Prevalence of resistance-associated substitutions and retreatment of patients failing a glecaprevir/pibrentasvir regimen

OBJECTIVES

To investigate resistance-associated substitutions (RASs) as well as retreatment efficacies in a large cohort of European patients with failure of glecaprevir/pibrentasvir.

METHODS

Patients were identified from three European Resistance Reference centres in Spain, Italy and Germany. Sequencing of NS3, NS5A and NS5B was conducted and substitutions associated with resistance to direct antiviral agents were analysed. Clinical and virological parameters were documented retrospectively and retreatment efficacies were evaluated.

RESULTS

We evaluated 90 glecaprevir/pibrentasvir failures [3a (n = 36), 1a (n = 23), 2a/2c (n = 20), 1b (n = 10) and 4d (n = 1)]. Ten patients were cirrhotic, two had previous exposure to PEG-interferon and seven were coinfected with HIV; 80 had been treated for 8 weeks. Overall, 31 patients (34.4%) failed glecaprevir/pibrentasvir without any NS3 or NS5A RASs, 62.4% (53/85) showed RASs in NS5A, 15.6% (13/83) in NS3 and 10% (9/90) in both NS5A and NS3. Infection with HCV genotypes 1a and 3a was associated with a higher prevalence of NS5A RASs. Patients harbouring two (n = 34) or more (n = 8) RASs in NS5A were frequent. Retreatment was initiated in 56 patients, almost all (n = 52) with sofosbuvir/velpatasvir/voxilaprevir. The overall sustained virological response rate was 97.8% in patients with end-of-follow-up data available.

CONCLUSIONS

One-third of patients failed glecaprevir/pibrentasvir without resistance. RASs in NS5A were more prevalent than in NS3 and were frequently observed as dual and triple combination patterns, with a high impact on NS5A inhibitor activity, particularly in genotypes 1a and 3a. Retreatment of glecaprevir/pibrentasvir failures with sofosbuvir/velpatasvir/voxilaprevir achieved viral suppression across all genotypes.

Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.^1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.^4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.⁸ However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

PEPDar: A randomized prospective noninferiority study of ritonavir-boosted darunavir for HIV post-exposure prophylaxis

OBJECTIVES

PEPDar compared the tolerability and safety of ritonavir-boosted darunavir (DRV/r)-based post-exposure prophylaxis (PEP) with the tolerability and safety of standard of care (SOC). The primary endpoint was the early discontinuation rate among the per-protocol population.

METHODS

PEPDar was an open-label, randomized, multicentre, prospective, noninferiority safety study. Subjects were stratified by type of event (occupational vs. nonoccupational, i.e. sexual) and were randomized to receive DRV/r plus two nucleoside reverse transcriptase inhibitors (NRTIs) or SOC PEP. Twenty-two private or university HIV clinics in Germany participated. Subjects were ≥ 18 years old and had documented or potential HIV exposure and indication for HIV PEP. They initiated PEP not later than 72 h after the event and were HIV negative.

RESULTS

A total of 324 subjects were screened, the per-protocol population was 305, and 273 subjects completed the study. One hundred and fifty-five subjects received DRV/r-based PEP and 150 subjects received ritonavir-boosted lopinavir (LPV/r)-based PEP for 28-30 days; 298 subjects also received tenofovir/emtricitabine. The early discontinuation rate in the DRV/r arm was 6.5% compared with 10.0% in the SOC arm (P = 0.243). Adverse drug reactions (ADRs) were reported in 68% of DRV/r subjects and 75% of SOC subjects (P = 0.169). Fewer DRV/r subjects (16.1%) had at least one grade 2 or 3 ADR compared with SOC subjects (29.3%) (P = 0.006). All grades of diarrhoea, nausea, and sleep disorders were significantly less frequent with DRV/r, while headache was significantly more frequent. No HIV seroconversion was reported during follow-up.

CONCLUSIONS

Noninferiority of DRV/r to SOC was demonstrated. DRV/r should be included as a standard component of recommended regimens in PEP guidelines.

Treatment during primary HIV infection does not lower viral set point but improves CD4 lymphocytes in an observational cohort

Objective

To investigate if early treatment of primary HIV-1 infection (PHI) reduces viral set point and/or increases CD4 lymphocytes.

Methods

Analysis of two prospective multi-centre PHI cohorts. HIV-1 RNA and CD4 lymphocytes in patients with transient treatment were compared to those in untreated patients. Time to CD4 lymphocyte decrease below 350/μl after treatment stop or seroconversion was calculated using Kaplan-Meier and Cox-PH-regression analyses.

Results

156 cases of PHI were included, of which 100 had received transient HAART (median treatment time 9.5 months) and 56 remained untreated. Median viral load (563000 cop/ml vs 240000 cop/ml; p < 0.001) and median CD4 lymphocyte (449/μl vs. 613/μl; p < 0.01) differed significantly between treated and untreated patients. Median viral load was 38056 copies/ml in treated patients (12 months after treatment stop) and 52880 copies/ml in untreated patients (12 months after seroconversion; ns). Median CD4 lymphocyte change was +60/μl vs. -86/μl (p = 0.01). Median time until CD4 lymphocytes decreased to < 350/μl (including all patients with CD4 lymphocytes < 500/μl during seroconversion) was 20.7 months in treated patients after treatment stop and 8.3 months in untreated patents after seroconversion (p < 0.01). Cox-PH analyses adjusting for baseline VL, CD4 lymphocytes, stage of early infection and symptoms confirmed these differences.

Conclusions

Treatment during PHI did not lower viral set point. However, patients treated during seroconversion had an increase in CD4 lymphocytes, whereas untreated patients experienced a decrease in CD4 lymphocytes. Time until reaching CD4 lymphocytes < 350/μl was significantly shorter in untreated than in treated patients including patients with CD4 lymphocytes < 500/μl during seroconversion.

Safety of long-term lopinavir plasma-levels in patients with liver disease

Chronic liver disease is often found in HIV infected patients. LPV as first choice drug is often used over long time periods. TDM as a tool in patients care is important but the knowledge of LPV-plasma-levels in patients with chronic liver disease remain uncertain. With this retrosepective analysis we want to show if there are differences in LPV-plasma-levels between patients with and without chronic liver diseases over a long-time period. LPV-plasma-levels were analysed with an HPLC-based methode. The LPV-plasma-levels over the time course in patients with chronic liver disease (n = 30) and patients without liver disease (n = 38) was evaluated. Liver function tests, CD4-cell count and HI-viral load was also correlated with liver disease. The LPV plasma-levels of n = 450 samples from 30 patients with liver disease (Hepatitis B: n = 17, Hepatitis C: n = 16, Alcoholic liver disease: n = 7) were determined over 18.7 +/- 16,3 months (1 - 48.5 months). A median of 10 samples per patient was eligible (2 - 50 samples). There are no significant differences according to liver disease in LPV-plasma levels (mean Ctrough without: 5917 +/- 4811 ng/ml, mean Ctrough with liver-disease: 6564 +/- 4517 ng/ml, p > 0.05). The intraindividual and interindividual variation of LPV-plasma levels, CD-4 increase, HI-virus suppression and liver tests in patients with and without liver disease is comparable. In this clinical setting no differences in LPV-plasma levels between patients with and without chronic liver disease could be demonstrated. LPV-therapy in patients with chronic liver disease is therefore safe. In patients with impaired liver function TDM is a helpful tool for dose adjustment.