests, Institutional, Research Grant, honorarium for Ad Board & Lecture, Medical Writing: Daiichi Sankyo, Roche; Non-Financial Interests, Institutional, Research Grant, honorarium for Ad Board, Medical Writing: Immunomedics/Gilead; Non-Financial Interests, Institutional, Research Grant, honorarium for Ad Board, Medical Writing: Novartis, Pfizer; Financial Interests, Institutional, Invited Speaker, honorarium for Ad Board & Lecture: Pierre Fabre, prIME/Medscape; Non-Financial Interests, Institutional, Invited Speaker, honorarium for Ad Board, Medical Writing: Puma; Financial Interests, Institutional, Invited Speaker, honorarium for Lecture: Samsung; Non-Financial Interests, Institutional, Invited Speaker, honorarium for Ad Boards, Medical Writing: Seagen; Other, Institutional, Other, Patent Pending: EP14153692.0, EP21152186.9; Other, Institutional, Other, Patent Issued: EP15702464.7; Other, Institutional, Other, Patent Pending, GeparNuevo: EP19808852.8; Other, Institutional, Royalties, Patent Issued, Royalties: Digital Ki67 Evaluator. All other authors have declared no conflicts of interest.