Venous thromboembolic events (VTE), elevated aminotransferases (EAT) and interstitial lung disease (ILD) are adverse events (AEs) for abemaciclib (oral CDK4 & 6 inhibitor). In monarchE, patients (pts) receiving abemaciclib+endocrine therapy (ET) as adjuvant treatment (txt) of HR+, HER2- high-risk early breast cancer (EBC) reported these AEs more frequently vs ET alone pts.
The safety population (pop) comprised 5591 treated (tx) pts (median duration of abemaciclib: 17 months). The protocol included management guidance for AEs. Pts with history of VTE were not eligible. Risk factors for VTE (Khorana risk score) and adjuvant radiotherapy (95.4% pts) were well balanced across arms.
In abemaciclib tx pts: Most VTEs were G≥3 (1.3%), primarily pulmonary embolism (0.9%) (Table). Of pts experiencing VTE, 94% received anti-coagulants and 19.4% discontinued abemaciclib or all txt due to VTE. VTEs were increased with tamoxifen txt; G≥3 VTEs were higher in pts with body mass index (BMI)> 25 (1.8%) vs BMI<25 (0.6%). 85% of G≥3 EAT were single occurrences; incidence was highest early on txt (∼3 months). Of pts experiencing G≥3 EAT, 71% had dose hold/reduction and 16% discontinued due to EAT. All G≥3 alanine aminotransferase (ALT) increases, per central lab, were reversible with dose modification or discontinuation. No pts had drug-induced liver injury (no Hy’s law cases). Most ILD events were G1 (1.4%). Of pts experiencing ILD, 52% were tx with steroids/antibiotics and 23% discontinued abemaciclib or all txt due to ILD. ILD was higher in Asians (6.6%; G1: 4.9%; G≥3: 0.3%; 13% of Asian pts with ILD discontinued (0.9% of pop)). Characteristics of VTEs, EAT and ILD a1st ET tamoxifen 4.1%; AIs 1.7%. b9 preferred terms, incl ALT and aspartate aminotransferases (AST). csafety pop v Asians: ALT: 2.4% v 4.2%; AST: 1.8% v 3.1%. dILD incl pneumonitis, radiation pneumonitis. epossibly related to txt 454.
Abemaciclib+ET ET N=2791 N=2800 VTE EATb ILDd VTE EATb ILDd Pts with ≥1 TEAE; n (%) Any grade 67 (2.4)a 356 (12.8) 82 (2.9) 16 (0.5) 181 (6.5) 34 (1.2) G≥3 37 (1.3) 87 (3.1)c 11 (0.4) 7 (0.3) 24 (0.9) 1 (0.1) Serious AEs 33 (1.2) 11 (0.4) 14 (0.5) 8 (0.3) 2 (0.1) 1 (0.0) Deaths 0 (0.0) 0 (0.0) 1 (0.0)e 1 (0.0) 0 (0.0) 0 (0.0) Discontinuations 13 (0.5) 22 (0.8) 19 (0.7) 2 (0.1) 0 (0.0) 0 (0.0) Time to onset of first AE; median, days 182 113 190 188 140 158
VTE, EAT and ILD were manageable with dose adjustments and comedications in pts with EBC; results were consistent with the known safety profile of abemaciclib. Although ILD was higher in Asian pop, G≥3 AEs and discontinuations were similar. Most pts experiencing these AEs could continue abemaciclib.
NCT03155997.
Eglantine Julle-Daniere.
Eli Lilly.
Eli Lilly.
M. Toi: Honoraria (self), Research grant/Funding (self), Research grant, Lecture honoraria: Chugai, Takeda, Pfizer, Taiho, Eisai, AstraZeneca, Shimadzu, Yakult; Honoraria (self), Advisory/Consultancy, Research grant/Funding (self), Research grant, Lecture honoraria, Advisory role for a drug development: Kyowa-Kirin, Daiichi Sankyo; Research grant/Funding (self): JBCRG association, Astellas; Advisory/Consultancy, Research grant/Funding (self): Eli Lilly; Honoraria (self), Lecture Honoraria: MSD, Exact Science, Novartis; Honoraria (self), Advisory/Consultancy, Honoraria for an advisory meeting: Konica Minolta, BMS; Honoraria (self), Research grant/Funding (self), Research Fund and Honoraria for lecture: Nippon Kayaku; Research grant/Funding (self): AFI Technologies; Advisory/Consultancy: Athenex Oncology, Bertis, Terumo, Kansai Medical Net; Advisory/Consultancy, Research grant/Funding (self): Luxonus; Research grant/Funding (self): Shionogi, GL Science; Officer/Board of Directors: JBCRG association, Organisation for Oncology and Translational Research, Kyoto Breast Cancer Research Network. N. Harbeck: Shareholder/Stockholder/Stock options: West German Study Group; Honoraria (self): Roche, Novartis, Amgen, Pfizer, Genomic Health, AstraZeneca, Zodiac Pharma, Pierre Fabre; Advisory/Consultancy: Roche/Genentech, Novartis, Celgene, Pfizer, Eli Lilly, Sandoz, Daiichi Sankyo, Agendia, AstraZeneca, Merck Sharp & Dohme, Odonate Therapeutics, Seattle Genetics, West German Study Group, Pierre Fabre; Research grant/Funding (institution): Roche/Genentech (Inst), Novartis (Inst), Pfizer (Inst), Lilly (Inst), Merck Sharp & Dohme (Inst). J.M. Puig: Honoraria (self), Personal fees: Protocol JPCF. J. Cruz: Honoraria (self), Advisory/Consultancy, Lectures, Travel, Advisory: PharmaMar, Roche, Novartis, Pfizer; Honoraria (self), Advisory/Consultancy, Lectures, Advisory: Eli Lilly, AstraZeneca; Advisory/Consultancy: Daiichi, Seagen, Glaxo; Honoraria (self), Advisory/Consultancy: Eisai; Honoraria (self), Lectures: Bayer. M. Takahashi: Honoraria (self): Eli Lilly; Honoraria (self): AstraZeneca; Honoraria (self): Pfizer; Honoraria (self), Research grant/Funding (self): Eisai; Research grant/Funding (self): Kyowa Kirin; Research grant/Funding (self): Taiho. M. Hulstijn, E.A. Twum, A. Regev, B. San Antonio: Full/Part-time employment: Eli Lilly. D.M. Median: Honoraria (self), Advisory/Consultancy, Research grant/Funding (institution), Institutional research funding, Honoraria, Lecture fee, Consulting/Advisory role: Eli Lilly; Advisory/Consultancy, Non-remunerated activity/ies, Educational, Lecture fee, Consulting/Advisory role: AstraZeneca; Research grant/Funding (self), Lecture fee: A&D Pharma; Honoraria (self): Clovis; Advisory/Consultancy, Travel/Accommodation/Expenses: Genekor; Honoraria (self), Advisory/Consultancy, Lecture fee, Honoraria, Advisory role: Novartis; Advisory/Consultancy, Travel/Accommodation/Expenses, Lecture fee, Advisory, Travel, Educational: Pfizer; Honoraria (self), Honoraria (institution), Advisory/Consultancy, Research grant/Funding (self), Travel/Accommodation/Expenses, Lecture fee, Honoraria, Travel, Educational: Roche; Honoraria (self): Samsung Bioepis. M. Campone: Honoraria (institution), Advisory/Consultancy, Consulting/advisory/fees to the Institution: AstraZeneca, Sanofi, Servier, AbbVie, Accord, Pfizer, Seagen; Advisory/Consultancy: Daiichi Sankyo; Honoraria (self), Advisory/Consultancy: Eli Lilly; Advisory/Consultancy, Speaker Bureau/Expert testimony: Novartis; Advisory/Consultancy: GT1. All other authors have declared no conflicts of interest.