1. Inhibiting Histone Deacetylase as a Means to Reverse Resistance to Angiogenesis Inhibitors: Phase I Study of Abexinostat Plus Pazopanib in Advanced Solid Tumor Malignancies.
- Author
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Aggarwal R, Thomas S, Pawlowska N, Bartelink I, Grabowsky J, Jahan T, Cripps A, Harb A, Leng J, Reinert A, Mastroserio I, Truong TG, Ryan CJ, and Munster PN
- Subjects
- Acetylation, Adult, Aged, Alanine Transaminase blood, Angiogenesis Inhibitors administration & dosage, Aspartate Aminotransferases blood, Benzofurans administration & dosage, Benzofurans blood, Benzofurans pharmacokinetics, Carcinoma, Renal Cell genetics, Disease Progression, Disease-Free Survival, Drug Resistance, Epigenesis, Genetic, Fatigue chemically induced, Female, Gene Expression, Histone Deacetylase 2 genetics, Histone Deacetylase Inhibitors administration & dosage, Histone Deacetylase Inhibitors blood, Histone Deacetylase Inhibitors pharmacokinetics, Histones metabolism, Humans, Hydroxamic Acids administration & dosage, Hydroxamic Acids blood, Hydroxamic Acids pharmacokinetics, Indazoles, Kidney Neoplasms genetics, Male, Maximum Tolerated Dose, Middle Aged, Neutropenia chemically induced, Pyrimidines administration & dosage, Sulfonamides administration & dosage, Thrombocytopenia chemically induced, Treatment Outcome, Vascular Endothelial Growth Factor A blood, Vascular Endothelial Growth Factor A genetics, Young Adult, Angiogenesis Inhibitors therapeutic use, Antineoplastic Combined Chemotherapy Protocols administration & dosage, Antineoplastic Combined Chemotherapy Protocols adverse effects, Carcinoma, Renal Cell drug therapy, Drug Resistance, Neoplasm drug effects, Kidney Neoplasms drug therapy
- Abstract
Purpose This phase I trial evaluated epigenetic modulation of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor by using a histone deacetylase abexinostat in combination with pazopanib to enhance response and reverse resistance. Patients and Methods Pazopanib was administered once a day on days 1 to 28 and abexinostat was administered orally twice a day on days 1 to 5, 8 to 12, and 15 to 19 (schedule A) or on days 1 to 4, 8 to 11, and 15 to 18 (schedule B). Dose escalation (3 + 3 design) in all solid tumors was followed by dose expansion in renal cell carcinoma (RCC). Results Fifty-one patients with RCC (N = 22) were enrolled, including 30 (59%) with one or more lines of prior VEGF-targeting therapy. Five dose-limiting toxicities, including fatigue (n = 2), thrombocytopenia (n = 2), and elevated AST/ALT (n = 1), were observed with schedule A; one dose-limiting toxicity was observed (elevated AST/ALT) was observed with schedule B. Grade ≥ 3 related adverse events included fatigue (16%), thrombocytopenia (16%), and neutropenia (10%). The recommended phase II dose was established as abexinostat 45 mg/m
2 twice a day administered per schedule B plus pazopanib 800 mg/d. Objective response rate was 21% overall and 27% in the RCC subset. Median duration of response was 9.1 months (1.2 to > 49 months). Eight patients (16%) had durable control of disease for > 12 months. Durable tumor regressions were observed in seven (70%) of 10 patients with pazopanib-refractory disease, including one patients with RCC with ongoing response > 3.5 years. Peripheral blood histone acetylation and HDAC2 gene expression were associated with durable response to treatment. Conclusion Abexinostat is well tolerated in combination with pazopanib, allowing prolonged exposure and promising durable responses in pazopanib- and other VEGF inhibitor-refractory tumors, which supports epigenetically mediated reversal of treatment resistance.- Published
- 2017
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