1. A phase Ib study of entinostat plus lapatinib with or without trastuzumab in patients with HER2-positive metastatic breast cancer that progressed during trastuzumab treatment
- Author
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Debu Tripathy, Ricardo H. Alvarez, Rashmi Krishna Murthy, Naoto T. Ueno, Carlos H. Barcenas, Jimin Wu, Jangsoon Lee, Richard Piekarz, Toshiaki Iwase, S. Jackson, Stacy L. Moulder, Sharon H. Giordano, Jeffrey A. Moscow, Abenaa M. Brewster, Vicente Valero, Darren W. Davis, Jie Willey, Nuhad K. Ibrahim, Yu Shen, Powel H. Brown, Bora Lim, and Daniel J. Booser
- Subjects
Adult ,Male ,Oncology ,Cancer Research ,medicine.medical_specialty ,Pyridines ,Receptor, ErbB-2 ,Breast Neoplasms ,Drug development ,Neutropenia ,Lapatinib ,Article ,Breast Neoplasms, Male ,Confirmatory trial ,03 medical and health sciences ,chemistry.chemical_compound ,Breast cancer ,0302 clinical medicine ,Trastuzumab ,Internal medicine ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Humans ,Neoplasm Metastasis ,skin and connective tissue diseases ,neoplasms ,Aged ,Dose-Response Relationship, Drug ,Entinostat ,business.industry ,Drug Synergism ,Middle Aged ,medicine.disease ,Metastatic breast cancer ,Survival Rate ,chemistry ,Tolerability ,Drug Resistance, Neoplasm ,030220 oncology & carcinogenesis ,Benzamides ,Female ,business ,medicine.drug - Abstract
Background Human epidermal growth factor 2 (HER2) is an effective therapeutic target in breast cancer; however, resistance to anti-HER2 agents such as trastuzumab and lapatinib develops. In a preclinical model, an HDAC inhibitor epigenetically reversed the resistance of cancer cells to trastuzumab and showed synergistic efficacy with lapatinib in inhibiting growth of trastuzumab-resistant HER2-positive (HER2+) breast cancer. Methods A phase 1b, dose escalation study was performed to assess maximum tolerated dose, safety/toxicity, clinical efficacy and explored pharmacodynamic biomarkers of response to entinostat combined with lapatinib with or without trastuzumab. Results The combination was safe. The MTD was lapatinib, 1000 mg daily; entinostat, 12 mg every other week; trastuzumab, 8 mg/kg followed by 6 mg/kg every 3 weeks. Adverse events included diarrhoea (89%), neutropenia (31%), and thrombocytopenia (23%). Neutropenia, thrombocytopenia and hypokalaemia were noted. Pharmacodynamic assessment did not yield conclusive results. Among 35 patients with evaluable response, PR was observed in 3 patients and CR in 3 patients, 1 maintained SD for over 6 months. Discussion This study identified the MTD of the entinostat, lapatinib, and trastuzumab combination that provided acceptable tolerability and anti-tumour activity in heavily pre-treated patients with HER2+ metastatic breast cancer, supporting a confirmatory trial.
- Published
- 2019