Pharmacokinetic study of dual therapy with raltegravir 400 mg twice daily and Darunavir/Ritonavir 800/100 mg once daily in HIV-1-infected patients

Dolutegravir impairs stem cell-based 3D morphogenesis models in a manner dependent on dose and timing of exposure: an implication for its developmental toxicity

Dolutegravir is an anti-retroviral drug of the integrase strand transfer inhibitor class used to treat HIV infection. It is the recommended first-line regimen for most people, including women of childbearing age. However, some human and animal studies have suggested that dolutegravir causes birth defects, although its developmental toxicity remains controversial. Here, we investigated the adverse effects of dolutegravir using pluripotent stem cell-based in vitro morphogenesis models that have previously been validated as effective tools to assess the developmental toxicity of various chemicals. Dolutegravir diminished the growth and axial elongation of the morphogenesis model of mouse pluripotent stem cells at exposures of 2 μM and above in a concentration-dependent manner. Concomitantly, dolutegravir altered the expression profiles of developmental regulator genes involved in embryonic patterning. The adverse effects were observed when the morphogenesis model was exposed to dolutegravir at early stages of development, but not at later stages. The potency and molecular impact of dolutegravir on the morphogenesis model were distinct from other integrase strand transfer inhibitors. Lastly, dolutegravir altered the growth and gene expression profiles of the morphogenesis model of human embryonic stem cells at 1 μM and above. These studies demonstrate that dolutegravir impairs morphological and molecular aspects of the in vitro morphogenesis models in a manner dependent on dose and timing of exposure through mechanisms that are unrelated to its action as an integrase strand transfer inhibitor. This finding will be useful for interpreting the conflicting outcomes regarding the developmental toxicity of dolutegravir in human and animal studies.

Targeted Mitochondrial COQ10 Delivery Attenuates Antiretroviral-Drug-Induced Senescence of Neural Progenitor Cells

HIV infection is associated with symptoms of accelerated or accentuated aging that are likely to be driven not only by HIV itself but also by the toxicity of long-term use of antiretroviral drugs. Therefore, it is crucially important to understand the mechanisms by which antiretroviral drugs may contribute to aging. The aim of this study was to investigate the hypothesis that antiretroviral drugs cause increased reactive oxygen species (ROS) generation that results in mitochondrial dysfunction and culminates in promoting cellular senescence. In addition, we applied targeted nanoparticle (NP)-based delivery to specifically enrich mitochondria with coenzyme Q₁₀ (CoQ₁₀) in order to enhance antioxidant protection. The studies employed neural progenitor cells (NPCs), as differentiation of these cells into mature neurons is affected both during HIV infection and in the aging process. Exposure of cultured NPCs to various combinations of HIV antiretroviral therapy (ART) induced a more than 2-fold increase in mitochondrial ROS generation and mitochondrial membrane potential, a more than 50% decrease in oxygen consumption and ATP levels, a 60% decrease in SIRT3 expression, and a 42% decrease in cell proliferation relative to control levels. These alterations were accompanied by a 37% increase in beta-galactosidase staining and a shortening of the telomere length to more than half of the length of controls as assessed by quantitative telomere-FISH labeling, indicating accelerated NPC senescence in response to ART exposure. Importantly, CoQ₁₀ delivered by targeted nanoparticles effectively attenuated these effects. Overall, these results indicate that ART promotes cellular senescence by causing mitochondrial dysfunction, which can be successfully reversed by supplementation with mitochondria-targeted CoQ₁₀.

Simplification of combination antiretroviral therapy (cART) and the brain-a real-life experience

Modern antiretroviral combination therapy (cART) has transformed HIV from a life-threatening infection into a chronic disease. However, the life-long treatment has side effects that frequently have a negative impact on patients' quality of life. Thus, there are some efforts to "simplify" therapy, i.e. apply regimens with three or fewer antiretroviral substances. However, neurologists are relatively sceptical towards this cART "simplification", because the capacity of simplified regimens to access the cerebrospinal fluid (CSF) might be too weak to effectively suppress viral load in this compartment. Thus, data of a big Neuro-AIDS cohort of 4992 HIV-positive patients consecutively recruited over three decades were retrospectively analysed in terms of neurocognitive performance of patients switched to simplified therapy regimens. To test whether simplified drug regimens result in new neuropsychological deficits or the worsening of pre-existing ones in HIV+ patients. Three groups of HIV+ patients were switched from triple therapy to three different two drug regimens (n = 177 to lamivudine/PI, n = 37 to INI/PI, and n = 303 to dual PI); three other groups of patients put from one to an alternative triple combination (n = 290 ABC/3TC/PI, n = 244 TDF/FTC/PI, and n = 158 TDF/FTC/NNRTI) for whatever reason served as controls. All patients were followed up over 4 years maximum. Every patient group improved immunologically and virologically after the switch. However, patients who switched to INI/PI combinations remained stable in neuropsychological tests, while a considerable percentage of patients who switched to other treatments demonstrated a decline. Remarkably, a high percentage of the patients switched to "simplified drug regimens" was not well-controlled virologically before the switch. HIV-positive patients with simplified therapy regimens show some benefit in terms of systemic infection surrogate markers (CD4 ± cell count and plasma viral load); however, neurocognitive deficits do not improve, but remain stable in most cases.

Dual Raltegravir-Darunavir/Ritonavir Combination in Virologically Suppressed HIV-1-Infected Patients on Antiretroviral Therapy Including a Ritonavir-Boosted Protease Inhibitor Plus Two Nucleoside/Nucleotide Reverse Transcriptase Inhibitors

BACKGROUND

Nucleoside reverse transcriptase inhibitor (NRTI)-sparing antiretroviral therapies may be useful in HIV-infected patients with resistance or intolerance to this class.

METHODS

We performed an observational study of patients on suppressive antiretroviral therapy containing two NRTIs plus one ritonavir-boosted protease inhibitor who switched to a dual regimen containing raltegravir (400 mg twice daily) and darunavir/ritonavir (800/100 mg once daily) and were followed-up for 48 weeks.

RESULTS

As a whole, 82 patients were enrolled. Mean duration of current regimen was 4.6 years and mean duration of plasma HIV RNA < 50 copies/mL before the switch was 46.2 months. Reason for simplification was toxicity in 76 patients and resistance to NRTIs in 13. After switching, the percentage of patients with HIV RNA < 50 copies/mL at week 48 was 92.7% in the intent-to-treat-exposed analysis and 97.6% in the per-protocol analysis. The switch led to a significant reduction in the mean triglyceride value (-85.2 mg/dL), in the prevalence of tubular proteinuria (-56%) and in the mean level of interleukin-6 (-0.94 pg/mL), with a significant increase in the mean phosphoremia (+0.58 mg/dL). Mean trough concentrations of both raltegravir and darunavir were within the therapeutic range. Two patients (2.4%) had virological failure due to suboptimal adherence and 4 subjects (4.9%) discontinued treatment due to adverse events, but no patients experienced Grade 3 or 4 adverse events.

CONCLUSION

In our study, simplification to a dual therapy containing raltegravir plus darunavir/ritonavir after 48 weeks maintained viral suppression in more than 90% of patients and showed a good tolerability with a favourable effect on proteinuria, ipophosphoremia, and lipid metabolism.