Despite the excellent efficacy of direct-acting antivirals (DAA) reported in clinical trials, virological failures can occur, often associated with the development of resistance-associated substitutions (RASs). This study aimed to characterize the presence of clinically relevant RASs to all classes in real-life DAA failures

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Natural resistance-associated substitutions (RASs) are reported with highly variable prevalence across different HCV genotypes (GTs). Frequency of natural RASs in a large Italian real-life cohort of patients infected with the 4 main HCV-GTs was investigated. NS3, NS5A and NS5B sequences were analysed in 1445 HCV-infected DAA-naïve patients. Sanger-sequencing was performed by home-made protocols on 464 GT1a, 585 GT1b, 92 GT2c, 199 GT3a, 16 GT4a and 99 GT4d samples. Overall, 20.7% (301/1455) of patients showed natural RASs, and the prevalence of multiclass-resistance was 7.3% (29/372 patients analysed). NS3-RASs were particularly common in GT1a and GT1b (45.2-10.8%, respectively), mainly due to 80K presence in GT1a (17%). Almost all GTs showed high prevalence of NS5A-RASs (range: 10.2–45.4%), and especially of 93H (5.1%). NS5A-RASs with fold-change >100x were detected in 6.8% GT1a (30H/R-31M-93C/H), 10.3% GT1b (31V-93H), 28.4% GT2c (28C-31M-93H), 8.5% GT3a (30K-93H), 45.5% GT4a (28M-30R-93H) and 3.8% GT4d (28V-30S-93H). Sofosbuvir RAS 282T was never detected, while the 159F and 316N RASs were found in GT1b (13.4–19.1%, respectively). Natural RASs are common in Italian patients infected with HCV-GTs 1–4. High prevalence of clinically-relevant RASs (such as Y93H) supports the appropriateness of HCV resistance-test to properly guide DAA-based therapy.

No abstract

Sofosbuvir/simeprevir plus a daily flat dose of RBV 800 mg for 12 weeks was highly effective and safe in genotype 1 elderly patients with compensated cirrhosis.

Even with newer DAA regimens, an integrated interpretation of clinical and virological pretreatment parameters, including natural RASs, may play a relevant role in bringing SVR rates close to the highest achievable. Treatment tailoring can be foreseen in 'hard-to-treat' patients, but also in 'easy' patients with favourable indicators, whereby a simplification/shortening of recommended regimens can be indicated.

Aim This study aimed to investigate the role of resistance‐associated substitutions (RASs) to direct‐acting‐antivirals (DAAs) in HCV genotype 3 (GT3). Methods Within the Italian VIRONET‐C network, a total of 539 GT3‐infected patients (417 DAA‐naïve and 135 DAA‐failures, of them, 13 at both baseline and failure) were analysed. Sanger sequencing of NS3/NS5A/NS5B was performed following home‐made protocols. Results The majority of patients were male (79.4%), 91.4% were injection drug users, 49.3% were cirrhotic and 13.9% were HIV co‐infected. Phylogenetic analysis classified sequences as GT3a‐b‐g‐h (98%‐0.4%‐0.2%‐1.2%) respectively. Overall, 135 patients failed a DAA regimen: sofosbuvir (SOF)/daclatasvir (DCV) or velpatasvir (VEL)±ribavirin (RBV) (N = 91/15) and glecaprevir (G)/pibrentasvir (P) (N = 9). Moreover, 14.8% of patients were treated with suboptimal regimens for GT3: 3D ± RBV (Paritaprevir/r + Ombitasvir+Dasabuvir, N = 15), SOF + Simeprevir (SIM) (N = 1) or SOF/Ledipasvir (LDV) ± RBV (N = 4). RAS prevalence was 15.8% in DAA‐naïve patients. At failure, 81.5% patients showed at least one RAS: 11/25 (44.0%) in NS3, 109/135 (80.7%) in NS5A, 7/111 (6.3%) in NS5B SOF‐failures. In NS5A‐failures, Y93H RAS was the most prevalent (68.5% vs 5.1% DAA‐naïve, P < .001) followed by A30K (12.7% vs 2.8% in DAA‐naïve, P < .001). Analysing baseline samples, a higher prevalence of NS5A‐RASs was observed before treatment in DAA‐failures (5/13, 38.5%) vs DAA‐naïves (61/393, 15.5%, P = .04). Regarding 228 DAA‐naïve patients with an available outcome, 93.9% achieved a SVR. Interestingly, patients with baseline Y93H and/or A30K had SVR rate of 72.2% vs 95.7% for patients without NS5A‐RASs (P = .002). Conclusions In this real‐life GT3 cohort, the majority of failures harboured resistant variants carrying NS5A‐RASs, the most frequent being Y93H. The presence of natural NS5A‐RASs before treatment was associated with failure. Further analyses are needed to confirm this observation, particularly for the new current regimens.

Background & Aims: Obeticholic acid (OCA) has recently been restricted in patients with primary biliary cholangitis (PBC) with "advanced cirrhosis" because of its narrow therapeutic index. We aimed to better define the predicting factors of hepatic serious adverse events (SAEs) and non-response in cirrhotic patients undergoing OCA therapy.Methods: Safety and efficacy of treatment were evaluated in a cohort of consecutive PBC cirrhotic patients started with OCA. OCA response was evaluated according to the Poise criteria. Risk factors for hepatic SAEs and non-response were reported as risk ratios (RR) with 95% confidence intervals (CIs).Results: One hundred PBC cirrhotics were included, 97 Child-Pugh class A and 3 class B. Thirty-one had oesophageal varices and 5 had a history of ascites. Thirty-three per cent and 32% of patients achieved a biochemical response at 6 and 12 months respectively. Male sex (adjusted-RR 1.75, 95%CI 1.42-2.12), INR (1.37, 1.00-1.87),