Juan Tiraboschi

Maraviroc Concentrations in Cerebrospinal Fluid in HIV-Infected Patients

Objective:To determine maraviroc (MVC) concentrations in cerebrospinal fluid (CSF) in HIV-infected patients. Methods:Twelve CCR5+ HIV-1 adult antiretroviral-experienced patients receiving MVC-containing regimens for at least 1 month were enrolled. Both CSF and blood samples were taken around 12 hours after the last MVC dose. liquid chromatography tandem mass spectrometry was used to determine MVC concentrations, and HIV-1 viral load was determined by real-time polymerase chain reaction, (LOD, 40 copies/mL). Results:Twelve blood and 12 CSF samples were collected. Median CD4 count was 281(120-759) cells per microliter, and median HIV-1 viral load was <40 copies per milliliter. Median time on MVC was 13.5 weeks (4-60). Nucleoside analogues (tenofovir/didanosine) were given in only 1 case. Median MVC concentrations in plasma were 124.75 (7.3-517) ng/mL. In all except one, CSF sample-receiving an erroneous MVC dose while taking concomitantly nevirapine-MVC concentrations [2.58 (<0.5-7.22) ng/mL] were within the EC90 range (0.06-10.70). Median MVC CSF: plasma ratio was 0.022 (0.004-0.17), and when the free MVC plasma concentration was used, 0.094 (2.58-27.44). CSF viral load was <40 copies per milliliter in all 9 patients with undetectable plasma viral load. Conclusions:MVC achieves concentrations within the EC90 range in CSF. All patients with undetectable plasma viral load although receiving nucleoside-sparing regimens including new drugs showed viral suppression in CSF.

Etravirine concentrations in CSF in HIV-infected patients

OBJECTIVES To determine etravirine concentrations in CSF in HIV-infected patients. METHODS Twelve HIV-1 adult antiretroviral-experienced patients receiving an etravirine-containing regimen for at least 1 month were enrolled. Both CSF and blood samples were taken around 12 h after the last etravirine dose. Liquid chromatography-tandem mass spectrometry was used to determine etravirine concentrations, and HIV-1 viral load was determined by real-time PCR (limit of detection 40 copies/mL). RESULTS Twelve blood and 12 CSF samples were collected. The median CD4 count was 333 (84-765) cells/mm(3) and the median plasma HIV-1 viral load was <40 (range <40-1777) copies/mL. The median time on etravirine was 34 (range 4-140) weeks. The median etravirine concentration in plasma was 611.5 (range 148-991) ng/mL. The median CSF etravirine concentration was 7.24 (range 3.59-17.9) ng/mL; in all cases, values were above the IC(50) range (0.39-2.4 ng/mL). The median etravirine CSF:plasma ratio was 0.01 (range 0.005-0.03). The CSF viral load was >40 copies/mL in one patient and plasma viral load was still detectable after 4 weeks of therapy. CONCLUSIONS Etravirine achieves concentrations several times greater than the IC(50) range in CSF. All patients with undetectable plasma viral load were virologically suppressed in CSF while receiving an etravirine-containing regimen. Etravirine may help in controlling HIV-1 in CNS.

Effects on vitamin D, bone and the kidney of switching from fixed-dose tenofovir disoproxil fumarate/emtricitabine/efavirenz to darunavir/ritonavir monotherapy: a randomized, controlled trial (MIDAS).

BACKGROUND Efavirenz (EFV) has been associated with reductions in vitamin D (25[OH]D) and tenofovir (TDF) with increased bone turnover, reductions in bone mineral density (BMD) and renal tubular dysfunction. We hypothesized that switching from fixed-dose TDF/emtricitabine (FTC)/EFV to darunavir/ritonavir monotherapy (DRV/r) might increase 25(OH)D and BMD, and improve renal tubular function. METHODS Subjects with HIV RNA <50 copies/ml on TDF/FTC/EFV for ≥6 months were randomized 1:1 to ongoing TDF/FTC/EFV or DRV/r (800/100 mg once daily) for 48 weeks. The primary end point was change from baseline in 25(OH)D at week 48. Secondary end points included changes in BMD, bone turnover markers and renal tubular function. RESULTS A total of 64 subjects (86% male, 66% white, mean [sd] CD4(+) T-cell count 537.3 [191.5]/mm(3)) were analysed. After adjustment for baseline 25(OH)D and demographics, at week 48 DRV/r monotherapy was associated with a +3.6 (95% CI 0.6, 6.6) ng/ml increase in 25(OH)D compared to TDF/FTC/EFV (P=0.02). DRV/r monotherapy was associated with an increase in BMD (+2.9% versus -0.003% at the neck of femur and +2.6% versus +0.008% at the lumbar spine for DRV/r versus TDF/FTC/EFV; P<0.05 for all) and reductions in bone biomarkers compared with those remaining on TDF/FTC/EFV. No significant difference in renal tubular function was observed. Reasons for discontinuation in the DRV/r arm included side effects (n=4) and viral load rebound (n=3), all of which resolved with DRV/r discontinuation or regimen intensification. CONCLUSIONS Switching from TDF/FTC/EFV to DRV/r in patients with suppressed HIV RNA resulted in significant improvements in 25(OH)D and bone biomarkers, and a 2-3% increase in BMD.

Short communication: focal encephalitis related to viral escape and resistance emergence in cerebrospinal fluid in a patient on lopinavir/ritonavir monotherapy with plasma HIV-1 RNA suppression.

Abstract Monotherapy with boosted protease inhibitors has emerged as an antiretroviral therapy simplification alternative for selected patients, endorsed by the results of some randomized clinical trials. However, there are some concerns about the efficacy of such a strategy in achieving successful viral suppression in those anatomic compartments or reservoirs in which antiretroviral drug penetration is lower, such as the central nervous system (CNS). Several studies have demonstrated better neurocognitive performance in patients receiving antiretroviral drugs with better cerebrospinal fluid (CSF) penetration. Nevertheless, cases of CSF viral escape accompanied by moderate or severe neurological symptoms have been reported with both standard triple therapy and boosted protease inhibitor (PI) monotherapy, and it is not well established whether ritonavir-boosted protease inhibitor (PI/r) monotherapy is associated with a higher risk of symptomatic CSF viral escape or not. Herein, we present a case of viral r...Monotherapy with boosted protease inhibitors has emerged as an antiretroviral therapy simplification alternative for selected patients, endorsed by the results of some randomized clinical trials. However, there are some concerns about the efficacy of such a strategy in achieving successful viral suppression in those anatomic compartments or reservoirs in which antiretroviral drug penetration is lower, such as the central nervous system (CNS). Several studies have demonstrated better neurocognitive performance in patients receiving antiretroviral drugs with better cerebrospinal fluid (CSF) penetration. Nevertheless, cases of CSF viral escape accompanied by moderate or severe neurological symptoms have been reported with both standard triple therapy and boosted protease inhibitor (PI) monotherapy, and it is not well established whether ritonavir-boosted protease inhibitor (PI/r) monotherapy is associated with a higher risk of symptomatic CSF viral escape or not. Herein, we present a case of viral rebound and resistance emergence exclusively in CSF associated with an unusual clinical manifestation of focal encephalitis in a patient with plasma HIV-1 RNA suppression while receiving lopinavir/ritonavir monotherapy. Clinical resolution and CSF viral suppression were observed after switching to a genotype-guided combined antiretroviral regimen with good CSF penetration.

Maraviroc concentrations in seminal plasma in HIV-infected patients.

To the Editors: Maraviroc (MVC) is the first CCR5-antagonist approved for HIV treatment and has shown potent antiviral activity in HIV-infected patients with confirmed CCR5+ tropism. Little is known about its penetration and antiviral activity in viral reservoirs. The male genital tract can act as a separate compartment, in which different viral resistance patterns may develop, mainly in patients receiving drugs with suboptimal penetration. Good penetration of antiretroviral (ARV) drugs to the seminal plasma, a suggested surrogate male genital tract marker, could be associated with a decrease in viral replication and plays an important role in the prevention of sexual transmission of HIV. We present a series of HIV-infected ARV-experienced patientsdmost receiving an MVC-containing nucleosidesparing regimendin whom MVC concentrations and viral loads (VLs) were determined in blood plasma (BP) and seminal plasma (SP). MVC concentration in cerebrospinal fluid concentration was also assessed in some patients, and the results will be reported elsewhere. Eleven asymptomatic adult HIVinfected ARV-pretreated patients without clinical evidence of sexually transmitted disease were enrolled in our HIV outpatient unit. All had been taking MVC as part of an ARV regimen for at least 4 weeks. MVC dosage was set according to the recommendations stated in the European Medicines Agency’s scientific report. In each patient, plasma samples were obtained by peripheral venous puncture and semen samples by selfmasturbation. All samples were centrifuged and frozen at 70(C until analysis. Both blood and semen samples were taken the same day, approximately 12 hours after the previous MVC dose, to obtain the lowest BP MVC concentrations. The study was approved by the hospital ethics committee and the Spanish Drug Agency, and the patients gave written informed consent to participate. Total MVC concentrations in BP and SP samples were analyzed by a validated liquid chromatography tandem mass spectrometry assay (Tandem Labs, West Trenton, NJ; the ion transition monitored was 514.1/389.1) The reverse-phase chromatography calibration range was 0.5–500 ng/mL in Liheparin plasma samples. The extraction procedure is based on protein precipitation with acetonitrile, using 50 mL of plasma. The internal standard was the stable isotope label for MVC. HIV-1 VL was quantified with a real-time polymerase chain reaction technique (Abbott Molecular, Inc, Des Plaines, IL; limit of detection, 40 copies/mL). Patient mean age was 47 years. Median HIV-1 VL was <40 (<40–1777) copies per milliliter, and median CD4 count was 264 (120–810) cells per microliter. Patients were receiving MVC for a median of 5 (4–60) weeks. The pharmacokinetic data, virologic data, and ARV regimens received are summarized in Table 1. Raltegravir (RGV) was given in 90.9% of cases, darunavir in 54.5%, and etravirine in 36.3%. Only 2 patients received nucleoside analogues (TDF/ddI and TDF), and one other received nevirapine (NVP). According to the recommendations, this last patient should have received 300 mg twice a day of MVC in combination with RGV and NVP, but he erroneously took 150 mg twice a day. MVC BP and SP concentrations were determined in 13 samples from 11 patients. All MVC BP concentrations were above the minimal therapeutic concentration required to suppress HIV; the median value was 123 ng/mL (31.7– 529 ng/mL). In all SP samples, MVC concentrations exceeded several fold the median serum-adjusted EC90 of 0.57 ng/ mL (0.06–10.7 ng/mL). The median MVC SP concentration was 197 ng/mL (15.8–1650 ng/mL), and the median MVC SP:BP ratio was 0.89 (0.06–31.4). HIV-1 VL in SP was analyzed in 11 samples from 9 patients and was undetectable in 8 of them. BP VL was detectable in 3 of 9 patients, at levels of 1777, 202, and 99 copies per milliliter, respectively. Virologic response was adequate, with a 1.9–2.8 log VL reduction after 4, 4, and 5 weeks of MVC-including regimens, and in all 3 patients, SP VL was <40 copies per milliliter. On the other hand, 2 patients had detectable VL in SP while achieving BP suppression. One (patient 9) had been taking MVC for 58 weeks and had undetectable VL in SP in a subsequent sample. The other (patient 4; the NVP patient taking a suboptimal MVC dose) had the lowest MVC SP concentrations; VL was <40 copies per milliliter in a subsequent SP sample, despite a similar MVC SP concentration, but with a higher MVC BP concentration. In another patient (patient 6) with detectable SP VL, the semen sample was brought several weeks after a transient therapy discontinuation, and the results coincided with a parallel increase in BP VL. In this study, MVC BP concentrations in all patients were in the expected range; that is, several times higher than the median serum-adjusted EC90. MVC SP concentrations were higher than the upper end of the EC90 range in all patients. MVC reached a median SP concentration of 89% of the BP plasma concentration, suggesting that MVC diffuses passively from blood to the seminal compartment through the blood– testis barrier. Moreover, as MVC protein binding in semen seems to be low, at around 9% (4%–25%), the free MVC concentrations (active drug) in SP would be still several times above the EC90. We also found a very important interindividual variability in MVC plasma and semen concentrations. MVC is a substrate of CYP3A and also substrate of P-glycoprotein (PGP), and a concomitant use of CYP3A inhibitors and/or inducers with MVCmay alter the concentrations of this drug. Absorption and efflux from different compartments are influenced by the activity of PGP, which may be also altered by protease inhibitors. However, we could not find a statistically significant relationship between the concomitant use of MVC and CYP3A and/or PGP modifiers. Previous studies have demonstrated differing patterns of ARV drug penetration into male genital secretions: good concentrations with nucleoside analogues and nevirapine, varying with PIs, and lower with EFV. New

Brief Report: Pharmacokinetic/pharmacodynamic Investigation of Single-dose Oral Maraviroc in the Context of Hiv-1 Pre-exposure Prophylaxis

Abstract:To investigate the pharmacokinetics/pharmacodynamics of single-dose maraviroc 300 mg in HIV-1 exposure compartments. Maraviroc concentrations in blood, secretions (vaginal, urethral, oral, and rectal), and tissue (vaginal and rectal) were measured, and ex vivo challenge was performed in 54 healthy volunteers to study protection from HIV infection. Maraviroc Cmax occurred within 4 hours in most compartments. Concentrations from 4 to 72 hours were above intracellular (IC) IC90 in all compartments, range 15–8095 ng/mL. Mean AUC0-72 compartment-to-plasma ratios were highest in the rectum (45–819) and urethra (144) compared with the female genital tract (1.6–4.8) and saliva (0.2). No sex differences in AUC0-72 or Cmax were observed. No ex vivo protection from HIV-1BaL occurred in rectal or vaginal tissue. Despite high and sustained concentrations, single-dose maraviroc was not protective against ex vivo challenge of vaginal/rectal tissue.

Viral response in stable patients switching to fosamprenavir/ritonavir monotherapy (the FONT Study).

The aim of the study was to evaluate the efficacy of fosamprenavir/ritonavir (FPV/r) monotherapy in plasma and reservoirs in virologically suppressed patients.

Ability of treatment week 12 viral response to predict long-term outcome in genotype 1 hepatitis C virus/HIV coinfected patients.

Objective:Guidelines recommendation to extend treatment duration in genotype 1 hepatitis C virus (HCV)/HIV-coinfected patients who clear the virus later than treatment week 4 is not evidence-based. Our main objective was to study the ability of week 12 viral response [early virologic response (EVR)] to predict long-term outcome in patients treated for 48 weeks. Design:Multicenter retrospective cohort analysis. Methods:Genotype 1 HCV treatment-naive, HIV-coinfected adult patients with compensated liver disease who started combination therapy with fixed-dose pegylated-interferon (pegIFN) alfa-2a or weight-based pegIFN alfa-2b plus ribavirin were included. Univariate and forward stepwise logistic regression analysis were used to identify predictors of sustained viral response (SVR) and relapse. Results:By intention-to-treat analysis, 31.3% (87/278) of patients achieved an SVR. SVR rate was more than three-fold higher in patients who cleared the virus by week 12 of treatment compared with late responders. Among 123 end-of-treatment responders, 36 (29.3%) relapsed. Relapse risk increased in patients with cirrhosis, in those with ribavirin dose reductions and in late responders: more than 65% of patients who cleared the virus between weeks 12 and 24 relapsed following 48 weeks of treatment compared with 10% of those attaining a complete EVR (<15 IU/ml) at treatment week 12 (risk ratio 6.4, 95% confidence interval 2.9–14.4). Conclusion:Viral response at treatment week 12 is a strong predictor of long-term outcome. Genotype 1 HCV/HIV-coinfected patients who achieve a complete EVR (<15 IU/ml) are at low risk of viral relapse after completing the standard 48 weeks of therapy.

Effectiveness of efavirenz compared with ritonavir-boosted protease-inhibitor-based regimens as initial therapy for patients with plasma HIV-1 RNA above 100,000 copies/ml.

BACKGROUND There are no clinical trials in which the main objective is to compare the efficacy of efavirenz versus ritonavir-boosted protease inhibitor (PI/r)-based initial antiretroviral therapy (ART) in patients with high plasma HIV-1 RNA levels. This study aims to compare these regimens in this patient population in the setting of routine clinical practice. METHODS This was a multicentre, observational cohort study, including 596 consecutive treatment-naive patients with plasma HIV-1 RNA>100,000 copies/ml initiating efavirenz or PI/r-based ART between 2000 and 2010. The primary effectiveness end point was the percentage of patients with HIV-1 RNA<50 copies/ml at week 48 by intent-to-treat analysis. RESULTS Among a total of 596 patients, 57% initiated efavirenz and 43% PI/r-regimens (73% lopinavir and fosamprenavir [62% lopinavir, 11% fosamprenavir]). HIV-1 RNA suppression to <50 copies/ml at week 48 was higher in the efavirenz group (84% versus 74% [difference 10%, 95% CI 3.4%, 16.7%; P=0.002]). The percentage of virological failures was similar (efavirenz 4% versus PI/r 4%; P=0.686), but voluntary discontinuations and toxicity-related treatment changes were higher with PI/r (4% versus 1%; P=0.006 and 11% versus 6%; P=0.069, respectively). However, resistance selection at failure was higher in patients receiving efavirenz (89% versus 50%; P=0.203). Efavirenz was significantly more effective than lopinavir/r or fosamprenavir/r, whereas no significant differences were observed between efavirenz and darunavir/r or atazanavir/r. The high viral suppression in the efavirenz group was also evident in patients with very high viral loads (>500,000 copies/ml) and in those with low CD4(+) T-cell counts. CONCLUSIONS In routine clinical practice, the effectiveness of initial efavirenz-based regimens was at least similar to or even higher than various PI/r-based regimens in HIV-1-infected patients with plasma HIV-1 RNA>100,000 copies/ml.

Antiviral activity and CSF concentrations of 600/100 mg of darunavir/ritonavir once daily in HIV-1 patients with plasma viral suppression

OBJECTIVES The objective of this study was to assess whether a lower dose than the currently used one of darunavir/ritonavir might achieve good CSF concentrations and contribute to inhibition of CNS viral replication. PATIENTS AND METHODS This was a substudy of a randomized, open, multicentre study (eudraCT 2011-006272-39), comparing the efficacy and safety of 800/100 mg of darunavir/ritonavir (darunavir 800) versus 600/100 mg of darunavir/ritonavir (darunavir 600) once daily plus tenofovir/emtricitabine or abacavir/lamivudine in 100 virologically suppressed patients. Paired blood and CSF samples were obtained. Total plasma darunavir concentrations were determined by HPLC, and CSF concentrations by liquid chromatography-tandem MS. Viral load (VL) was determined in plasma and CSF (limit of detection = 40 copies/mL) by PCR. RESULTS Sixteen patients were enrolled. The median (range) of darunavir CSF concentrations in darunavir 600 (n = 8) and darunavir 800 (n = 8) patients was 17.08 (5.79-30.19) and 13.23 (3.47-32.98) ng/mL, respectively (P = 0.916). The median (range) darunavir CSF:plasma ratio was 0.010 (0.005-0.022) in darunavir 600 patients and 0.008 (0.004-0.017) in the darunavir 800 arm (P = 0.370). All 16 patients had a VL < 40 copies/mL in plasma and 14 had a VL < 40 copies/mL in CSF. Of the two patients with detectable CSF VL (280 copies/mL and 159 copies/mL), one was receiving darunavir 600 and the other darunavir 800 plus tenofovir/emtricitabine. Of note, these patients had the lowest CSF darunavir concentrations in their respective groups: 5.79 ng/mL (802 ng/mL in plasma) and 3.47 ng/mL (958 ng/mL in plasma). CONCLUSIONS Darunavir CSF and plasma concentrations were comparable between the two arms. However, one patient from each group (with the lowest CSF darunavir concentrations in their respective groups) had detectable CSF VL despite undetectable plasma VL.