Tucatinib Combined With Ado-Trastuzumab Emtansine in Advanced ERBB2/HER2 -Positive Metastatic Breast Cancer
2018; American Medical Association; Volume: 4; Issue: 9 Linguagem: Inglês
10.1001/jamaoncol.2018.1812
ISSN2374-2445
AutoresVirginia F. Borges, Cristiano Ferrario, Nathalie Aucoin, Carla I. Falkson, Qamar J. Khan, Ian E. Krop, Stephen Welch, Alison Conlin, Jorge Chaves, Philippe L. Bédard, Marc C. Chamberlain, Todd Gray, Alex Vo, Erika Hamilton,
Tópico(s)Advanced Breast Cancer Therapies
ResumoImportance Treatment options for patients with disease progression after treatment with trastuzumab, pertuzumab, and ado-trastuzumab emtansine (T-DM1) are limited. Tucatinib is an oral, potent, human epidermal growth factor receptor 2 (HER2)-specific tyrosine kinase inhibitor (TKI) being developed as a novel treatment for ERBB2/HER2 -positive breast cancer. Objective To determine the maximum tolerated dosage of tucatinib in combination with T-DM1 in the treatment of patients with ERBB2/HER2 -positive metastatic breast cancer with and without brain metastases. Design, Setting, and Participants In this phase 1b open-label, multicenter, clinical trial, 57 participants enrolled between January 22, 2014, and June 22, 2015, were 18 years of age or older with ERBB2/HER2 -positive metastatic breast cancer previously treated with trastuzumab and a taxane. Data were analyzed between January and March 2018. Interventions Tucatinib 300 mg or 350 mg administered orally twice per day for 21 days and T-DM1 3.6 mg/kg administered intravenously once every 21 days. Main Outcomes and Measures Safety assessments, pharmacokinetics, and response were assessed using RECIST 1.1 every 2 cycles for 6 cycles, followed by every 3 cycles. Results Fifty-seven T-DM1-naive patients (median [IQR] 51 [44.0-63.0] years of age) who had undergone a median of 2 earlier HER2 therapies (range, 1-3) were treated. The tucatinib maximum tolerated dosage was determined to be 300 mg administered twice per day with dose-limiting toxic reactions seen at 350 mg twice per day. Pharmacokinetic analysis showed that there was no drug-drug interaction with T-DM1. Adverse events seen among the 50 patients treated at the maximum tolerated dosage regardless of causality included nausea (36 patients; 72%), diarrhea (30 patients; 60%), fatigue (28 patients; 56%), epistaxis (22 patients; 44%), headache (22 patients; 44%), vomiting (21 patients; 42%), constipation (21 patients; 42%), and decreased appetite (20 patients; 40%); the majority of adverse events were grade 1 or 2. Tucatinib-related toxic reactions that were grade 3 and above included thrombocytopenia (7 patients; 14%) and hepatic transaminitis (6 patients; 12%). Conclusions and Relevance In this study, tucatinib in combination with T-DM1 appeared to have acceptable toxicity and to show preliminary antitumor activity among heavily pretreated patients with ERBB2/HER2 -positive metastatic breast cancer with and without brain metastases. Trial Registration ClinicalTrials.gov Identifier:NCT01983501
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