CC Chemokine Family Members' Modulation as a Novel Approach for Treating Central Nervous System and Peripheral Nervous System Injury-A Review of Clinical and Experimental Findings

Despite significant progress in modern medicine and pharmacology, damage to the nervous system with various etiologies still poses a challenge to doctors and scientists. Injuries lead to neuroimmunological changes in the central nervous system (CNS), which may result in both secondary damage and the development of tactile and thermal hypersensitivity. In our review, based on the analysis of many experimental and clinical studies, we indicate that the mechanisms occurring both at the level of the brain after direct damage and at the level of the spinal cord after peripheral nerve damage have a common immunological basis. This suggests that there are opportunities for similar pharmacological therapeutic interventions in the damage of various etiologies. Experimental data indicate that after CNS/PNS damage, the levels of 16 among the 28 CC-family chemokines, i.e., CCL1, CCL2, CCL3, CCL4, CCL5, CCL6, CCL7, CCL8, CCL9, CCL11, CCL12, CCL17, CCL19, CCL20, CCL21, and CCL22, increase in the brain and/or spinal cord and have strong proinflammatory and/or pronociceptive effects. According to the available literature data, further investigation is still needed for understanding the role of the remaining chemokines, especially six of them which were found in humans but not in mice/rats, i.e., CCL13, CCL14, CCL15, CCL16, CCL18, and CCL23. Over the past several years, the results of studies in which available pharmacological tools were used indicated that blocking individual receptors, e.g., CCR1 (J113863 and BX513), CCR2 (RS504393, CCX872, INCB3344, and AZ889), CCR3 (SB328437), CCR4 (C021 and AZD-2098), and CCR5 (maraviroc, AZD-5672, and TAK-220), has beneficial effects after damage to both the CNS and PNS. Recently, experimental data have proved that blockades exerted by double antagonists CCR1/3 (UCB 35625) and CCR2/5 (cenicriviroc) have very good anti-inflammatory and antinociceptive effects. In addition, both single (J113863, RS504393, SB328437, C021, and maraviroc) and dual (cenicriviroc) chemokine receptor antagonists enhanced the analgesic effect of opioid drugs. This review will display the evidence that a multidirectional strategy based on the modulation of neuronal-glial-immune interactions can significantly improve the health of patients after CNS and PNS damage by changing the activity of chemokines belonging to the CC family. Moreover, in the case of pain, the combined administration of such antagonists with opioid drugs could reduce therapeutic doses and minimize the risk of complications.

Blockade of CCR5 suppresses paclitaxel-induced peripheral neuropathic pain caused by increased deoxycholic acid

Paclitaxel leads to peripheral neuropathy (paclitaxel-induced peripheral neuropathy [PIPN]) in approximately 50% of cancer patients. At present, there are no effective treatment strategies for PIPN, the mechanisms of which also remain unclear. In this study, we performed microbiome and metabolome analysis of feces and serum from breast cancer patients with different PIPN grades due to paclitaxel treatment. Our analysis reveals that levels of deoxycholic acid (DCA) are highly increased because of ingrowth of Clostridium species, which is associated with severe neuropathy. DCA, in turn, elevates serum level of C-C motif ligand 5 (CCL5) and induces CCL5 receptor 5 (CCR5) overexpression in dorsal root ganglion (DRG) through the bile acid receptor Takeda G-protein-coupled receptor 5 (TGR5), contributing to neuronal hyperexcitability. Consistent with this, administration of CCR5 antagonist maraviroc suppresses the development of neuropathic nociception. These results implicate gut microbiota/bile acids/CCR5 signaling in the induction of PIPN, thus suggesting a target for PIPN treatment.

Impact of antiretroviral therapy intensification with C-C motif chemokine receptor 5 antagonist maraviroc on HIV-associated neurocognitive impairment

OBJECTIVES

Chemokine receptor CCR5 is the principal co-receptor for entry of M-tropic HIV virus into immune cells. It is expressed in the central nervous system and may contribute to neuro-inflammation. The CCR5 antagonist maraviroc (MVC) has been suggested to improve HIV-associated neurocognitive impairment (NCI).

DESIGN

A double-blind, placebo-controlled, 48-week, randomized study of MVC vs. placebo in people with HIV (PWH) on stable antiretroviral therapy (ART) for more than one year in Hawaii and Puerto Rico with plasma HIV RNA less than 50 copies/ml and at least mild NCI defined as an overall or domain-specific neuropsychological z (NPZ) score less than -0.5.

METHODS

Study participants were randomized 2 : 1 to intensification of ART with MVC vs. placebo. The primary endpoint was change in global and domain-specific NPZ modeled from study entry to week 48. Covariate adjusted treatment comparisons of average changes in cognitive outcome were performed using winsorized NPZ data. Monocyte subset frequencies and chemokine expression as well as plasma biomarker levels were assessed.

RESULTS

Forty-nine participants were enrolled with 32 individuals randomized to MVC intensification and 17 to placebo. At baseline, worse NPZ scores were seen in the MVC arm. Comparison of 48-week NPZ change by arm revealed no differences except for a modest improvement in the Learning and Memory domain in the MVC arm, which did not survive multiplicity correction. No significant changes between arms were seen in immunologic parameters.

CONCLUSION

This randomized controlled study found no definitive evidence in favor of MVC intensification among PWH with mild cognitive difficulties.

Structural dynamics of chemokine receptors

Membrane proteins such as G protein-coupled receptors (GPCRs) are involved in awide range of physiological and pathological cellular processes. Binding of extracellular signals to GPCRs, including hormones, neurotransmitters, peptides and proteins, can activate intracellular signaling cascades via G protein interaction. Chemokine receptors are key GPCRs implicated in cancers, immune responses, cell migration and inflammation. Specifically, the CCR5 and CXCR4 chemokine receptors serve as important therapeutic targets against Human Immunodeficiency virus (HIV) entry into human cells. Maraviroc and Vicriviroc, two clinically used HIV entry inhibitors, are antagonists of the CCR5 receptor. These drugs block HIV entry, but ultimately resistance develops, due to emergence of viruses that can utilize the CXCR4 co-receptor. Unfortunately, development of chemokine receptor antagonists as selective drugs of HIV infection has been greatly hindered as their target orthosteric site is conserved among different receptor subtypes. Accordingly, it is important to understand the structural dynamics of these receptors to develop more effective therapeutics. In this chapter, we describe the latest advances in studies of these two key chemokine receptors with respect to their structures, dynamics and function.

Mass spectrometry imaging of hair identifies daily maraviroc adherence in HPTN 069/ACTG A5305

Objective measures of adherence for antiretrovirals used as pre-exposure prophylaxis (PrEP) are critical for improving preventative efficacy in both clinical trials and real-world application. Current objective adherence measures either reflect only recent behavior (eg days for plasma or urine) or cumulative behavior (eg months for dried blood spots). Here, we measured the accumulation of the antiretroviral drug maraviroc (MVC) in hair strands by infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging (MSI) to evaluate adherence behavior longitudinally at high temporal resolution. An MSI threshold for classifying daily adherence was established using clinical samples from healthy volunteers following directly observed dosing of 1 to 7 doses MVC/week. We then used the benchmarked MSI assay to classify adherence to MVC-based PrEP regimens in hair samples collected throughout the 48-week HPTN069/ACTGA5305 study. We found that only ~32% of investigated hair samples collected during the study's active dosing period showed consistent daily PrEP adherence throughout a retrospective period of 30 days, and also found that profiles of daily individual adherence from MSI hair analysis could identify when patients were and were not taking study drug. The assessment of adherence from MSI hair strand analysis was 62% lower than adherence classified using paired plasma samples, the latter of which may be influenced by white-coat adherence. These findings demonstrate the ability of MSI hair analysis to examine daily variability of adherence behavior over a longer-term measurement and offer the potential for longitudinal comparison with risk behavior to target patient-specific adherence interventions and improve outcomes.

Pharmacokinetics, the Immunological Impact, and the Effect on HIV Ex-Vivo Infectivity of Maraviroc, Raltegravir, and Lopinavir in Men Who Have Sex with Men Using Postexposure Prophylaxis

Most of the studies using the colorectal tissue explants challenge model have been conducted after one single dose and before reaching a steady state. We consider that longer exposure as in 28-day postexposure prophylaxis (PEP) course and in an at-risk setting, such as after a sexual risk exposure to HIV could give us valuable information about these drugs. In a substudy we assessed pharmacokinetics, changes on immune system and ex-vivo rectal mucosal susceptibility to HIV-1 infection after taking maraviroc (MVC), raltegravir (RAL), and ritonavir-boosted lopinavir (LPV/r) PEP-based regimens in 30 men who have sex with men. Participants received 28 days of twice-daily MVC (n = 11), RAL (n = 10) or LPV/r (n = 9) all with tenofovir/emtricitabine (TDF/FTC) backbone. Blood, rectal fluid, and rectal tissue samples were collected at days 7, 28, and 90 after starting PEP. The samples obtained at day 90 were considered baseline. All studied antiretrovirals were quantifiable at 7 and 28 days in all tissues. Activation markers were increased in CD4 mucosal mononuclear cells (MMCs) after 28 days of MVC: CD38 + 68.5 versus 85.1, p = .008 and CD38+DR +16.1 versus 26.7, p = .008. Exposure to MVC at both endpoints (7 and 28 days) was associated with significant suppression of HIV-1BAL (p = .005 and p = .028), but we did not observe this effect with RAL or LPV/r. Merging together changes in MMC in all arms, we found a positive correlation in the CD8 T cell lineage between the infectivity at day 7 and activation (CD38+ r = 0.43, p = .025, DR + r = 0.547, p = .003 and 38+DR+ r = 0.526, p = .05), senescence (CD57+CD28- r = 0.479, p = .012), naive cells (RA+CCR7+ r = 0.484, p = .01), and CCR5 expression (r = 0.593, p = .001). We conclude that MVC in combination with TDF/FTC was associated with viral suppression in rectal explants and that overall ex-vivo HIV infectivity correlated with activation and senescence in CD8 MMCs.

TGFβ1+CCR5+ neutrophil subset increases in bone marrow and causes age-related osteoporosis in male mice

TGFβ1 induces age-related bone loss by promoting degradation of TNF receptor-associated factor 3 (TRAF3), levels of which decrease in murine and human bone during aging. We report that a subset of neutrophils (TGFβ1+CCR5+) is the major source of TGFβ1 in murine bone. Their numbers are increased in bone marrow (BM) of aged wild-type mice and adult mice with TRAF3 conditionally deleted in mesenchymal progenitor cells (MPCs), associated with increased expression in BM of the chemokine, CCL5, suggesting that TRAF3 in MPCs limits TGFβ1+CCR5+ neutrophil numbers in BM of young mice. During aging, TGFβ1-induced TRAF3 degradation in MPCs promotes NF-κB-mediated expression of CCL5 by MPCs, associated with higher TGFβ1+CCR5+ neutrophil numbers in BM where they induce bone loss. TGFβ1+CCR5+ neutrophils decreased bone mass in male mice. The FDA-approved CCR5 antagonist, maraviroc, reduced TGFβ1+CCR5+ neutrophil numbers in BM and increased bone mass in aged mice. 15-mon-old mice with TGFβRII specifically deleted in MPCs had lower numbers of TGFβ1+CCR5+ neutrophils in BM and higher bone volume than wild-type littermates. We propose that pharmacologic reduction of TGFβ1+CCR5+ neutrophil numbers in BM could treat or prevent age-related osteoporosis.

Efficient removal of anti-HIV drug - maraviroc from natural water by peroxymonosulfate and TiO2 photocatalytic oxidation: Kinetic studies and identification of transformation products

In this study photochemical transformation of the antiretroviral pharmaceutical maraviroc under the simulated UV-Vis radiation was presented. The drug was shown to be extremely photo-resistant, with a half-life over 250 h, which is particularly significant, considering its presence in the aquatic environments. Addition of the natural river water matrix substantially increased the degradation rate, albeit the process led to formation of numerous phototransformation products. Due to high photostability and presumable environmental persistence of maraviroc, a photocatalytic method of its elimination was proposed. Although titanium dioxide alone presented acceptable results, its combination with peroxymonosulfate enormously accelerated the degradation process, increasing it over 67 000 times in comparison with the direct photolysis. Substitution of ultrapure water with river water resulted in inhibition of the PMS-driven processes, however the decomposition efficiency was still very high. Noteworthy, majority of the identified photoproducts were still present after termination of irradiation in all the experiments, which may indicate necessity of ecotoxicological assessment of those compounds.

Clinical evidence for a lack of cross-resistance between temsavir and ibalizumab or maraviroc

BACKGROUND

Temsavir (TMR), the active agent of the gp120-directed attachment inhibitor fostemsavir (FTR), the CD4-directed attachment inhibitor ibalizumab (IBA), and the CCR5 antagonist maraviroc (MVC) are antiretroviral agents that target steps in HIV-1 viral entry. Although mechanisms of inhibition of the three agents are different, it is important to understand whether there is potential for cross-resistance between these agents, as all involve interactions with gp120.

METHODS

Envelopes derived from plasma samples from participants in the BRIGHTE study who experienced protocol-derived virologic failure (PDVF) and were co-dosed with FTR and either IBA or MVC were analyzed for susceptibility to the agents. Also, CCR5-tropic MVC-resistant envelopes from the MOTIVATE trials were regenerated and studies were performed to understand whether susceptibility to multiple agents were linked.

RESULTS

The cloned envelopes exhibited reduced susceptibility to TMR and resistance to the co-dosed agent. At PDVF, emergent or preexisting amino acid substitutions were present at TMR positions of interest. When amino acid substitutions at these positions were reverted to the consensus sequence, full susceptibility to TMR was restored without effecting resistance to the co-dosed agent. In addition, five envelopes from MOTIVATE were regenerated and exhibited R5-tropic-MVC-resistance. Only one exhibited reduced susceptibility to TMR and it contained an M426L polymorphism. When reverted to 426M, full sensitivity for TMR was restored, but it remained MVC resistant.

CONCLUSION

The data confirm that decreased susceptibility to TMR and resistance to IBA or MVC are not linked and that there is no cross-resistance between either of these two agents and FTR.

Evaluation of the pharmacokinetic drug-drug interaction between the antiretroviral agents fostemsavir and maraviroc: a single-sequence crossover study in healthy participants

BACKGROUND

Fostemsavir is an oral prodrug of temsavir, a first-in-class attachment inhibitor that binds HIV-1 gp120, preventing initial HIV attachment and entry into host immune cells.

OBJECTIVE

The pharmacokinetic interaction was determined between temsavir and maraviroc, a CCR5 allosteric inhibitor indicated for CCR5-tropic HIV-1 that may be co-administered with fostemsavir as part of combination antiretroviral therapy in heavily treatment-experienced adults with multidrug-resistant HIV-1 infection.

METHODS

This was a Phase 1, open-label, single-sequence, 3-period crossover study evaluating the effect of fostemsavir on maraviroc pharmacokinetics and the effect of maraviroc on temsavir pharmacokinetics (ClinicalTrials.gov, NCT02480894). Fourteen healthy participants received fostemsavir 600 mg twice daily (BID) for 4 days in Period 1 (followed by a 3-day washout), maraviroc 300 mg BID for 5 days in Period 2, and fostemsavir 600 mg BID with maraviroc 300 mg BID for 7 days in Period 3. Study drugs were administered orally with a standard meal.

RESULTS

Following fostemsavir and maraviroc co-administration, maraviroc area under the plasma concentration-time curve over the dosing interval (AUC_τ) increased 25% (from 1914 to 2382 ng.h/mL) and maraviroc plasma concentration at the end of the dosing interval (C_trough) increased 37% (from 36.5 to 49.9 ng/mL), but there was no change in maximum observed concentration (C_max). Following fostemsavir and maraviroc co-administration, temsavir AUC_τ and C_max increased 10-13% and C_trough decreased 10%.

CONCLUSIONS

Co-administration of fostemsavir and maraviroc did not result in clinically relevant changes in maraviroc or temsavir exposure. Fostemsavir and maraviroc may be co-administered without dose adjustment of either antiretroviral agent.

[Potential application of maraviroc in the therapy of neuropathic pain]

According to International Association for the Study of Pain (IASP) neuropathic pain is defined as a pain caused by a lesion or disease of the somatosensory nervous system. In general population 7-8% adults suffer from chronic pain with neuropathic characteristic. The most common causes include: lumbar radiculopathy, postherpetic neuropathy, HIV infection, autoimmune diseases (multiple sclerosis), metabolic diseases (diabetic neuropathy), stroke or spinal cord injury. Current pharmacotherapy of neuropathic pain has insufficient effectiveness, so comprehension of neuropathic pain mechanism is necessary for research of new therapeutic methods. In the study we verify the analgesic effect of maraviroc (antagonist of the chemokine receptor - CCR5) and its potential role in the treatment of neuropathic pain. In the study we focused on dependency between opioid and chemokine receptors, because of similar structure between this receptors occurs cross-desensitization phenomenon. Chemokine antagonist maraviroc belongs to a group of entry inhibitors, antiretroviral drug. It enhances analgesic properties of opioids by inhibition of crossdesensitization of opioid's receptor. Application of maraviroc with morphine can reduce effective dosage of morphine 2,3 fold. Moreover, research show that prophylactic administration of maraviroc without opioid analgesics suppresses development of neuropathic pain symptoms. It has influence on glial phenotype, decreases secretion of proinflammatory cytokines and increases anti-inflammatory cytokine secretion. Furthermore it decreases expression of chemikine receptor mRNA and chemikine ligand's secreted by microglia and astrocytes as a result of nerve injury. We conclude that maraviroc has immunomodulatory properties, potentiates opioid analgesics effect, and can be used in neuropathic pain therapy as a potential co-analgesic.

Altered subcutaneous adipose tissue parameters after switching ART-controlled HIV+ patients to raltegravir/maraviroc

OBJECTIVE

To evaluate the effect on anthropometric, metabolic and adipose tissue parameters of switching ART-controlled persons living with HIV (PLWH) from a protease inhibitor regimen to raltegravir/maraviroc.

DESIGN

Sub-study of the ANRS157 ROCnRAL study with the investigation of subcutaneous abdominal adipose tissue (SCAT) biopsy at inclusion and study end.

METHODS

We performed lipoaspiration of paired SCAT samples, histology on fresh/fixed samples and examined the transcriptomic profile analyzed using Illumina microarrays after RNA extraction. Statistical analyses used the Wilcoxon-paired test.

RESULTS

The patients (n = 8) were mainly male (7/8), aged (mean ± standard error of the mean) 54.9 ± 1.2 years, BMI 26.1 ± 1.2 kg/m2, CD4+ 699 ± 56 cells/mm3, all viral load (VL) <50 copies/ml. After a follow-up of 6 ± 0.5 months, all PLWH remained with VL <50 copies/ml. BMI, trunk and limb fat amounts were unchanged yet systemic insulin resistance increased. Adipose tissue histology was unchanged except for borderline increased adipocyte diameter (P = 0.1). Among the 16 094 RNA transcripts, 458 genes were up-regulated and 244 were down-regulated. Analyses of the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology databases, evaluating modifications in the main functional pathways, revealed that genes related to immune recognition/function were less expressed as were genes encoding T-cell receptor and receptor signaling pathways. The gene expression profiles indicated decreased inflammation but genes involved in adipogenesis and insulin resistance were overexpressed.

CONCLUSION

After 6 months of raltegravir/maraviroc, adipogenesis-related gene profile was enhanced in SCAT, in agreement with a tendency for increased adipocyte size. Enhanced SCAT insulin resistance-related profile was concordant with higher systemic insulin resistance. However, the immune activation/inflammation profile was globally lowered. We propose that raltegravir/maraviroc might favor SCAT gain but reduce inflammation/immune activation.

Pharmacokinetics and safety of maraviroc in neonates

OBJECTIVE

The aim of this study was to evaluate safety and pharmacokinetics of maraviroc administered with standard antiretroviral prophylaxis to HIV-1 exposed infants and to determine the appropriate dose of maraviroc during the first 6 weeks of life.

DESIGN

A phase I, multicentre, open-label study enrolling two sequential cohorts.

METHODS

IMPAACT 2007 participants enrolled by day 3 of life and were stratified by exposure to maternal efavirenz. Cohort 1 participants received two single 8 mg/kg maraviroc doses 1 week apart with pharmacokinetic sampling after each dose. Cohort 2 participants received 8 mg/kg maraviroc twice daily through 6 weeks of life with pharmacokinetic sampling at weeks 1 and 4. Maraviroc exposure target was Cavg at least 75 ng/ml. Laboratory and clinical evaluations assessed safety.

RESULTS

Fifteen Cohort 1 and 32 Cohort 2 HIV-exposed neonates were enrolled (median gestational age 39 weeks, 51% male). All 13 evaluable Cohort 1 infants met the pharmacokinetic target. Median exposure for the 25 evaluable Cohort 2 infants met the pharmacokinetic target but variability was high, with 17-33% of infants below target at Weeks 1 and 4. Pharmacokinetic target achievement was similar between efavirenz exposure strata. No Grade 3+ toxicities, early study or treatment discontinuations due to maraviroc occurred.

CONCLUSION

Median maraviroc exposure met the Cavg target in neonates receiving 8 mg/kg twice daily, although exposures were variable. Maternal efavirenz use did not impact maraviroc exposure and no discontinuations were due to maraviroc toxicity/intolerance. No infants acquired HIV-1 infection during follow-up. Maraviroc 8 mg/kg twice daily appears well tolerated during the first 6 weeks of life.

Highly prevalent Russian HIV-1 V3-loop sequence variants are susceptible to maraviroc

INTRODUCTION

Maraviroc inhibits CCR5-tropic HIV-1 across different subtypes in vitro and has demonstrated efficacy in clinical trials. V3-loop amino acid variants observed in individual maraviroc-resistant viruses have not been found to be predictive of reduced susceptibility. Sequence-database searches have demonstrated that approximately 7.3% of viruses naturally encode these variants, raising concerns regarding potential pre-existing resistance. A study from Russia reported that combinations of these same amino acids are present in the V3 loops of the Russian variant subtype A (IDU-A, now A6) with a much greater prevalence (range: 74.4%-92.3%) depending on the combination. However, these studies and database searches did not include phenotypic evaluation.

METHODS

Sixteen Russian HIV-1 isolates (including sub-subtype A6 viruses) were assessed for V3 loop sequence and phenotypic susceptibility to maraviroc.

RESULTS

All 12 of the A6 viruses and 2/4 subtype B isolates encoded V3-loop variants that have previously been identified in individual virus isolates with reduced susceptibility to maraviroc. However, despite the prevalence of these V3-loop amino acid variants among the tested viruses, phenotypic sensitivity to maraviroc was observed in all instances. Similarly, reduced susceptibility to maraviroc was not found in virus from participants who experienced virologic failure in a clinical study of maraviroc in Russia (A4001101, [NCT01275625]).

DISCUSSION

Altogether, these data confirm that the presence of individual or combinations of V3-loop amino acid residues in sub-subtype A6 viruses alone does not predict natural resistance to maraviroc and that V3-loop genotype analysis of R5 virus prior to treatment is not helpful in predicting clinical outcome.

Switch to maraviroc with darunavir/r, both QD, in patients with suppressed HIV-1 was well tolerated but virologically inferior to standard antiretroviral therapy: 48-week results of a randomized trial

OBJECTIVES

Primary study outcome was absence of treatment failure (virological failure, VF, or treatment interruption) per protocol at week 48.

METHODS

Patients on 3-drug ART with stable HIV-1 RNA <50 copies/mL and CCR5-tropic virus were randomized 1:1 to maraviroc with darunavir/ritonavir qd (study arm) or continue current ART (continuation arm).

RESULTS

In June 2015, 115 patients were evaluable for the primary outcome (56 study, 59 continuation arm). The study was discontinued due to excess of VF in the study arm (7 cases, 12.5%, vs 0 in the continuation arm, p = 0.005). The proportion free of treatment failure was 73.2% in the study and 59.3% in the continuation arm. Two participants in the study and 10 in the continuation arm discontinued therapy due to adverse events (p = 0.030). At VF, no emergent drug resistance was detected. Co-receptor tropism switched to non-R5 in one patient. Patients with VF reported lower adherence and had lower plasma drug levels. Femoral bone mineral density was significantly improved in the study arm.

CONCLUSION

Switching to maraviroc with darunavir/ritonavir qd in virologically suppressed patients was associated with improved tolerability but was virologically inferior to 3-drug therapy.

Tissue Pharmacologic and Virologic Determinants of Duodenal and Rectal Gastrointestinal-Associated Lymphoid Tissue Immune Reconstitution in HIV-Infected Patients Initiating Antiretroviral Therapy

Plasma, duodenal, and rectal tissue antiretroviral therapy (ART) drug concentrations, human immunodeficiency virus (HIV) RNA and HIV DNA copy numbers, and recovery of mucosal immunity were measured before and 9 months after initiation of 3 different ART regimens in 26 subjects. Plasma and tissue HIV RNA correlated at baseline and when 9-month declines were compared, suggesting that these compartments are tightly associated. Antiretroviral tissue:blood penetration ratios were above the 50% inhibitory concentration values in almost 100% of cases. There were no correlations between drug concentrations and HIV DNA/RNA. Importantly, no evidence was found for residual viral replication or deficient tissue drug penetration to account for delayed gastrointestinal-associated lymphoid tissue immune recovery.

Strategic use of dual regimens of boosted protease inhibitors plus maraviroc in poorly adherent subjects in view of long-acting drugs: A retrospective study

In view of the forthcoming long-acting antiretrovirals, measures should be taken to prevent the selection of HIV drug resistance mutations. All subjects who had been switched to boosted protease inhibitors plus maraviroc (bPIs/MVC) with baseline HIV-1 RNA >50 copies/mL between June, 2014, and April, 2015, were retrospectively evaluated. HIV-1 RNA, CD4+ T-cells, serum glucose, creatinine, ALT, and adverse events were controlled every 3 to 4 months. We retrospectively analyzed 44 patients: 18 were taking darunavir/ritonavir (DRV/r) and 26 atazanavir/ritonavir (ATV/r) once daily, plus MVC 300 mg once daily. Seven subjects were in CDC stage C. All had a follow-up of at least 24 weeks, 28 exceeded 48 weeks, and 21 exceeded 72 weeks. All had experienced at least 1 viral failure and had selected at least 1 resistance-associated mutation (RAM). At baseline, 38 had plasma HIV-1 RNA 50-499 copies/mL and 6 had ≥500. At week 24, none had viremia >500 and 30 (68.2%) had suppressed HIV-1 RNA below 50 copies/mL. Of the subgroup with 48 weeks' follow-up, 23 had HIV-1 RNA 50-499 copies/mL, 5 had ≥500, and 20/28 suppressed to <50 copies/mL. Of the longest observed subgroup (72 weeks), 17 had HIV-1 RNA 50-499 copies/mL, and 4 had ≥500 copies/mL and 15/21 (71.4%) suppressed to <50 copies/mL. This combination allowed fair suppression of viral replication, with minor genotypic evolution in 6 subjects, and seems to be a feasible strategy to prevent damaging future options.

A randomized controlled clinical trial on the impact of CCR5 blockade with maraviroc in early infection on T-cell dynamics

BACKGROUND

Initiation of antiretroviral therapy (ART) in early HIV infection demonstrates clinical benefits including enhanced CD4 T-lymphocyte recovery and minimization of the latent HIV reservoir. Whether ART intensification with CCR5 blockade provides additional benefits is unknown.

TRIAL DESIGN

This randomized controlled trial evaluated the impact of maraviroc (MVC) intensification in persons starting ART in acute and early HIV (AEH, within 3 months of estimated date of infection).

METHODS

Twenty persons in AEH in San Diego underwent double-blind randomization to receive either standard of care (SOC) ART or SOC + MVC to evaluate the hypothesis that early CCR5 blockage with a CCR5-containing ART regimen may provide immunologic and clinical benefit. The primary outcome of this study was the difference from baseline to week 48 in the proportion of CCR5 CD4 memory T cells. Blood was drawn at baseline and weeks 12, 24, and 48 to evaluate CCR5 CD4 and CD8 T-cell dynamics using multicolor flow cytometry.

RESULTS

MVC intensification (n = 10) did not significantly alter CCR5 T-cell dynamics at week 48 of study compared to SOC (n = 9) in this fully recruited study (mean 1.12 vs 0.63, t = 0.36, df = 16, P = 0.727). Exploratory analyses of additional T-cell subsets suggest that MVC intensification in AEH trended to early greater increases in naïve and activated and proliferating CD4 T cells (P = 0.11, 0.19), and greater decreases in senescent memory CD4 T cells (P = 0.06), but these differences did not remain by week 48. CD8 T-cell evaluations did demonstrate trends to differences at week 48 with slower increases in naïve cells and slower decreases in activated memory cells (P = 0.16, 0.09). There were no reported harms or significantly different adverse events.

CONCLUSIONS

We did observe a few trends, but did not find compelling evidence that MVC intensification during AEH significantly impacts CD4 and CD8 T-cell dynamics. Diagnosing and starting persons in AEH on ART may be of greater clinical importance than the regimen initiated.

Maraviroc in addition to cART during primary HIV infection: Results from MAIN randomized clinical trial and 96-weeks follow-up

BACKGROUND

Multi-targeted treatment strategies including maraviroc (MVC) during Primary HIV Infection (PHI) may benefit from the immune-modulatory properties of this CCR5-inhibitor.

OBJECTIVES

We conducted a proof-of-concept clinical trial aimed at assessing whether maraviroc in addition of a combination antiretroviral therapy (cART) initiated during PHI would improve immunological and virological parameters.

STUDY DESIGN

The MAIN (Maraviroc in HIV Acute INfection) study was a randomized open-label clinical trial (EUDRACT number: 2008-007004-29) which enrolled 29 patients with PHI. Subjects were randomly assigned to receive cART-only (cART), cART+8 weeks of MVC (ST-MVC) or cART+48 weeks of MVC (LT-MVC), regardless of predicted co-receptor usage. After 48 weeks patients in ST-MVC and LT-MVC groups discontinued MVC. Patients were evaluated at week 48 and at week 96 of follow-up to assess differences in CD4 T-cell gain and plasma HIV-RNA.

RESULTS

Twenty-nine patients were enrolled. Seven patients (24%) had a predicted CXCR4 co-receptor usage. At week 48, 27 patients (93.1%) reached HIV-RNA<50cps/mL. Median CD4 T-cell count increase was 313 cells/μL (p<0.001, Wilcoxon signed-rank test). At multivariate linear regression analysis, LT-MVC arm had the greatest CD4 T-cell increase, while patients in ST-MVC arm had the least gain in CD4 T-cells (p=0.007). At week 96, multivariate analysis showed no associations between former treatment arm and CD4 T-cell gain.

CONCLUSIONS

The MAIN study showed that MVC for 48 weeks in addition to cART during PHI was able to enhance CD4 T-cell gain, regardless of co-receptor usage. After MVC discontinuation, the difference between treatment arms was lost.

Neurocognition with maraviroc compared with tenofovir in HIV

OBJECTIVE

The objective was to determine whether maraviroc (MVC) has unique neurocognitive benefits in the context of initial antiretroviral therapy (ART).

DESIGN

Randomized, double-blind, placebo-controlled, 48-week trial.

SETTING

Participants were enrolled in US AIDS Clinical Trials Group clinical trial sites.

PARTICIPANTS

Total 262 ART-naive, chemokine coreceptor 5 tropic HIV, and HIV RNA greater than 1000 copies/ml participants were randomized, 230 participants completed the study.

INTERVENTION

Participants received MVC 150 mg or tenofovir disoproxil fumarate (TDF) 300 mg on a background of ritonavir-boosted darunavir and emtricitabine.

MAIN OUTCOME MEASURE(S)

The neuropsychological battery of 15 tests done at baseline, week 24 and week 48 assessed seven domains, and were standardized into z-scores then converted into deficit scores and a global deficit score. The 48-week changes from baseline in the neuropsychological scores and the global deficit score were compared by Wilcoxon or Kruskal-Wallis test between arms, and among baseline impairment groups [classified as normal, mild (2 deficit scores ≥1) and moderate (2 deficit scores ≥2)]. It was hypothesized that the MVC arm would have improved neuropsychological performance over TDF.

RESULTS

In this double-blind, randomized, placebo-controlled trial, there were no differences in neuropsychological performance between MVC and TDF. Those with moderate neuropsychological impairment at baseline experienced greater ART-mediated neuropsychological improvement than those with mild or no neuropsychological impairment.

CONCLUSION

Improvement in neurocognitive functioning was greater with more baseline impairment but was comparable with MVC or TDF.

CCR5 blockade combined with cyclosporine A attenuates liver GVHD by impairing T cells function

OBJECTIVE

Our preview study found that CCR5 blockade combined with cyclosporine A could attenuate the severity of liver GVHD. But the potential immunological mechanisms have not yet been explored. So our present study was designed to clarify the potential immunological mechanisms in mouse models after allo-HSCT.

METHODS

Firstly, we detected donor T cells homing to target organs, and analyzed the specific effector subsets in liver. Additionally, we assessed antigen-presenting cells (APCs), especially DCs and CD4⁺ T cells differentiation in secondary lymphoid organs.

RESULTS

Data showed that MVC combined with CsA reduced donor T cells migration to target organs in vivo. MVC and CsA treatment reduced the amount of donor T cells in the absolute numbers, also in donor CD4⁺ and CD8⁺ T cells by targeting at CCR5. And MVC co-injected with CsA was capable of slightly suppressing DC maturation, and reduced the percentage of Th1 and Th17 mainly by noncompetitive combination of CCR5.

CONCLUSION

Combined use of MVC and CsA was effective in attenuating liver GVHD in murine model. It can suppress DC maturation, affect T cells differentiation, and reduce donor T cells homing to target organs. This may offer a novel therapeutic perspective approach for clinical liver GVHD after allo-HSCT.

Pharmacodynamic correlations using fresh and cryopreserved tissue following use of vaginal rings containing dapivirine and/or maraviroc in a randomized, placebo controlled trial

BACKGROUND

The ex vivo challenge assay is a bio-indicator of drug efficacy and was utilized in this randomized, placebo controlled trial as one of the exploratory endpoints. Fresh and cryopreserved tissues were evaluated for human immunodeficiency virus (HIV) infection and pharmacokinetic (PK)/pharmacodynamic (PD) relationships.

METHODS

HIV-negative women used vaginal rings containing 25 mg dapivirine (DPV)/100 mg maraviroc (MVC) (n = 12), DPV only (n = 12), MVC only (n = 12), or placebo (n = 12) for 28 days. Blood plasma, cervicovaginal fluid (CVF), and cervical biopsies were collected for drug quantification and the ex vivo challenge assay; half (fresh) were exposed immediately to HIV while the other half were cryopreserved, thawed, then exposed to HIV. HIV replication was monitored by p24 enzyme-linked immunosorbent assay from culture supernatant. Data were log-transformed and analyzed by linear least squared regression, nonlinear Emax dose-response model and Satterthwaite t test.

RESULTS

HIV replication was greater in fresh compared to cryopreserved tissue (P = 0.04). DPV was detected in all compartments, while MVC was consistently detected only in CVF. Significant negative correlations between p24 and DPV levels were observed in fresh cervical tissue (P = 0.01) and CVF (P = 0.03), but not plasma. CVF MVC levels showed a significant negative correlation with p24 levels (P = 0.03); drug levels in plasma and tissue were not correlated with HIV suppression. p24 levels from cryopreserved tissue did not correlate to either drug from any compartment.

CONCLUSION

Fresh tissue replicated HIV to greater levels and defined PK/PD relationships while cryopreserved tissue did not. The ex vivo challenge assay using fresh tissue could prioritize drugs being considered for HIV prevention.

48 week outcomes of maraviroc-containing regimens following the genotypic or Trofile assay in HIV-1 failing subjects: the OSCAR Study

This study assessed the 48-week efficacy of an antiretroviral therapy including maraviroc following the assessment of co-receptor tropism by use of Geno2Pheno algorithm or the Trofile phenotypic assay in failing treatment-experienced HIV-1 patients. This was a multicenter, randomized, open-label, non-inferiority trial. Treatment-experienced subjects with HIV-RNA ≥500 copies/mL were randomized (1:1) to undergo co-receptor tropism testing by the Geno- 2Pheno algorithm (with a false positive rate >10%) or the Trofile assay before starting a new antiretroviral treatment which included maraviroc. The primary endpoint was the 48 week proportion of patients with treatment success (TS). Intention-to-treat analyses are also reported. One hundred and fifty-five experienced patients were analysed: 77 patients in the Trofile arm and 78 in the Genotype arm. The 48-week proportion of TS was 87% in the Trofile arm and 89% in the Genotype arm (difference: 1.5%, 95%CI: -8.9% to 11.8%) suggesting non-inferiority. In the Trofile arm, 10 patients had treatment failure: 5 viral rebound, 5 discontinuations. In the Genotype arm, 9 patients had treatment failure: 7 viral rebound, 2 lost to follow-up. CD4+ significantly increased from baseline to week 48 in both arms. 48-week treatment success was similar for maraviroc-including therapy prescribed following the Trofile phenotypic assay or Geno2Pheno algorithm.

Biophysical characterization of small molecule antiviral-loaded nanolipogels for HIV-1 chemoprophylaxis and topical mucosal application

Nanocarriers are versatile vehicles for drug delivery, and emerging as platforms to formulate and deliver multiple classes of antiretroviral (ARV) drugs in a single system. Here we describe the fabrication of hydrogel-core and lipid-shell nanoparticles (nanolipogels) for the controlled loading and topical, vaginal delivery of maraviroc (MVC) and tenofovir disoproxil fumarate (TDF), two ARV drugs with different mechanisms of action that are used in the treatment of HIV. The nanolipogel platform was used to successfully formulate MVC and TDF, which produced ARV drug-loaded nanolipogels that were characterized for their physical properties and antiviral activity against HIV-1 BaL in cell culture. We also show that administration of these drug carriers topically to the vaginal mucosa in a murine model leads to antiviral activity against HIV-1 BaL in cervicovaginal lavages. Our results suggest that nanolipogel carriers are promising for the encapsulation and delivery of hydrophilic small molecule ARV drugs, and may expand the nanocarrier systems being investigated for HIV prevention or treatment.

STATEMENT OF SIGNIFICANCE

Topical, mucosal intervention of HIV is a leading strategy in the efforts to curb the spread of viral infection. A significant research thrust in the field has been to characterize different dosage forms for formulation of physicochemically diverse antiretroviral drugs. Nanocarriers have been used to formulate and deliver small molecule and protein drugs for a range of applications, including ARV drugs for HIV treatment. The broad significance of our work includes evaluation of lipid-shell, hydrogel-core nanoparticles for formulation and topical, vaginal delivery of two water-soluble antiretroviral drugs. We have characterized these nanocarriers for their physical properties and their biological activity against HIV-1 infection in vitro, and demonstrated the ability to deliver drug-loaded nanocarriers in vivo.

Tumoral Immune Cell Exploitation in Colorectal Cancer Metastases Can Be Targeted Effectively by Anti-CCR5 Therapy in Cancer Patients

The immune response influences the clinical course of colorectal cancer (CRC). Analyzing the invasive margin of human CRC liver metastases, we identified a mechanism of immune cell exploitation by tumor cells. While two distinct subsets of myeloid cells induce an influx of T cells into the invasive margin via CXCL9/CXCL10, CCL5 is produced by these T cells and stimulates pro-tumoral effects via CCR5. CCR5 blockade in patient-derived functional in vitro organotypic culture models showed a macrophage repolarization with anti-tumoral effects. These anti-tumoral effects were then confirmed in a phase I trial with a CCR5 antagonist in patients with liver metastases of advanced refractory CRC. Mitigation of tumor-promoting inflammation within the tumor tissue and objective tumor responses in CRC were observed.

Therapeutic Drug Monitoring of Anti-human Immunodeficiency Virus Drugs in a Patient with Short Bowel Syndrome

An elderly woman with human immunodeficiency virus-1 infection developed short bowel syndrome as a result of extensive intestinal resection. Considering the possibility of poor absorption of antiretroviral drugs (ARVs), therapeutic drug monitoring (TDM) was performed. A single-dose test of 6 ARVs (darunavir, ritonavir, lopinavir, etravirine, maraviroc, and raltegravir) did not provide information on the appropriate ARV, and repeated TDM under continuous antiretroviral therapy resulted in viral suppression below 50 copies/mL, which was considered to be treatment success. These assessments suggest the importance of TDM in the steady state for the successful treatment of individuals with impaired gastrointestinal function using ARVs.

Durability and Effectiveness of Maraviroc-Containing Regimens in HIV-1-Infected Individuals with Virological Failure in Routine Clinical Practice

INTRODUCTION

Limited data are available on the durability and effectiveness of maraviroc in routine clinical practice. We assessed the durability of maraviroc-containing regimens during a 30-month period, as well as their immunovirological and clinical efficacy, according to viral tropism in treatment-experienced individuals with viral load (VL) >50 copies/ml in the French Hospital Database on HIV.

METHODS

Virological success was defined as VL<50 copies/ml, immunological success as a confirmed increase of at least 100 CD4 cells/mm3 measured twice at least one month apart, and clinical failure as hospitalization for a non-AIDS event, an AIDS event, or death. Multivariable Cox regression models adjusted for potential confounders were used to assess the influence of viral tropism on durability, the immunovirological responses, and clinical outcome.

RESULTS

356 individuals started maraviroc with VL>50 copies/ml of whom 223 harbored R5 viruses, 44 non-R5 viruses and 89 viruses of unknown tropism. Individuals with non-R5 viruses were more likely than individuals with R5 viruses to discontinue maraviroc (75% vs 34%, p<0.0001). At 30 months, the estimated rates of virological and immunological success were respectively 89% and 51% in individuals with R5 viruses and 48% and 23% in individuals with non-R5 viruses. In multivariable analysis, non-R5 viruses were associated with a lower likelihood of both virological success (hazard ratio (HR): 0.42; 95% confidence interval (CI), 0.25-0.70) and immunological success (HR: 0.37; 95% CI, 0.18-0.77). No difference in clinical outcome was found between individuals with R5 and non-R5 viruses. The effectiveness of maraviroc-containing regimens in individuals with unknown viral tropism was not significantly different from that in individuals with R5 viruses. A limitation of the study is the absence of genotypic susceptibility score.

CONCLUSION

In this observational study, maraviroc-containing regimens yielded high rates of viral suppression and immunological responses in individuals with R5 viruses in whom prior regimens had failed.

[Companion Diagnostics for Selecting Antiretroviral Drugs against HIV-1]

Currently, the treatment of human immunodeficiency virus involves combination therapy, as antiretroviral therapy(ART). The treatment has improved steadily since the advent of potent combination therapy in 1996. New drugs that offer new mechanisms of action, improvements in potency and activity even against multidrug-resistant viruses, dosing convenience, and tolerability have been approved. Among ART with useful drugs, there are two important examinations before starting the treatment using the two kinds of drug. CCR5 co-receptor antagonists, maraviroc, prevent HIV entry into target cells by binding to CCR5 receptors. Genotypic assays have been developed that can determine or predict the co-receptor tropism(i.e., CCR5, CXCR4, or both) of the patient's dominant virus population. The assay for HIV-1 co-receptor usage should be performed whenever the use of a CCR5 antagonist is being considered. One of the nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), abacavir, is an important agent to develop recommended regimens for antiretroviral therapy. Serious and sometimes fatal hypersensitivity reactions have been associated with abacavir-containing products, ZIAGEN, Epzicom, and Triumeq. Patients who carry the HLA-B*5701 allele are at high-risk of a hypersensitivity reaction to abacavir. Prior to initiating therapy with abacavir, performing a screening test for the HLA-B*5701 allele is recommended. [Review].

Clinical outcome of maraviroc-containing therapy in heavily pre-treated HIV-1-infected patients

Available data on the use of maraviroc (MVC) in clinical settings are limited. In this cohort study, the clinical outcomes of HIV-1-infected patients treated with MVC were analysed and the predictive values of different tropism assays were compared. Baseline viral tropism was assessed and compared by phenotypic (Trofile and MT-2) and genotypic assays. Virological and immunological responses were evaluated. In total, 62 predominantly extensively pre-treated patients started MVC [median GSS 2.0 (IQR 2.0-2.5)]. Tropism assays were performed on baseline samples of 58 patients (93.5%). Thirty-two samples (80.0%) were classified as R5 by Trofile, 41 (80.4%) by genotypic tropism test (GTT) and 17 (81.0%) by MT-2. At least two types of tropism assay were performed on samples from 39 patients, whereas in 15 patients all three assays were performed (concordance 84.8-94.1%). Plasma HIV-RNA was <50 copies/mL in 82.1%, 85.0% and 68.8% of patients after 12, 24 and 36 months, respectively; median CD4 cell increase was 199 (IQR 108-283), 291 (IQR 187-413) and 234 (IQR 106-444)cells/μL. The predictive values of different tropism assays were comparably high: at Month 24, 92.9% (Trofile and GTT) and 100.0% (MT-2) of patients had plasma HIV-RNA <50 copies/mL. Three patients stopped MVC treatment because of suspected side effects. Five patients died during follow-up. In this heavily pre-treated cohort, treatment with MVC was well tolerated and resulted in good immunological and virological responses. Results generated by the different tropism assays correlated well with each other and had a high predictive value.

Missing CD4+ cell response in randomized clinical trials of maraviroc and dolutegravir

BACKGROUND

Missing data can compromise inferences from clinical trials, yet the topic has received little attention in the clinical trial community. Shortcomings in commonly used methods used to analyze studies with missing data (complete case, last- or baseline-observation carried forward) have been highlighted in a recent Food and Drug Administration-sponsored report. This report recommends how to mitigate the issues associated with missing data. We present an example of the proposed concepts using data from recent clinical trials.

METHODS

CD4+ cell count data from the previously reported SINGLE and MOTIVATE studies of dolutegravir and maraviroc were analyzed using a variety of statistical methods to explore the impact of missing data. Four methodologies were used: complete case analysis, simple imputation, mixed models for repeated measures, and multiple imputation. We compared the sensitivity of conclusions to the volume of missing data and to the assumptions underpinning each method.

RESULTS

Rates of missing data were greater in the MOTIVATE studies (35%-68% premature withdrawal) than in SINGLE (12%-20%). The sensitivity of results to assumptions about missing data was related to volume of missing data. Estimates of treatment differences by various analysis methods ranged across a 61 cells/mm3 window in MOTIVATE and a 22 cells/mm3 window in SINGLE.

CONCLUSIONS

Where missing data are anticipated, analyses require robust statistical and clinical debate of the necessary but unverifiable underlying statistical assumptions. Multiple imputation makes these assumptions transparent, can accommodate a broad range of scenarios, and is a natural analysis for clinical trials in HIV with missing data.

Cenicriviroc, a Novel CCR5 (R5) and CCR2 Antagonist, Shows In Vitro Activity against R5 Tropic HIV-2 Clinical Isolates

Background

Maraviroc activity against HIV-2, a virus naturally resistant to different HIV-1 antiretroviral drugs, has been recently demonstrated. The aim of this study was to assess HIV-2 susceptibility to cenicriviroc, a novel, once-daily, dual CCR5 and CCR2 antagonist that has completed Phase 2b development in HIV-1 infection.

Methods

Cenicriviroc phenotypic activity has been tested using a PBMC phenotypic susceptibility assay against four R5-, one X4- and one dual-tropic HIV-2 clinical primary isolates. All isolates were obtained by co-cultivation of PHA-activated PBMC from distinct HIV-2-infected CCR5-antagonist-naïve patients included in the French HIV-2 cohort and were previously tested for maraviroc susceptibility using the same protocol. HIV-2 tropism was determined by phenotypic assay using Ghost(3) cell lines.

Results

Regarding the 4 R5 HIV-2 clinical isolates tested, effective concentration 50% EC₅₀ for cenicriviroc were 0.03, 0.33, 0.45 and 0.98 nM, similar to those observed with maraviroc: 1.13, 0.58, 0.48 and 0.68 nM, respectively. Maximum percentages of inhibition (MPI) of cenicriviroc were 94, 94, 93 and 98%, similar to those observed with maraviroc (93, 90, 82, 100%, respectively). The dual- and X4-tropic HIV-2 strains were resistant to cenicriviroc with EC50 >1000 nM and MPI at 33% and 4%, respectively.

Conclusions

In this first study assessing HIV-2 susceptibility to cenicriviroc, we observed an in vitro activity against HIV-2 R5-tropic strains similar to that observed with maraviroc. Thus, cenicriviroc may offer a once-daily treatment opportunity in the limited therapeutic arsenal for HIV-2. Clinical studies are warranted.

Metastasis Suppressors Regulate the Tumor Microenvironment by Blocking Recruitment of Prometastatic Tumor-Associated Macrophages

Triple-negative breast cancer (TNBC) patients have the highest risk of recurrence and metastasis. Because they cannot be treated with targeted therapies, and many do not respond to chemotherapy, they represent a clinically underserved group. TNBC is characterized by reduced expression of metastasis suppressors such as Raf kinase inhibitory protein (RKIP), which inhibits tumor invasiveness. Mechanisms by which metastasis suppressors alter tumor cells are well characterized; however, their ability to regulate the tumor microenvironment and the importance of such regulation to metastasis suppression are incompletely understood. Here, we use species-specific RNA sequencing to show that RKIP expression in tumors markedly reduces the number and metastatic potential of infiltrating tumor-associated macrophages (TAM). TAMs isolated from nonmetastatic RKIP(+) tumors, relative to metastatic RKIP(-) tumors, exhibit a reduced ability to drive tumor cell invasion and decreased secretion of prometastatic factors, including PRGN, and shed TNFR2. RKIP regulates TAM recruitment by blocking HMGA2, resulting in reduced expression of numerous macrophage chemotactic factors, including CCL5. CCL5 overexpression in RKIP(+) tumors restores recruitment of prometastatic TAMs and intravasation, whereas treatment with the CCL5 receptor antagonist Maraviroc reduces TAM infiltration. These results highlight the importance of RKIP as a regulator of TAM recruitment through chemokines such as CCL5. The clinical significance of these interactions is underscored by our demonstration that a signature comprised of RKIP signaling and prometastatic TAM factors strikingly separates TNBC patients based on survival outcome. Collectively, our findings identify TAMs as a previously unsuspected mechanism by which the metastasis-suppressor RKIP regulates tumor invasiveness, and further suggest that TNBC patients with decreased RKIP activity and increased TAM infiltration may respond to macrophage-based therapeutics.

Maraviroc Intensification of cART in Patients with Suboptimal Immunological Recovery: A 48-Week, Placebo-Controlled Randomized Trial

OBJECTIVE

The immunomodulatory effects of the CCR5-antagonist maraviroc might be beneficial in patients with a suboptimal immunological response, but results of different cART (combination antiretroviral therapy) intensification studies are conflicting. Therefore, we performed a 48-week placebo-controlled trial to determine the effect of maraviroc intensification on CD4+ T-cell counts and immune activation in these patients.

DESIGN

Double-blind, placebo-controlled, randomized trial.

METHODS

Major inclusion criteria were 1. CD4+ T-cell count <350 cells/μL while at least two years on cART or CD4+ T-cell count <200 cells/μL while at least one year on cART, and 2. viral suppression for at least the previous 6 months. HIV-infected patients were randomized to add maraviroc (41 patients) or placebo (44 patients) to their cART regimen for 48 weeks. Changes in CD4+ T-cell counts (primary endpoint) and other immunological parameters were modeled using linear mixed effects models.

RESULTS

No significant differences for the modelled increase in CD4+ T-cell count (placebo 15.3 CD4+ T cells/μL (95% confidence interval (CI) [1.0, 29.5] versus maraviroc arm 22.9 CD4+ T cells/μL (95% CI [7.4, 38.5] p = 0.51) or alterations in the expression of markers for T-cell activation, proliferation and microbial translocation were found between the arms. However, maraviroc intensification did increase the percentage of CCR5 expressing CD4+ and CD8+ T-cells, and the plasma levels of the CCR5 ligand MIP-1β. In contrast, the percentage of ex-vivo apoptotic CD8+ and CD4+ T-cells decreased in the maraviroc arm.

CONCLUSIONS

Maraviroc intensification of cART did not increase CD4+ T-cell restoration or decrease immune activation as compared to placebo. However, ex-vivo T-cell apoptosis was decreased in the maraviroc arm.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00875368.

Lack of a significant pharmacokinetic interaction between maraviroc and tacrolimus in allogeneic HSCT recipients

OBJECTIVES

Emerging data suggest that the combination of tacrolimus and the CCR5 antagonist maraviroc, both cytochrome P450-3A4 substrates, may be effective in preventing graft-versus-host disease in patients undergoing allogeneic HSCT. This study evaluated whether a pharmacokinetic interaction exists between these agents.

METHODS

The study included 36 allogeneic HSCT recipients who received maraviroc + tacrolimus and 43 recipients of tacrolimus alone. We used a difference-in-differences analysis to examine the change in the concentration/dose ratios of tacrolimus after the discontinuation of maraviroc. In addition, we analysed the concentrations and dose requirements of tacrolimus in the two groups.

RESULTS

There was no significant difference in tacrolimus concentration/dose ratios in patients receiving maraviroc + tacrolimus compared with tacrolimus alone. Upon discontinuation of maraviroc, the change in concentration/dose ratio was small and not significant relative to the control group, and the effect estimate was further attenuated after adjustment for confounders [-0.35 (ng/mL)/(mg/day); P = 0.46]. In addition, the change in mean tacrolimus dose after discontinuation of maraviroc was similar between the groups (0.12 mg/day; P = 0.56), as was the change in mean tacrolimus concentration (0.02 ng/mL; P = 0.97).

CONCLUSIONS

Our findings do not support a significant inhibitory effect of maraviroc on the metabolism of tacrolimus. These data demonstrate that this drug combination is safe and imply that the protective effect of maraviroc against graft-versus-host disease was not mediated through an increase in tacrolimus concentrations. These findings are important for the design of clinical trials that evaluate maraviroc in combination with cytochrome P450-3A4 substrates.

Maraviroc Clinical Test (MCT) as an alternative tool to decide CCR5-antagonists prescription in naïve HIV-infected patients

Our aim was to analyze the virological response to a combined antiretroviral therapy started after Maraviroc Clinical Test (MCT) in naïve HIV-infected patients. Forty-one patients were exposed to MCT, based on an 8-day MVC monotherapy. If undetectability or a viral load reduction >1 log10 HIV-RNA copies/ml was achieved, a MVC-containing cART was prescribed. Forty patients showed a positive MCT; undetectability after 48weeks on cART was achieved in 34/41 (82.9%) patients. The result of MCT was compared with a genotypic tropism method and with Trofile®, showing 10.7% and 18.75% discordance rates, respectively. MCT is a reliable tool to decide CCR5-antagonists prescription, also in the naïve scenario where most patients show a virological response to MVC independently the tropism result reported by genotypic or phenotypic methods.

HIV-1 Coreceptor Usage Assessment by Ultra-Deep Pyrosequencing and Response to Maraviroc

Background

Maraviroc is an HIV entry inhibitor that alters the conformation of CCR5 and is poorly efficient in patients infected by viruses that use CXCR4 as an entry coreceptor. The goal of this study was to assess the capacity of ultra-deep pyrosequencing (UDPS) and different data analysis approaches to characterize HIV tropism at baseline and predict the therapeutic outcome on maraviroc treatment.

Methods

113 patients with detectable HIV-1 RNA on HAART were treated with maraviroc. The virological response was assessed at months 1, 3 and 6. The sequence of the HIV V3 loop was determined at baseline and prediction of maraviroc response by different software and interpretation algorithms was analyzed.

Results

UDPS followed by analysis with the Pyrotrop software or geno2pheno algorithm provided better prediction of the response to maraviroc than Sanger sequencing. We also found that the H34Y/S substitution in the V3 loop was the strongest individual predictor of maraviroc response, stronger than substitutions at positions 11 or 25 classically used in interpretation algorithms.

Conclusions

UDPS is a powerful tool that can be used with confidence to predict maraviroc response in HIV-1-infected patients. Improvement of the predictive value of interpretation algorithms is possible and our results suggest that adding the H34S/Y substitution would substantially improve the performance of the 11/25/charge rule.

Parameters Influencing Baseline HIV-1 Genotypic Tropism Testing Related to Clinical Outcome in Patients on Maraviroc

OBJECTIVES

We analysed the impact of different parameters on genotypic tropism testing related to clinical outcome prediction in 108 patients on maraviroc (MVC) treatment.

METHODS

87 RNA and 60 DNA samples were used. The viral tropism was predicted using the geno2pheno[coreceptor] and T-CUP tools with FPR cut-offs ranging from 1%-20%. Additionally, 27 RNA and 28 DNA samples were analysed in triplicate, 43 samples with the ESTA assay and 45 with next-generation sequencing. The influence of the genotypic susceptibility score (GSS) and 16 MVC-resistance mutations on clinical outcome was also studied.

RESULTS

Concordance between single-amplification testing compared to ESTA and to NGS was in the order of 80%. Concordance with NGS was higher at lower FPR cut-offs. Detection of baseline R5 viruses in RNA and DNA samples by all methods significantly correlated with treatment success, even with FPR cut-offs of 3.75%-7.5%. Triple amplification did not improve the prediction value but reduced the number of patients eligible for MVC. No influence of the GSS or MVC-resistance mutations but adherence to treatment, on the clinical outcome was detected.

CONCLUSIONS

Proviral DNA is valid to select candidates for MVC treatment. FPR cut-offs of 5%-7.5% and single amplification from RNA or DNA would assure a safe administration of MVC without excluding many patients who could benefit from this drug. In addition, the new prediction system T-CUP produced reliable results.

Safety, efficacy and indications of prescription of maraviroc in clinical practice: Factors associated with clinical outcomes

Maraviroc is approved for treatment-experienced HIV+ adults in twice-daily administration. Limited data are available on safety, efficacy and use in routine clinical practice, outside of restrictive clinical trials. This retrospective multicenter (27 centers) study included 667 subjects starting a regimen with maraviroc. The primary endpoint was plasma HIV-RNA <50copies/mL and CD4(+) cell count change at 48 and 96weeks (FDA snapshot analysis). 94.4% had CCR5 tropism (58.3% Trofile™, 29.2% population genotype, and 12% genotyping proviral DNA). Half of the subjects received the drug in scenarios or dosages outside the initial approval. Maraviroc was prescribed for salvage in 346 (51.9%) individuals, as a switch strategy due to toxicity in 135 (38.7%), for immune discordance in 75 (11.2%), and for simplification in 48 (7.2%). After salvage therapy, 223 (64.5%) subjects had HIV-RNA <50copies/mL at 48weeks, and 178 (51.4%) at 96weeks. Darunavir/r was included in 224 (64.7%) subjects and associated with higher rates of virological and immunologic efficacy (p<0.001). In multivariate analysis MSM (OR 2.25; 95%CI 1.29-3.94) and baseline HIV-RNA <100,000copies/mL (OR 1.96; 1.06-3.70) were associated with virological suppression. An increase in CD4(+) counts was seen at 48 and 96weeks in subjects with immune discordance (p<0.001). Maraviroc was used once-daily in 142 (21.3%) subjects overall, and 68 (57.4%) in switch/simplification. No new safety signals were identified. Besides in salvage regimens, maraviroc was frequently used in switch due to toxicity, simplification, and immune discordance. The efficacy in salvage in clinical practice was higher than in phase III clinical trials, likely due to availability of new active drugs in the regimen. These results increase our understanding of the efficacy, safety, and conditions of prescription of maraviroc beyond the initial registrational trials and the early manufacturer pharmacovigilance programs.

A prospective evaluation of maraviroc administration in patients with advanced HIV disease and multiple comorbidities: focus on efficacy and tolerability issues

In our HIV outpatient centre where over 1,200 patients are followed, maraviroc as an entry inhibitor was introduced in 2010. We aimed to assess the background, the therapeutic challenges and the prospective monitoring of all patients treated with a combination antiretroviral therapy (cART) including maraviroc. Sixty-six patients started a maraviroc-containing cART with a history of HIV infection lasting 13.9±10.7 years. This interim analysis presents patients who had at least 12 (mean 16.9±12.8) months of follow-up. One to 17 previous cART changes prompted the introduction of maraviroc in rescue regimens in the great majority of patients considered (53 of 66); in 13 cases, maraviroc was given to patients with advanced HIV disease and no immune recovery after 2-3 years of a virologically-effective cART. The most frequent companion antiretroviral agents were: darunavir/ritonavir (51 cases), raltegravir (49 subjects), and etravirine (36 cases). The most common underlying conditions were: AIDS (41 cases), liver cirrhosis (21), AIDS-related or other malignancies (20 cases), major cardiovascular events (18 cases), osteonecrosis and haemodialysis-treated kidney failure (3 cases each). A chronic HCV and HBV hepatitis were of concern in 25 and 13 patients. The addition of maraviroc added favourably to clinical-laboratory markers of HIV disease progression, and those of comorbid conditions. HIV viraemia became (or remained) undetectable in 55 patients of 66 (83.3%). An improvement in CD4+ count was observed in all 66 patients, based on a mean 24.9±19.2% increase versus baseline, paralleled by an improvement in mean absolute CD4+ count of 134.7±121.1 cells/μL. A tendency towards an increased mean and peak CD4+ count was observed in the subgroup receiving a maraviroc-raltegravir-based cART. As no clinical-laboratory adverse events attributable to maraviroc occurred, nobody discontinued the study drug. Only mild-transient gastrointestinal disturbances, fatigue and anorexia, were reported during maraviroc administration, but their relationship with the study drug was difficult to assess because of the multiple comorbidities and polypharmacy. Our preliminary experience with maraviroc, even considering the limits of the proportionally reduced sample, the patients' salvage stage of advanced disease and the related-unrelated morbidities, underlines its excellent efficacy and safety profile.

The maraviroc expanded access program - safety and efficacy data from an open-label study

PURPOSE

The maraviroc (MVC) expanded access program (EAP) was initiated to increase MVC availability to patients with limited treatment options. Darunavir (DRV), raltegravir (RAL), and etravirine (ETV) were either recently approved or under regulatory review at study initiation and available for coadministration with MVC. Thus, the safety of MVC in combination with new antiretroviral therapies (ARVs) could be assessed. This open-label safety study of MVC was conducted at 262 sites worldwide in 1032 R5 HIV-positive treatment-experienced patients with limited/no therapeutic options.

METHODS

Study visits included screening, baseline, end of study or early discontinuation, and follow-up 30 days after last dose. Interim visits for HIV-1 RNA and CD4 cell counts occurred according to local HIV infection management guidelines. Safety data were analyzed overall and by subgroup based on ARV combination [MVC+optimized background therapy (OBT), MVC ± OBT+DRV/r, MVC ± OBT+RAL, MVC ± OBT+RAL+DRV/r, MVC ± OBT+RAL+ETV ± DRV/r].

RESULTS

Most (90.3%) adverse events (AEs) were of mild or moderate severity with few grade 3/4 events, discontinuations, or temporary discontinuations/dose reductions due to AEs or serious AEs. Similar results were observed across subgroups. Of treated patients, 79.9% and 50% had HIV-1 RNA < 400 copies/ml and < 50 copies/ml respectively, at the end of the study, early termination visits, or at last known status. Tropism changes and selection of MVC-resistant R5 virus, including high-level MVC dependence, were mechanisms of viral escape.

CONCLUSION

MVC was well tolerated with virologic suppression observed in most patients.

Moving away from Ritonavir, Abacavir, Tenofovir, and Efavirenz (RATE)--agents that concern prescribers and patients: a feasibility study and call for a trial

Objectives

Regimens sparing RATE (ritonavir, abacavir, tenofovir, efavirienz) agents might have better long-term safety. We conducted a feasibility exercise to assess the potential for a randomised trial evaluating RATE-sparing regimens.

Design

Observational.

Methods

We first calculated RATE-sparing options available to an average patient receiving RATE agents. We reviewed treatment history and all resistance assays from patients attending the St. Vincent’s Hospital (Sydney) clinic and receiving ≥2 RATE agents (n = 120). A viable RATE-sparing regimen with 2 or 3 fully-active agents was constructed from the following six ‘safer’ agents: rilpivirine or etravirine; atazanavir; raltegravir; maraviroc; and lamivudine. Activity for each drug was predicted as 1 (full-activity), 0.5 or 0 (no activity) using the Stanford mutation database. The utility of maraviroc was calculated assuming both maraviroc activity and inactivity where unknown. The analysis was restricted to regimens for which supporting evidence was identified in the literature or conference proceedings. Finally, we calculated the proportion of patients in the nationally representative Australian HIV Observational Database (AHOD) cohort receiving ≥2 RATE agents (n = 1473) to measure the potential population-level uptake of RATE-sparing agents.

Results

Assuming full maraviroc activity, 117(97.5%) and 107(89.2%) individuals had at least one option with 2 or 3 active RATE-sparing agents, respectively. Assuming no maraviroc activity this decreased to 113(94.2%) and 104(86.7%), respectively. In AHOD, 837(56.8%) patients were receiving ≥2 RATE agents.

Conclusion

Feasible treatment switch options sparing RATE agents exist for the majority of patients. Understanding the pros and cons of switching stable patients onto new RATE-sparing regimens requires evidence derived from randomised controlled trials.

Molecular recognition of CCR5 by an HIV-1 gp120 V3 loop

The binding of protein HIV-1 gp120 to coreceptors CCR5 or CXCR4 is a key step of the HIV-1 entry to the host cell, and is predominantly mediated through the V3 loop fragment of HIV-1 gp120. In the present work, we delineate the molecular recognition of chemokine receptor CCR5 by a dual tropic HIV-1 gp120 V3 loop, using a comprehensive set of computational tools predominantly based on molecular dynamics simulations and free energy calculations. We report, what is to our knowledge, the first complete HIV-1 gp120 V3 loop : CCR5 complex structure, which includes the whole V3 loop and the N-terminus of CCR5, and exhibits exceptional agreement with previous experimental findings. The computationally derived structure sheds light into the functional role of HIV-1 gp120 V3 loop and CCR5 residues associated with the HIV-1 coreceptor activity, and provides insights into the HIV-1 coreceptor selectivity and the blocking mechanism of HIV-1 gp120 by maraviroc. By comparing the binding of the specific dual tropic HIV-1 gp120 V3 loop with CCR5 and CXCR4, we observe that the HIV-1 gp120 V3 loop residues 13-21, which include the tip, share nearly identical structural and energetic properties in complex with both coreceptors. This result paves the way for the design of dual CCR5/CXCR4 targeted peptides as novel potential anti-AIDS therapeutics.

Integrated computational tools for identification of CCR5 antagonists as potential HIV-1 entry inhibitors: homology modeling, virtual screening, molecular dynamics simulations and 3D QSAR analysis

Using integrated in-silico computational techniques, including homology modeling, structure-based and pharmacophore-based virtual screening, molecular dynamic simulations, per-residue energy decomposition analysis and atom-based 3D-QSAR analysis, we proposed ten novel compounds as potential CCR5-dependent HIV-1 entry inhibitors. Via validated docking calculations, binding free energies revealed that novel leads demonstrated better binding affinities with CCR5 compared to maraviroc, an FDA-approved HIV-1 entry inhibitor and in clinical use. Per-residue interaction energy decomposition analysis on the averaged MD structure showed that hydrophobic active residues Trp86, Tyr89 and Tyr108 contributed the most to inhibitor binding. The validated 3D-QSAR model showed a high cross-validated r_cv² value of 0.84 using three principal components and non-cross-validated r² value of 0.941. It was also revealed that almost all compounds in the test set and training set yielded a good predicted value. Information gained from this study could shed light on the activity of a new series of lead compounds as potential HIV entry inhibitors and serve as a powerful tool in the drug design and development machinery.

CCR5 inhibition prevents cardiac dysfunction in the SIV/macaque model of HIV

Background

Diastolic dysfunction is a highly prevalent cardiac abnormality in asymptomatic as well as ART‐treated human immunodeficiency virus (HIV) patients. Although the mechanisms underlying depressed cardiac function remain obscure, diastolic dysfunction in SIV‐infected rhesus macaques is highly correlated with myocardial viral load. As cardiomyocytes are not productively infected, damage may be an indirect process attributable to a combination of pro‐inflammatory mediators and viral proteins.

Methods and Results

Given the diverse roles of CCR5 in mediating recruitment of leukocytes to inflammatory sites and serving as a receptor for HIV entry into cells, we investigated the role of CCR5 in the SIV/macaque model of diastolic dysfunction. We found that in SIV‐infected macaques, CCR5 inhibition dramatically impacted myocardial viral load measured by qRT‐PCR and prevented diastolic dysfunction measured by echocardiography. Complementary in vitro experiments using fluorescence microscopy showed that CCR5 ligands impaired contractile function of isolated cardiomyocytes, thus identifying CCR5 signaling as a novel mediator of impaired cardiac mechanical function.

Conclusions

Together, these findings incriminate SIV/HIV gp120‐CCR5 as well as chemokine‐CCR5 interactions in HIV‐associated cardiac dysfunction. These findings also have important implications for the treatment of HIV‐infected individuals: in addition to antiviral properties and reduced chemokine‐mediated recruitment and activation of inflammatory cells, CCR5 inhibition may provide a cardioprotective benefit by preventing cardiomyocyte CCR5 signaling.

Four-year outcome of a PI and NRTI-sparing salvage regimen: maraviroc, raltegravir, etravirine

Aim of this study was to report the 204-week efficacy and safety results of a novel PI- and NRTI-sparing regimen for salvage therapy including maraviroc, raltegravir, etravirine in 28 failing HIV-infected patients with R5-tropic virus. The trend of laboratory parameters was tested by ANOVA for repeated measures and Greenhouse-Geisser probabilities were reported. Results were described as median (Q1-Q3) values. Twenty-six (93%) out of 28 patients completed 204 weeks of treatment. Virological success (HIV-RNA<50 copies/mL) at week 204 was 96%. CD4+ counts significantly increased [244 (158-213) cells/mm3, p<0.0001] from baseline [247 (68-355) cells/mm(3)] as well as CD4+ percentage. Four serious adverse events (1 death due to Hodgkins's lymphoma, 1 anal cancer, 1 Hodgkins's lymphoma, 1 recurrence of mycobacterial spondylodiscitis) were observed; three events led to transitory discontinuation of the antiretroviral therapy due to drug-drug interaction. BMI (p<0.0001) and waist circumference (p<0.0001) significantly increased over 204 weeks. An amelioration was also observed in relation to haemoglobin (p=0.0006), platelets (p<0.0001), white blood cell (p=0.013), neutrophils (p=0.301), lymphocytes (p=0.207) and creatinine (p<0.0001). In highly treatment-experienced patients the maraviroc, raltegravir and etravirine combination is associated with a good long-term efficacy and safety profile.

Extravirologic modulation of immune response by an NRTI-sparing antiretroviral regimen including darunavir and maraviroc

Dual therapies, including protease inhibitor + maraviroc (MVC), may represent an alternative to traditional regimens for management of HIV infection. The aim of this in vitro study was to assess the effects of darunavir (DRV) alone or in combination with MVC on cell apoptosis and chemotaxis. A significant decrease of cell apoptosis was found after DRV treatment. The addition of MVC to DRV also had an in vitro down-regulating effect on cell migration. The combination of an NRTI-sparing regimen including DRV+ MVC may have a potential role in immune system modulation by the direct down regulation of apoptosis and chemotaxis.