two drug regimens with dolutegravir plus rilpivirine or lamivudine in hiv 1 treatment naive virologically suppressed patients latest evidences from the literature on their efficacy and safety

Abstract Objectives In HIV-positive population, a paradigm shift from three-drug regimens to dolutegravir-based two-drug regimens as both initial and switch treatment approach is beginning to take place, virologically supported by the availability of new, potent drugs with high genetic-barrier that allow to overcome, at least in certain conditions, the dogma of three-drug regimens in HIV-effective therapy. Indeed, there is increasing evidence on their excellent and sustained long-term effectiveness and safety, that this manuscripts aims to review. Methods This review includes the most recent results on dolutegravir plus rilpivirine or lamivudine two-drug regimens from randomized clinical trials, meta-analyses and real-life studies, including relevant data presented at international conferences up to August 2019. Results As initial treatment strategy, dolutegravir plus lamivudine shows high efficacy and safety over 96 weeks in 1441 patients from GEMINI 1&2 phase III non-inferiority trials. In SWORD 1&2 trials, conducted in virologically suppressed patients, switching to once-daily dolutegravir plus rilpivirine maintained efficacy over 148 weeks; similarly, in TANGO trial no confirmed virological withdrawals were observed with dolutegravir/lamivudine through week 48. Consistent results were observed in real-life cohorts. No emergent dolutegravir-resistant virus has ever been reported in a patient in whom dolutegravir was prescribed in the context of such two-drug regimens. Switching to once-daily dolutegravir plus rilpivirine or lamivudine was generally well tolerated, and associated with favorable renal and bone safety. Conclusions The results so far available support dolutegravir-based two-drug regimens as excellent treatment options for adults with HIV-1 infection, either naive or already virologically-suppressed on their current antiretroviral regimen

Prolongation of incubation time improves clinical diagnosis of Mycobacterium xenopi infection and allows susceptibility testing of mycobacterial strains against multiple antibiotics.

Objectives: Mycobacterium xenopi is a nontuberculous mycobacterium (NTM) whose clinical diagnosis and drug susceptibility studies are frequently hampered by poor in vitro growth. Extending the culture incubation time from 42 days (common-standard) to 56 days could improve the likelihood of diagnosis and provide strains for phenotypic drug susceptibility profiling of this poorly studied but clinically relevant mycobacterium. Methods: Time-to-positivity of mycobacterial cultures incubated for 56 days were analysed and compared. Clinical mycobacteriosis was defined by ATS/IDSA criteria. In vitro susceptibility of M. xenopi isolates was tested by broth microdilution. Results: Of 3852 mycobacteria-positive cultures (26 different mycobacterial species),M. xenopi required by far the longest growth time in culture, exceeding the 42 days commonly used in routine diagnostics in 41.2% of cases versus 4.7% for other NTM and 2.0% for Mycobacterium tuberculosis complex (P < 0.001). Prolonging the incubation time to 56 days had a great impact on M. xenopi diagnosis, as 56.3% (27/48) of patients would have not fulfilled the ATS/IDSA criteria at an incubation limited to 42 days. All 40 M. xenopi isolates from patients with clinical mycobacteriosis were fully susceptibility to macrolides and rifamycins in vitro and to moxifloxacin, amikacin and linezolid. Conclusion: These results indicate that a significant percentage (56.3%) of positive culture forM. xenopi would have incorrectly been reported as negative to clinicians without prolonging the incubation time to 56 days. Moreover, 56.3% of patients with M. xenopi disease would have missed the diagnosis along with an appropriate germ-based antimycobacterial treatment, otherwise fully effective

The European Prevalence of Resistance Associated Substitutions among Direct Acting Antiviral Failures

Background: Approximately 71 million people are still in need of direct-acting antiviral agents (DAAs). To achieve the World Health Organization Hepatitis C elimination goals, insight into the prevalence and influence of resistance associated substitutions (RAS) is of importance. Collaboration is key since DAA failure is rare and real-life data are scattered. We have established a European collaboration, HepCare, to perform in-depth analysis regarding RAS prevalence, patterns, and multiclass occurrence. Methods: Data were extracted from the HepCare cohort of patients who previously failed DAA therapy. Geno-and subtypes were provided by submitters and mostly based on in-house assays. They were reassessed using the Comet HCV subtyping tool. We considered RAS to be relevant if they were associated with DAA failure in vivo previously reported in literature. Results: We analyzed 938 patients who failed DAA therapy from ten different European countries. There were 239 genotypes (GT) 1a, 380 GT1b, 19 GT2c, 205 GT3a, 14 GT4a, and 68 GT4d infections. Several unusual subtypes (n = 15) (GT1b/g/l, GT3b, GT4k/n/r/t) were present. RAS appeared in over 80% of failures and over a quarter had three or more RAS. Multiclass RAS varied over target region and genotype between 0-48%. RAS patterns such as the Q30R + L31M and Q30R + Y93H in GT1a, the L31V + Y93H and L31V + Y93H for GT1b, and A30K + L31M and A30K/V + Y93H for GT3a all occurred with a prevalence below 5%. Conclusion: RAS occur frequently after DAA failures and follow a specific genotype and drug related pattern. Interpretation of the influence of RAS on retreatment is challenging due to various patterns, patients' characteristics, and previous treatment history. Moving towards HCV elimination, an ongoing resistance surveillance is essential to track the presence of RAS, RAS patterns and gather data for a re-treatment algorithm

Improvement of ALT decay kinetics by all-oral HCV treatment: Role of NS5A inhibitors and differences with IFN-based regimens

Background: Intracellular HCV-RNA reduction is a proposed mechanism of action of direct-acting antivirals (DAAs), alternative to hepatocytes elimination by pegylated-interferon plus ribavirin (PR). We modeled ALT and HCV-RNA kinetics in cirrhotic patients treated with currently-used all-DAA combinations to evaluate their mode of action and cytotoxicity compared with telaprevir (TVR)+PR. Study design: Mathematical modeling of ALT and HCV-RNA kinetics was performed in 111 HCV-1 cirrhotic patients, 81 treated with all-DAA regimens and 30 with TVR+PR. Kinetic-models and Cox-analysis were used to assess determinants of ALT-decay and normalization. Results: HCV-RNA kinetics was biphasic, reflecting a mean effectiveness in blocking viral production &gt;99.8%. The first-phase of viral-decline was faster in patients receiving NS5A-inhibitors compared to TVR+PR or sofosbuvir+simeprevir (p&lt;0.001), reflecting higher efficacy in blocking assembly/secretion. The second-phase, noted \u3b4 and attributed to infected-cell loss, was faster in patients receiving TVR+PR or sofosbuvir+simeprevir compared to NS5A-inhibitors (0.27 vs 0.21 d-1, respectively, p = 0.0012). In contrast the rate of ALT-normalization, noted \u3bb, was slower in patients receiving TVR+PR or sofosbuvir+simeprevir compared to NS5A-inhibitors (0.17 vs 0.27 d-1, respectively, p&lt;0.001). There was no significant association between the second-phase of viral-decline and ALT normalization rate and, for a given level of viral reduction, ALT-normalization was more profound in patients receiving DAA, and NS5A in particular, than TVR+PR. Conclusions: Our data support a process of HCV-clearance by all-DAA regimens potentiated by NS5A-inhibitor, and less relying upon hepatocyte death than IFN-containing regimens. This may underline a process of "cell-cure" by DAAs, leading to a fast improvement of liver homeostasis

DECLINE OF PREVALENCE OF RESISTANCE ASSOCIATED SUBSTITUTIONS TO NS3 AND NS5A INHIBITORS AT DAA- FAILURE IN HEPATITIS C VIRUS IN ITALY OVER THE YEARS 2015 TO 2018

Background: A minority of patients fails to eliminate HCV and resistance-associated substitutions (RASs) are commonly detected at failure of interferon-free DAA regimens . Methods: Within the Italian network VIRONET-C, the prevalence of NS3/NS5A/NS5B RASs was retrospectively evaluated in patients who failed an EASL recommended DAA-regimen in 2015-2018 . The geno2pheno system and Sorbo MC et al. Drug Resistance Updates 2018 were used to infer HCV- genotype/subtype and predict drug resistance . The changes in prevalence of RASs over time were evaluated by chi-square test for trend, predictors of RASs at failure were analysed by logistic regression . Results: We included 386 HCV infected patients: 75% males, median age was 56 years (IQR 52-61), metavir fibrosis stage F4 in 76%; 106 (28%) were treatment- experienced: 91 (86%) with IFN-based treatments, 26 (25%) with DAAs. Patients with HIV and HBV coinfection were 10% (33/317) and 8% (6/72), respectively. HCV genotype was 1b in 122 pts (32%), 3 in 109 (28%), 1a in 97 (25%), 4 in 37 (10%), 2 in 21 (5%). DAA regimens were: LDV/SOF in 115 (30%), DCV/SOF in 103 (27%), 3D in 83 (21%), EBR/GRZ in 32 (8%), VEL/SOF in 29 (7%), GLE/PIB in 18 (5%) and 2D in 6 (2%); ribavirin was administered in 123 (32%) . The NS5A fasta-sequence was available for all patients, NS5B for 361 (94%), NS3 for 365 (95%) . According to the DAA failed the prevalence of any RASs was 90%, namely 80/135 (59%) in NS3, 313/359 (87%) in NS5A, 114/286 (40%) in NS5B . The prevalence of any RASs significantly declined from 2015 to 2018 (93% vs 70%, p=0.004): NS5A RASs from 90% to 72% (p=0 .29), NS3 RASs from 74% to 18% (p&lt;0 .001), while NS5B RASs remained stable . Independent predictors of any RASs included advanced fibrosis (AOR 6.1, CI 95% 1.8-20.3, p=0 .004) and genotype (G2 vs G1a AOR 0 .03, CI 95% 0 .002- 0 .31, p=0 .004; G3 vs G1a AOR 0 .08, CI 95% 0 .01-0 .62, p=0 .02; G4 vs G1a AOR 0 .05, CI 95% 0 .006-0 .46, p=0 .008), after adjusting for age, previous HCV treatment and year of genotype . Notably, full activity was predicted for GLE/PIB in 75% of cases and for at least two components of VEL/SOF/VOX in 53% of cases, no case with full-resistance to either regimen was found . Conclusion: Despite decreasing prevalence over the years, RASs remain common at virological failure of DAA treatment, particularly in patients with the highest grade of liver fibrosis. The identification of RASs after failure could play a crucial role in optimizing retreatment strategies

Genetic determinants in a critical domain of ns5a correlate with hepatocellular carcinoma in cirrhotic patients infected with hcv genotype 1b

HCV is an important cause of hepatocellular carcinoma (HCC). HCV NS5A domain‐1 interacts with cellular proteins inducing pro‐oncogenic pathways. Thus, we explore genetic variations in NS5A domain‐1 and their association with HCC, by analyzing 188 NS5A sequences from HCV genotype‐1b infected DAA‐naïve cirrhotic patients: 34 with HCC and 154 without HCC. Specific NS5A mutations significantly correlate with HCC: S3T (8.8% vs. 1.3%, p = 0.01), T122M (8.8% vs. 0.0%, p &lt; 0.001), M133I (20.6% vs. 3.9%, p &lt; 0.001), and Q181E (11.8% vs. 0.6%, p &lt; 0.001). By multivariable analysis, the presence of &gt;1 of them independently correlates with HCC (OR (95%CI): 21.8 (5.7–82.3); p &lt; 0.001). Focusing on HCC‐group, the presence of these mutations correlates with higher viremia (median (IQR): 5.7 (5.4–6.2) log IU/mL vs. 5.3 (4.4–5.6) log IU/mL, p = 0.02) and lower ALT (35 (30–71) vs. 83 (48–108) U/L, p = 0.004), suggesting a role in enhancing viral fitness without affecting necroinflammation. Notably, these mutations reside in NS5A regions known to interact with cellular proteins crucial for cell‐cycle regulation (p53, p85‐PIK3, and β‐ catenin), and introduce additional phosphorylation sites, a phenomenon known to ameliorate NS5A interaction with cellular proteins. Overall, these results provide a focus for further investigations on molecular bases of HCV‐mediated oncogenesis. The role of these NS5A domain‐1 mutations in triggering pro‐oncogenic stimuli that can persist also despite achievement of sustained virological response deserves further investigation

HCV genotypes are differently prone to the development of resistance to linear and macrocyclic protease inhibitors

Because of the extreme genetic variability of hepatitis C virus (HCV), we analyzed whether specific HCV-genotypes are differently prone to develop resistance to linear and macrocyclic protease-inhibitors (PIs)

HCV very late relapse following an atypical viral kinetics in a HIV patient treated for hepatitis C with direct-acting antivirals

Direct-acting antivirals (DAAs) for the treatment of HCV have dramatically increased the rate of sustained virological response: patients not achieving sustained virological response represent a challenge and rates of late recurrent viremia are very low. We describe here the first case of a very late HCV relapse, following an atypical kinetics (characterized by a spontaneous but transient HCV clearance after an early virological relapse), in a HIV co-infected patient treated with DAAs. Optimal adherence to the therapy was well documented and a phylogenetic analysis ruled out a possible reinfection from a different HCV strain. In conclusion, our case underlines the importance of a long follow-up (> 48 weeks) after DAAs therapies in HCV\u2013HIV co-infected patients who might benefit the most from a very rigorous virological surveillance

Founder effect of NS3 variant Q80K in HCV1a infected patients in Italy

Background: Italy is characterized by a high HCV burden, with higher prevalence rates in Southern and Insular areas compared to Central and Northern regions. Despite 95% success rates reported for all HCV genotypes with direct-acting antivirals (DAAs), eradication is hampered by the impact of natural resistance-associated variants (RAVs), especially in case of retreatment after DAA failure. This study aimed to investigate HCV1a variability within Italy, as well as the association of clusters with epidemiological factors and NS3 RAVs. Materials and methods: Between 2011 and 2015, 183 baseline NS3 sequences from serum samples of HCV1a infected patients were obtained with Sanger sequencing. Individuals were sampled in seven Italian regions (Abruzzo, Apulia, Emilia-Romagna, Lazio, Liguria, Lombardy and Sardinia). HCV1a control strains coding for protein NS3 and sequenced worldwide, were gathered from Genbank. A total dataset of 1084 sequences was obtained after subtyping, quality control and alignment. Sequences were annotated with RAVs using Geno2pheno, with year and country, and when available with gender, age, therapy status, transmission route and viral co-infection. Phylogenetic reconstruction was performed using RAxML, with GTR model and supported by 1000 bootstrap replicates. Clustering of sequences was identified with Cluster Picker, using 70% bootstrap support as threshold. Phylogenetic and temporal signal were determined with TreePuzzle and Path-O-Gen, after which clusters were confirmed using Bayesian phylogeny with BEAST. Results: Median age of the 183 HCV1a positive patients was 55 years (IQR: 50-66), with the majority being male (80.9%) and DAA naïve (89.1%). Transmission route was available for 61/183 patients (33%) and only 12/183 patients (7%) were co-infected with HIV. Based on a maximum-likelihood and Bayesian phylogenetic tree of the whole dataset, we identified two clusters, which included 3 patients from our cohort in total. The first cluster consisted of two DAA-naïve HCV mono-infected patients from Abruzzo (PP = 1). Both patients were male with one infected through intravenous drug use. For the second cluster (PP > 0.97), an HIV/HCV co-infected patient from Lazio clustered with an Italian control sequence, with for the latter lacking information for viral co-infections. Both sequences were derived from DAA-naïve patients with unknown transmission route. Remarkably, both clusters included patients all harbouring RAV Q80K. In depth-analysis showed a dispersion of the Italian sequences across the whole phylogenetic tree and a distinction of the tree into two major clades, with one consisting of all, except for one, sequences harbouring variant Q80K (n=96). Due to low support for the two separate clades, downsampling to 20% of the tree was performed multiple times, and this confirmed each time the existence of a founder effect for RAV Q80K. Conclusions: Phylogeny of HCV1a NS3 sequences identified two clusters among DAA-naïve Italian patients each harbouring RAV Q80K. All HCV1a sequences could be assigned to one of two major clusters, one with and one without Q80K. This founder effect of Q80K has implications for treatment of HCV1a cirrhotic patients with simeprevir and sofosbuvir, since Q80K is associated with lower success rates. Phylogenetic cluster analysis may aid in predicting treatment response and assessing viral evolution under DAA selective pressure.status: accepte