Antiinflammatory effects of aprepitant coadministration with cART regimen containing ritonavir in HIV-infected adults

Abstract

Background: HIV-infected individuals, even well controlled with combined antiretroviral therapy (cART), have systemic inflammation and comorbidities. Substance P (SP) is an undecapeptide, which mediates neurotransmission and inflammation through its cognate neurokinin 1 receptor (NK1R). Plasma SP levels are elevated in HIV-infected individuals. The FDA-approved antiemetic aprepitant, an NK1R antagonist, has anti-HIV effects and antiinflammatory actions. We evaluated the safety, pharmacokinetics, and antiinflammatory properties of aprepitant in HIV-positive individuals receiving cART.

Methods: We conducted a phase 1B study of 12 HIV-positive individuals on a ritonavir-containing regimen (HIV viral load less than 40 copies/ml and CD4 > 400 cells/μl). Participants received open-label aprepitant 375 mg per day for 28 days and were followed for an additional 30 days. Changes in plasma levels of proinflammatory markers were assessed using flow cytometry, ELISA, luminex, and SOMAscan assays.

Results: The mean peak aprepitant plasma concentration was 30.7 ± 15.3 μg/ml at day 14 and 23.3 ± 12.3 μg/ml at day 28. Aprepitant treatment resulted in decreased plasma SP levels and affected 176 plasma proteins (56 after FDR) and several metabolic pathways, including inflammation and lipid metabolism. No change in soluble CD163 was observed. Aprepitant treatment was associated with a moderate increases in total and HDL cholesterol and affected select hematologic and metabolic markers, which returned to baseline levels 30 days after aprepitant treatment was stopped. There were 12 mild and 10 moderate adverse events (AE).

Conclusions: Aprepitant is safe and well tolerated. The antiinflammatory properties of aprepitant make it a possible adjunctive therapy for comorbid conditions associated with HIV infection.

Trial registration: ClinicalTrials.gov (NCT02154360).

Funding: This research was funded by NIH UO1 MH090325, P30 MH097488, and PO1 MH105303.

Figure 1. Consolidated Standards of Reporting Trials (CONSORT) diagram.

Figure 2. Plasma levels of aprepitant in patients receiving 375 mg dose per day.

Dose-exposure relationship. Eight-hour pharmacokinetic assessment was performed after the first dose (day 1) and at days 14 and 28 as indicated. In all cases, blood was drawn at 0.5, 1, 2, 4, and 8 hours after 375 mg oral dose of aprepitant. Mean (± SD) aprepitant plasma concentrations in 12 patients treated with drug are shown.

Figure 3. Changes in cholesterol levels associated with aprepitant treatment.

Total cholesterol, LDL, and HDL were measured by Quest Diagnostics. Results are presented as changes in cholesterol levels between day 0 and 14, day 0 and 28, or day 0 and 58 as indicated. Vertical bars are the widths of the 95% CI. P values by Wilcoxon signed-rank test are indicated.

Figure 4. Effect of substance P (SP) and aprepitant on lipid accumulation by human monocyte derived macrophages (MDM).

(A) Lipid accumulation by human macrophages. Human MDM were differentiated for 7 days in vitro as described in Methods. After incubation with acetylated LDL from human serum for 24 hours, cells were stained with Oil Red O stain. Lipid inclusions (red) are shown with arrows. Magnification, ×400. (B) Quantification of lipid accumulation by human MDM. Cholesterol [1,2-³H(N)] (1 μCi) was mixed with 50 μg of purified acetylated LDL from human serum, incubated for 30 minutes, and then added to MDM cultures and incubated for additional 24 hours. SP and aprepitant (Apr), 10 μM each, were added as indicated. Cells were washed with PBS and lysed with 10% Tween 20. ³H was measured in cell lysates using β-counter. The results are presented as individual values from 3 independent experiments, each done in duplicates. Vertical bars are mean ± SD. Each experiment is done with cells from different donors. Each condition is done in duplicates. *P < 0.05 by Student’s t test for SP-treated samples vs. not-treated control, vs. Apr, or vs. SP+Apr.

Figure 5. Changes in substance P (SP) levels associated with aprepitant treatment.

SP levels were determined as described in the Methods section. The results are presented as changes in SP levels between day 0 and 14, day 0 and 28, or day 0 and 58 as indicated. Vertical bars are the widths of the 95% CI. P values determined using Wilcoxon signed-rank test are indicated.

Figure 6. Protein interaction network for proteins that were affected by aprepitant administration.

Linear mixed effect modeling identified 176 proteins that changed their expression from baseline to day 28 after aprepitant treatment. The Reactome FIViz plugin of the Cytoscape software was used to identify metabolic pathways and plot a protein interaction network. Linker genes were included in the analysis. Linker genes and proteins that were not members of pathways in one of the 9 categories are hidden from view. (→) denotes activating or catalyzing functional interactions, (—|) denotes inhibiting interactions, (—) denotes proteins that are part of a complex or input, and (- - -) denotes predicted protein interactions.

Figure 7. Changes in selected individual proteins affected by aprepitant treatment.

Changes in plasma levels of individual proteins as a result of aprepitant treatment are shown. P values determined by 2-way ANOVA-FDR with the exception of IL-6, where P value is shown without the FDR adjustment. Changes in IL-6 levels are consistent with our previous studies (22).