The histone deacetylase inhibitor panobinostat lowers biomarkers of cardiovascular risk and inflammation in HIV patients.

Abstract

To investigate the effect of the histone deacetylase inhibitor panobinostat on HIV-associated inflammation. Sub-study of a single-arm, phase I/II clinical trial. HIV-infected adults on suppressive antiretroviral therapy received oral panobinostat 20 mg three times per week, every other week, for 8 weeks, that is, four cycles of treatment. Plasma levels of high-sensitivity C-reactive protein, matrix metalloproteinase 9, soluble CD40 ligand and interleukin-6 were determined using human ELISA kits. Soluble endothelia selectin (E-selectin) was measured by a multiplex immunoassay. Total monocyte count, phenotype changes on monocytes and monocyte histone acetylation were analyzed using flow cytometry. Whole-genome expression in peripheral blood mononuclear cells was analyzed at baseline and on-panobinostat employing the Affymetrix Human Transcriptome Array 2.0 microarray assay. Changes from baseline were analyzed using Wilcoxon signed-rank test. For the gene-expression analyses, fold-changes, P values and false detection rate were computed using TAC software. Panobinostat treatment led to significant reductions in multiple established plasma markers of inflammation. Notably, high-sensitivity C-reactive protein decreased by a median of 58% during treatment and this change persisted for 4 weeks after treatment. Plasma levels of interleukin-6, matrix metalloproteinase 9, E-selectin and soluble CD40 ligand also significantly decreased on and/or postpanobinostat. Additionally, we observed a significant reduction in the proportions of intermediate monocytes and tissue factor-positive monocytes. This suppression of cardiovascular risk biomarkers was associated with a prominent reduction in the expression of genes related to inflammation and atherosclerosis. Collectively, these data indicate that panobinostat may have therapeutic potential to target excess inflammation in HIV patients with high cardiovascular risk.