Direct-Acting Antiviral Therapy for Patients with Chronic Hepatitis C Infection and Decompensated Cirrhosis

Patients with chronic hepatitis C virus (HCV) infection and decompensated cirrhosis are an important population for antiviral therapy yet under-represented in clinical trials. HCV direct-acting antiviral (DAA) therapies, unlike interferon-containing regimens, can be safely utilized in decompensated patients. Per guidelines from the American Association for the Study of Liver Diseases (AASLD), therapy of choice in HCV and decompensated cirrhosis is sofosbuvir, an HCV polymerase inhibitor, combined with a replication complex inhibitor (NS5A inhibitor) with or without ribavirin. Combination therapy with a HCV protease inhibitor and an NS5A inhibitor is effective in this population but is specifically not recommended in AASLD guidelines due to safety concerns. Important risk factors for further decompensation during DAA therapy are serum albumin < 3.5 g/dL, MELD (Model for End-Stage Liver Disease) score > 14, or HCV genotype 3 infection. Although sustained virologic response (SVR) is achieved less often in patients with decompensated vs compensated cirrhosis, in clinical studies response rates are > 80%. Both Child-Turcotte-Pugh Class at baseline and viral genotype can affect these response rates. Achieving SVR lowers risk of mortality, but to a lesser extent than in individuals with compensated cirrhosis. Likewise, treating patients for HCV infection along with successful treatment for hepatocellular carcinoma improves risks of both liver-related and overall mortality. In fewer than one third of cases, treating transplant-eligible, HCV-infected patients pre-transplant enables their delisting from transplant wait lists.

Vaccine-derived yellow fever in an immunocompromised patient on anti-CD20-antibody therapy and its treatment with sofosbuvir

Yellow fever (YF) is a potentially lethal viral hemorrhagic fever that can be prevented with the 17D live attenuated YF vaccine. However, this vaccination can cause severe adverse reactions including vaccine-associated YF. Here, we describe the case of a 32-year-old female who was permanently immunosuppressed with an anti-CD20 antibody due to multiple sclerosis. Following YF vaccination, the patient developed a variety of symptoms such as febrile temperatures, muscle and joint pain, headaches, and dysuria. A vaccine-associated YF with viremia was diagnosed. To avoid a potentially severe course of the disease, sofosbuvir was used as antiviral treatment followed by the resolution of symptoms and serological response. As travelers with chronic diseases and immunosuppression will increasingly engage in long distance travel, this case demonstrates the importance of assessing patient history prior to the administration of live vaccines and points towards a possible therapeutic approach in those suffering from vaccine-associated YF.

The deleterious effects of sofosbuvir and ribavirin (antiviral drugs against hepatitis C virus) on different body systems in male albino rats regarding reproductive, hematological, biochemical, hepatic, and renal profiles and histopathological changes

Sofosbuvir is one of the crucial drugs used in the treatment of chronic hepatitis C virus (HCV) in adults and children with compensated liver disease, including cirrhosis. It may be used alone or with other drugs. Ribavirin is an antiviral medication used to treat HCV infection. It is not effective when used alone and must be used in combination with other medications, such as sofosbuvir. This study pertains to a comprehensive assessment of the deleterious effects of sofosbuvir (an antiviral drug against chronic HCV) or sofosbuvir combined with ribavirin (an antiviral drug against RNA and DNA viruses) on several biological activities of the body, including hematological, hormonal, biochemical, histological, and immunohistochemical examinations during a long-standing period on male healthy rats. In addition, fertility assessments were performed, including sperm collections and semen parameter investigations. This study was conducted on 21 male rats divided into three equal groups. Group I (control group) received distilled water; group II (sofosbuvir group) received sofosbuvir (4 mg/kg); and group III (sofosbuvir + ribavirin) received sofosbuvir (4 mg/kg) plus ribavirin (30 ml/kg). All groups received the specific drug for six months. Blood and tissue samples were collected for hematological, hormonal, biochemical, histological, and immunohistochemical examinations. In addition, sperm collection and assessments of semen parameters were performed. Results revealed that sofosbuvir causes a highly significant decrease in the mean of most hematological, immunological, hormonal, and biochemical parameters, except for a few numbers of parameters such as neutrophils, monocytes, basophils, cortisol, GOT, and lipase, which exhibit a significant increase. The same occurred in the sofosbuvir + ribavirin group, but at much higher levels, as most hematological, immunological, hormonal, and biochemical parameters exhibit a highly significant decrease except for monocytes, triglyceride, and lipase, which exhibit a significant increase. When compared to the sofosbuvir group alone, the sofosbuvir + ribavirin group demonstrated a highly significant decline in the mean of most hematological, immunological, hormonal, and biochemical parameters except lymphocytes and triglycerides, which exhibit a substantial increase. For the reproductive parameters, both groups exhibit a significant decrease in the total sperm motility percentage. Finally, it can be concluded that sofosbuvir causes acute pancreatitis and combined immunodeficiency. Ribavirin is associated with hormonal deficiency, which indicates the occurrence of hypopituitarism. Moreover, sofosbuvir and ribavirin synergistically affect myelosuppression and cause iron-deficiency anemia. However, sofosbuvir, or its combination with ribavirin, is associated with a reduced risk of hepatocellular carcinoma. Besides, adding ribavirin to be combined with sofosbuvir improved the immunodeficiency caused by sofosbuvir; this confirms that using ribavirin with sofosbuvir reduces the side effects of both alone.

Carbonized aerogel/ZnO-based dispersive solid phase extraction of daclatasvir and sofosbuvir from biological samples prior to liquid chromatography-tandem mass spectrometry

Daclatasvir and sofosbuvir are antiviral medications utilized in the treatment of chronic hepatitis C virus (HCV) infection. Due to their low therapeutic index, careful monitoring is necessary to ensure that the optimal dose is administered. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) is an exceptionally sensitive and specific technique for quantifying these drugs within biological matrices. In this study, we developed a novel dispersive solid-phase extraction method employing a carbonized bio aerogel composite with ZnO for efficient extraction of daclatasvir and sofosbuvir from exhaled breath condensate, urine, and plasma samples. The extracted analytes were subsequently subjected to analysis using HPLC-MS/MS. Optimal parameters including pH adjustment, sorbent quantity variation, and elution solvent selection were fine-tuned to achieve maximum recovery efficiency while ensuring selectivity enhancements. The developed method demonstrated broad linearity ranging between 1.2 and 200 ng/mL along with good precision (relative standard deviations ≤6.2 %) and an acceptable coefficient of determination (r2 ≥0.994). These findings establish our proposed method as suitable for reliable drug quantification in clinical samples.

Serum MicroRNA profiles in chronic hepatitis C Egyptian patients before and after combined sofosbuvir and daclatasvir treatment

BACKGROUND

MicroRNAs (miR) are small sequence of nucleotides that can affect multiple genes involved in the hepatitis C virus (HCV) life cycle and disease development. The purpose of the present study was to investigate the clinical significance of serum microRNA profiles in a cohort of Egyptian patients with chronic HCV infection before and after combined sofosbuvir and daclatasvir treatment, as well as to gain a better understanding of the exact interaction mechanism in HCV transcriptional activity via differentially expressed miRNAs. For 12 weeks, 50 patients were eligible for and received sofosbuvir (400 mg daily) and daclatasvir (60 mg daily) treatment. Each patient's blood was obtained twice: once before therapy began and again three months afterwards.

RESULTS

The current study found that serum levels of circulating miR-122, miR-221, miR-23a, miR-125, miR-217, miR-224, and miR-181a were high in HCV pre-treatment patients, but after 12 weeks of direct-acting antiviral (DAAs) treatment, there was a statistically significant reduction in expression levels of miR-122, miR-221, miR-23a, miR-125, miR-217, and miR-224 (p < 0.001). There is no statistical significance for miR-181a.

CONCLUSION

The key differentially expressed microRNAs before and after the direct-acting antiviral (DAA) regimen were connected to the dynamics of chronic HCV infection, suggesting their potential as predictive biomarkers for HCV clearance after sofosbuvir and daclatasvir therapy.

Ledipasvir/Sofosbuvir in Hepatitis C Virus-Infected Children With Hematological Malignancies: A Pharmacokinetic Study

PURPOSE

Children with hematological malignancies and chronic hepatitis C virus (HCV) infection are at a higher risk for rapid progression of liver disease and malignancy relapse due to multiple hepatitis flares and chemotherapy interruption. They are therefore potential candidates for microelimination of HCV infection. This study aimed to assess the effect of acute lymphoblastic leukemia (ALL) on the pharmacokinetic (PK) profile of direct-acting antivirals, namely ledipasvir/sofosbuvir (LDV/SOF) and the SOF major metabolite GS-331007.

METHODS

This was a 24-week, prospective, controlled, open-label, 2-arm PK study of patients receiving 45/200 mg once-daily LDV/SOF orally for 12 weeks. Eligible patients were HCV-RNA-positive, treatment-naive children aged 6 to <12 years and/or weighing 17 to <35 kg with genotype 4 chronic HCV infection without cirrhosis. The primary efficacy and safety end points were the achievement of sustained virologic response for all patients with absence of any adverse events leading to permanent discontinuation of the study drug. Steady-state noncompartmental analysis was performed to determine the PK parameters of SOF, GS-331007, and LDV as the primary PK outcome. Dose suitability was based on the 90% CI of exposure geometric mean ratio percentage within 50% to 200% compared with adults.

FINDINGS

Ten HCV-infected children with ALL (chemotherapy treatment group) and 12 eligible children with no malignancy (control group) were enrolled and completed the study period. All 22 patients achieved the sustained virologic response with no adverse events leading to interruption or permanent discontinuation of the study drug. Compared with the control group, the ALL group patients had similar SOF, GS-331007, and LDV exposure. Compared with adults, the AUCτ of GS-331007 was lower and the AUCτ and Cmax,ss of SOF and the Cmax,ss of LDV were modestly higher in the ALL group (acceptance limit, 50%-200%). However, the observed efficacy and favorable safety profile made these changes not clinically significant.

IMPLICATIONS

Weight-based dosing of LDV/SOF (45/200 mg) is highly effective and safe among genotype 4 HCV-infected children weighing 17 to <35 kg and diagnosed with ALL undergoing maintenance chemotherapy. The similarity in the drug exposure, efficacy, and safety clinical end points between patients with and without hematological malignancy support their therapeutic equivalence. Further studies with a larger sample size may be required to confirm the safety of LDV/SOF in patients with ALL and to recommend appropriate dosing in children with hematological malignancies, if needed.

CLINICALTRIALS

gov identifier: NCT03903185.

Spectroscopic study to verify the anti-hepatitis C virus (HCV) treatment through a delivery system of the sofosbuvir drug on chitosan and pycnogenol nanoparticles surface

The target of the current study is to create a novel hybrid nanocomposite (Cs@Pyc.SOF) by combining the anti-hepatitis C virus (HCV) drug sofosbuvir with the nano antioxidant pycnogenol (Pyc) and nano biomolecules like chitosan nanoparticles (Cs NPs). The characterization procedure works to verify the creation of nanocomposite (NCP) using several different techniques. UV-Vis spectroscopy is used to measure SOF loading efficiency. The various concentrations of the SOF drug were used to determine the binding constant rate Kb, which was found to be 7.35 ± 0.95 min-1 with an 83% loading efficiency. At pH 7.4, the release rate was 80.6% after two hours and 92% after 48 h, whereas at pH 6.8, it was 29% after two hours and 94% after 48 h. After 2 and 48 h, the release rate in water was 38% and 77%, respectively. . The SRB technique for fast screening is used for the cytotoxicity test, where the investigated composites show a safety status and high viability against the examined cell line. The cytotoxicity assay of the SOF hybrid materials has been identified with cell lines like mouse normal liver cells (BNL). So, Cs@Pyc.SOF was recommended as a substitute medication for the therapy of HCV, but the results need clinical studies.

Identification and characterization of Sofosbuvir-resistant mutations of hepatitis C virus genotype 3a replicon

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide. Among its 8 genotypes (GT), GT3 has a relatively lower sustained virological response to highly effective direct-acting antiviral agents (DAA). Sofosbuvir (SOF), an anti-NS5B polymerase inhibitor, is a core component of many anti-HCV DAA cocktail regimens, and its resistant mutations are rare in clinics because these mutations usually severely impair the NS5B polymerase activity, including a mutation S282T in NS5B, the most frequently reported SOF-resistant mutation. In this study, we selected SOF-resistant variants of a previously developed GT3 subgenomic replicon (PR87A7). Two mutations were identified in the viral genome of SOF-resistant PR87A7 variants, Q606R in nontargeted NS3 and S282T in targeted N5SB. We demonstrated that Q606R could rescue the replication defect of S282T in PR87A7, and the resulting double mutant confers the SOF resistance. Finally, we showed that NS3-606R could not compensate for the replication defect of S282T in other GTs. In conclusion, we identified a novel GT3-specific combination of two mutations that confers SOF resistance. Our result calls for attention to potential mutations that may arise in nontargeted viral proteins during the SOF-based DAA treatment of chronic HCV.

Posttreatment liver function, but not baseline liver function stratifies patient survival after direct-acting antiviral treatment in decompensated cirrhosis with hepatitis C virus

BACKGROUND

The prognosis of cirrhosis is clearly stratified by liver function. Although direct-acting antiviral (DAA) has recently been used to eliminate hepatitis C virus (HCV), it is not clear whether liver function stratifies the prognosis of decompensated cirrhotic patients treated with DAA.

METHODS

A total of 206 HCV-associated decompensated cirrhotic patients who started DAA from February 2019 to December 2021 at 31 Japanese hospitals were prospectively registered.

RESULTS

The median age was 68, and the proportions of patients with Child-Pugh class A (CP-A), CP-B and CP-C were 10% (20/206), 76% (156/206) and 15% (30/206), respectively. Twenty-six patients died, and two patients underwent liver transplantation (LT); the 2- and 3-year LT-free survival rates were 90.0% and 83.2%, respectively. We examined factors associated with LT-free survival using 2 models including either CP class (Model 1) or MELD score (Model 2). In multivariate Cox proportional hazard analysis, CP class at 12 weeks after the end of treatment (EOT) in Model 1 and MELD score at 12 weeks after the EOT in Model 2 were significant factors, while baseline CP class or MELD score was not. Two-year LT-free survival rates were 100%, 91.6% and 60.4% for patients with CP-A, CP-B and CP-C at 12 weeks after the EOT and 95.2% and 69.6% for patients with MELD < 15 and MELD ≥ 15 at 12 weeks after the EOT, respectively.

CONCLUSIONS

The prognosis of decompensated cirrhotic patients receiving DAA was stratified by liver function at 12 weeks after the EOT, not by baseline liver function.

Direct-Acting Antiviral Drug Modulates the Mitochondrial Biogenesis in Different Tissues of Young Female Rats

(1) Background: Hepatitis C virus (HCV) infection is endemic in Egypt, with the highest prevalence rate worldwide. Sofosbuvir (SOF) is a nucleos(t)ide analog that specifically inhibits HCV replication. This study aimed to explore the possible effects of the therapeutic dose of SOF on the mitochondrial biogenesis and functions of the liver, muscle, and ovarian tissues of young normal female rats. (2) Methods: This study was conducted on 20 female Wistar rats, classified into two groups, the control group and the exposed group; the latter was orally supplemented with 4 mg/kg/day of SOF for 3 months. (3) Results: The exposure to SOF impairs mitochondrial biogenesis via mitochondrial DNA copy number decline and suppressed mitochondrial biogenesis-regulated parameters at mRNA and protein levels. Also, SOF suppresses the DNA polymerase γ (POLG) expression, citrate synthase activity, and mitochondrial NADH dehydrogenase subunit-5 (ND5) content, which impairs mitochondrial functions. SOF increased lipid peroxidation and oxidative DNA damage markers and decreased tissue expression of nuclear factor erythroid 2-related factor 2 (Nfe2l2). (4) Conclusions: The present findings demonstrate the adverse effects of SOF on mitochondrial biogenesis and function in different tissues of young female rats, which mostly appeared in ovarian tissues.

An insight into the hepatoprotective role of Velpatasvir and Sofosbuvir per se and in combination against carbon tetrachloride-induced hepatic fibrosis in rats

Hepatitis C is a global health issue. Hepatitis C Virus (HCV) induces fibrosis by redox reactions, which involve the deposition of collagen in extracellular matrix (ECM). This study aimed to examine the antifibrotic effect of direct-acting antivirals; Sofosbuvir and Velpatasvir, per se and in combination against carbon tetrachloride (CCl4)-induced fibrosis in rats. Carbon tetrachloride (intraperitoneal; 0.5 ml/kg) twice weekly for six weeks was used to induce hepatic fibrosis in rats. After two weeks of CCl4, oral administration of Sofosbuvir (20 mg/kg/d) and Velpatasvir (10 mg/kg/d) was administered to rats for the last four weeks. Liver function tests (LFTs), renal function tests (RFTs), oxidative stress markers, and the levels of TNF-a, NF-κB, and IL-6 were measured through ELISA and western blotting at the end of the study. CCl4 significantly ameliorated the values of RFTs, LFTs and lipid profiles in the diseased group, which were normalized by the SOF and VEL both alone and in combination. These drugs produced potent antioxidant effects by significantly increasing antioxidant enzymes. From the histopathology of hepatic tissues of rats treated with drugs, the antifibrotic effect was further manifested, which showed suppression of hepatic stellate cells (HSCs) in treated rats, as compared to the disease control group. The antifibrotic effect was further demonstrated by significantly decreasing the levels of TNF-a, NF-κB and IL-6 in serum and hepatic tissues of treated rats as compared to the disease control group. Sofosbuvir and Velpatasvir alone and in combination showed marked inhibition of fibrosis in the CCl4-induced non-HCV rat model, which was mediated by decreased levels of TNF-a/NF-κB and the IL-6 signaling pathway. Thus, it can be concluded that Sofosbuvir and Velpatasvir might have an antifibrotic effect that appears to be independent of their antiviral activity.

Effect of Sofosbuvir on rats' ovaries and the possible protective role of vitamin E: biochemical and immunohistochemical study

Hepatitis C virus (HCV) infection is a major health problem worldwide and its eradication is mandatory. Direct acting HCV polymerase inhibitors, such as Sofosbuvir (SOF), is an effective regimen. However, it has some side effects like mutagenesis, carcinogenesis, and the impairment of testicular function. It is important to evaluate the safety of SOF on the ovary, as there are no studies yet. Increasing the production of Reactive Oxygen Species (ROS), causes oxidative stress, which affects ovulation process, female reproduction, and fertility. Accumulation of SOF in the cells was demonstrated to promote ROS generation. Vitamin E (Vit E) is an antioxidant agent that has an essential role in the female reproductive system, its deficiency can cause infertility. We explored the effect of SOF treatment alone and co-treated with Vit E on ovarian ROS level and ovarian morphology experimentally using biochemical and immunohistochemical studies. Significant changes in oxidative stress markers; nitric oxide and malondialdehyde lipid peroxidation, antioxidant enzymes; catalase, super oxide dismutase, and reduced glutathione, proliferating markers; proliferation cell nuclear antigen and Ki-67 antigen and caspase 3 apoptotic marker were demonstrated. It was shown that where SOF induced oxidative stress, it also aggravated ovarian dysfunction. The essential role of Vit E as an antioxidant agent in protecting the ovarian tissue from the effect of oxidative stress markers and preserving its function was also displayed. This could be guidance to add Vit E supplements to SOF regimens to limit its injurious effect on ovarian function.

Evolution of estimated glomerular filtration rate in HIV/HCV-coinfected patients who received direct-acting antivirals: A multicenter retrospective study

BACKGROUND

The short-term impact of sofosbuvir (SOF)-based direct-acting antivirals (DAAs) combined with antiretroviral therapy (ART) on renal function in patients with HIV/HCV-coinfection remains controversial.

METHODS

This multicenter, retrospective study aimed to sequentially record the estimated glomerular filtration rate (eGFR) at baseline, end of therapy (EOT), 12 weeks off-treatment (SVR12), and at time points after SVR12 (post-SVR12) and to identify the factors associated with an eGFR decline to <60 ml/min/1.73 m2 in HIV/HCV-coinfected patients receiving DAAs. The evolution of mean eGFRs between different ART and DAAs combinations among patients of different HIV transmission routes were compared using a generalized linear mixed effects model. The periods between baseline and EOT, between EOT and post-SVR12, and between baseline and post-SVR12 were defined as the on-treatment, post-treatment, and all-course periods, respectively. Acute kidney disease (AKD) was defined as a decline of eGFR to <60 ml/min/1.73 m2.

RESULT

A total of 445 patients with baseline eGFRs >60 ml/min/1.73 m2 were included. We found that eGFRs declined during the on-treatment period in the tenofovir-containing ART and SOF-based DAA groups. There were no differences in the slope coefficient during the on-treatment and post-treatment periods among all risk groups except for people who inject drug. Increasing age and plasma HIV RNA >20 copies/ml before DAA treatment were factors independently associated with AKD during the on-treatment period while increasing age was independently associated with AKD during the all-course period.

CONCLUSION

Only increasing age was an independent factor associated with AKD among HIV/HCV-coinfected patients during and after DAA treatments.

Differential activity of nucleotide analogs against tick-borne encephalitis and yellow fever viruses in human cell lines

With no approved antiviral therapies, the continuous emergence and re-emergence of tick-borne encephalitis virus (TBEV) and yellow fever virus (YFV) is a rising concern. We performed head-to-head comparisons of the antiviral activity of available nucleos(t)ide analogs (nucs) using relevant human cell lines. Eight existing nucs inhibited TBEV and/or YFV with differential activity between cell lines and viruses. Remdesivir, uprifosbuvir and sofosbuvir were the most potent drugs against TBEV and YFV in liver cells, but they had reduced activity in neural cells, whereas galidesivir retained uniform activity across cell lines and viruses. Ribavirin, valopicitabine, molnupiravir and GS-6620 exhibited only moderate antiviral activity. We found antiviral activity for drugs previously reported as inactive, demonstrating the importance of using human cell lines and comparative experimental assays when screening the activity of nucs. The relatively high antiviral activity of remdesivir, sofosbuvir and uprifosbuvir against TBEV and YFV merits further investigation in clinical studies.

Mathematical processing of absorption as green smart spectrophotometric methods for concurrent assay of hepatitis C antiviral drugs, Sofosbuvir and Simeprevir: application to combined pharmaceutical dosage forms and evaluation of the method greenness

The present work was developed to create three rapid, simple, eco-friendly, cheap spectrophotometric methods for concurrent assay of Sofosbuvir (SOF) and Simeprevir (SMV) in their pure, laboratory prepared mixture and pharmaceutical dosage form with high degree of accuracy and precision. Three methods were developed including iso-absorptive point, ratio subtraction and dual wavelength. The linear range of the proposed methods was 3.0-50.0 and 2.0-50.0 µg mL^-1 for SMV and SOF, respectively. The proposed methods were validated according to ICH guidelines in terms of linearity, accuracy, precision, limit of detection and limit of quantitation. The proposed approach is highly simple and the procedure is environmentally green making it suitable for the drug analysis in routine works.

The pre-conception maternal exposure to Sofosbuvir affects the mitochondrial biogenesis in prenatal fetal tissues: Experimental study on rats

BACKGROUND

 Hepatitis C virus (HCV) infection is a global public health problem and Egypt has the highest HCV prevalence worldwide. Hence, global efforts target to eliminate HCV by 2030. Sofosbuvir is a nucleotide analogue inhibitor of HCV polymerase essential for viral replication. Animal studies prove that Sofosbuvir metabolites cross the placenta and are excreted in the milk of nursing animals. We aimed to investigate the possible effects of preconception maternal exposure to Sofosbuvir on mitochondrial biogenesis in prenatal fetal liver, skeletal muscle, and placental tissues.

METHODS

 The study was conducted on 20 female albino rats divided into a control group receiving a placebo and an exposed group receiving 4 mg/kg orally/day for 3 months of Sofosbuvir. At the end of the treatment period, pregnancy was induced in both groups by mating with healthy male rats overnight. At gestational day 17, all pregnant female rats were sacrificed. Each fetus was dissected to obtain the fetal liver, skeletal muscle, and placental tissues.

RESULTS

 The results of our study indicated that the exposure of young female rats to Sofosbuvir affects pregnancy outcomes. Fetal liver and muscle showed lower mitochondrial DNA-copy number (mtDNA-CN) by about 24% and 29% respectively, peroxisome proliferator-activated receptor-gamma coactivator-1 alpha and its downstream targets; nuclear respiratory factor-1 and mitochondrial transcription factor A. While the placental tissues showed different patterns, particularly elevated in mtDNA-CN by about 43%.

CONCLUSIONS

 The study provides preliminary evidence of the detrimental effects of Sofosbuvir on the pregnancy outcomes of the exposed females and may impair the placental and fetal organs' development. These effects may be mediated through modulating mitochondrial homeostasis and functions.

Construction of quaternary stereocenters at carbon 2' of nucleosides

The non-natural nucleosides with a quaternary stereogenic center at C2' are crucial to drug discovery. They have become a cornerstone for the treatment of cancer and various viral infections as exemplified by gemcitabine and sofosbuvir. Major research effort has been expended to gain synthetic access to these nucleoside analogues with a significant steric bulk at C2' in the furanoside ring. The 2'-ketonucleosides and 2'-deoxy-2'-methylenenucleosides emerged as key intermediates in these synthetic strategies. For example, α-face addition of methyl lithium to the 2'-ketonucleosides followed by fluorination of resulting tertiary arabino alcohol with DAST provided 2'-fluoro-2'-C-methyluridine - a core nucleoside component of sofosbuvir. The α-face addition of HCN or HN₃ to the 2'-deoxy-2'-methylene nucleosides gave access to the synthetically versatile 2'-cyano-2'-C-methyl and 2'-azido-2'-C-methyl nucleosides. Likewise, the addition of diazomethane to the 2'-exomethylene group gave access to the 2'-spirocyclopropyl analogue. This review primarily discusses synthetic strategies which employs natural nucleosides as substrates but selected approaches involving coupling of the preelaborated sugar precursors with nucleobases are also examined.

Antivirals for adult patients hospitalised with SARS-CoV-2 infection: a randomised, phase II/III, multicentre, placebo-controlled, adaptive study, with multiple arms and stages. COALITION COVID-19 BRAZIL IX - REVOLUTIOn trial

Background

Repurposed drugs for treatment of new onset disease may be an effective therapeutic shortcut. We aimed to evaluate the efficacy of repurposed antivirals compared to placebo in lowering SARS-CoV2 viral load of COVID-19 patients.

Methods

REVOLUTIOn is a randomised, parallel, blinded, multistage, superiority and placebo controlled randomised trial conducted in 35 centres in Brazil. We include patients aged 18 years or older admitted to hospital with laboratory-confirmed SARS-CoV-2 infection, symptoms onset 9 days or less and SpO₂ 94% or lower at room air were eligible. All participants were randomly allocated to receive either atazanavir, daclatasvir or sofosbuvir/daclatasvir or placebo for 10 days. The primary outcome was the decay rate (slope) of the SARS-CoV-2 viral load logarithm assessed in the modified intention to-treat population. This trial was registered with ClinicalTrials.gov, number NCT04468087.

Findings

Between February 09, 2021, and August 04, 2021, 255 participants were enrolled and randomly assigned to atazanavir (n = 64), daclatasvir (n = 66), sofosbuvir/daclatasvir (n = 67) or placebo (n = 58). Compared to placebo group, the change from baseline to day 10 in log viral load was not significantly different for any of the treatment groups (0.05 [95% CI, -0.03 to 0.12], -0.02 [95% CI, -0.09 to 0.06], and -0.03 [95% CI, -0.11 to 0.04] for atazanavir, daclatasvir and sofosbuvir/daclatasvir groups respectively). There was no significant difference in the occurrence of serious adverse events between treatment groups.

Interpretation

No significant reduction in viral load was observed from the use of atazanavir, daclatasvir or sofosbuvir/daclatasvir compared to placebo in hospitalised COVID-19 patients who need oxygen support with symptoms onset 9 days or less.

Funding

Ministério da Ciência, Tecnologia e Inovação (MCTI) - Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ); Cia Latino-Americana de Medicamentos (Clamed); Cia Industrial H. Carlos Schneider (Ciser); Hospital Research Foundation Incorporation, Australia, HCor São Paulo; Blanver Farmoquímica; Instituto de Tecnologia em Fármacos (Farmanguinhos) da Fundação Oswaldo Cruz (Fiocruz); Coordenação Geral de Planejamento Estratégico (Cogeplan)/Fiocruz; and Fundação de apoio a Fiocruz (Fiotec, VPGDI-054-FIO-20-2-13).

Selective profiling of liver-related specific proteins based on sofosbuvir-modified magnetic separation material

It has great significance in profiling specific proteins throughout for better understanding of complex pathological processes and in-depth pharmacological studies. In this work, an efficient protein profiling strategy was developed based on the specific protein-drug interaction. Sofosbuvir (SOF), as a first-line drug for the treatment of hepatitis C, was modified onto the surface of nanoparticles through stable chemical bonds to fabricate a novel magnetic separation material denoted as Fe₃O₄@SiO₂@PAA@SOF. With sequence coverage as the screening parameter, nine proteins were profiled from fetal bovine serum (FBS) of which eight were liver related. Similarly, the strategy was applied to hepatocellular carcinoma (HCC) patient serum. Eight proteins were profiled and all of them were liver related, demonstrating the superb specificity and selectivity of this strategy for profiling liver-related proteins by virtue of protein-SOF interaction. When serum proteins from HCC patients were compared to those from healthy people, one unique differential protein (D3DQX7) was profiled, which was liver related and was a potential target for ameliorating liver diseases. For further research, this material design concept and protein profiling strategy can be extended to employ other drugs for corresponding studies. Sofosbuvir, as a therapeutic drug for liver diseases, was modified onto the surface of magnetic nanoparticles to fabricate the specific selective separation material (Fe₃O₄@SiO₂@PAA@SOF). Based on protein-SOF interaction, the material was applied to adsorb specific proteins from different serum samples. After MS analysis, specific proteins, most of which were liver related, were successfully profiled from FBS and HCC patient serum, fully demonstrating the superb specificity and selectivity of this protein profiling strategy.

Glecaprevir/pibrentasvir + sofosbuvir for post-liver transplant recurrent hepatitis C virus treatment

Glecaprevir/pibrentasvir in combination with sofosbuvir may serve as a safe and effective option for treatment of recurrent hepatitis C virus post-liver transplant in patients who previously failed direct-acting antivirals.

Short-term hepatocyte function and portal hypertension outcomes of sofosbuvir/velpatasvir for decompensated hepatitis C-related cirrhosis

BACKGROUND

It is unclear whether hepatocyte function and/or portal hypertension improves if a sustained virologic response (SVR) is achieved with direct-acting antivirals in patients with decompensated hepatitis C-related cirrhosis.

METHODS

We examined the safety and efficacy of a 12-week course of sofosbuvir/velpatasvir (SOF/VEL) in 20 patients with decompensated hepatitis C-related cirrhosis. We also investigated changes in the hepatocyte receptor index (LHL15) and blood clearance index (HH15) by Tc-99 m-galactosyl human serum albumin scintigraphy, liver stiffness measurement (LSM) by transient elastography, and hepatic venous pressure gradient (HVPG) in patients who achieved an SVR at 24 weeks after treatment (SVR24).

RESULTS

One patient discontinued treatment because of rectal variceal hemorrhage, and 19 patients completed treatment. SVR24 was achieved in 17 patients (89%). Median LHL15 increased from 0.72 pre-treatment to 0.82 after SVR24 (p = 0.012), and median HH15 decreased from 0.82 pre-treatment to 0.76 after SVR24 (p = 0.010). The percentage of patients with LSM ≥ 20 kPa was 90% before treatment and remained at 90% after SVR24. However, the percentage with severe portal hypertension (defined as HVPG ≥ 12 mmHg) decreased from 92% pre-treatment to 58% after SVR24 (p = 0.046). Patients with a decreased HVPG from pre-treatment to after SVR24 had a smaller pre-treatment spleen volume than those with an increased HVPG (median, 252 vs. 537 mL, p = 0.028).

CONCLUSION

Achieving SVR24 with SOF/VEL treatment in patients with decompensated hepatitis C-related cirrhosis can be expected to improve hepatocyte function and portal hypertension on short-term follow-up.

Sofosbuvir/velpatasvir/voxilaprevir for patients with chronic hepatitis C virus infection previously treated with NS5A direct-acting antivirals: a real-world multicenter cohort in Taiwan

BACKGROUND

Real-world data are scarce about the effectiveness and safety of sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) for retreating East Asian patients with hepatitis C virus (HCV) infection who previously received NS5A direct-acting antivirals (DAAs). We conducted a multicenter study to assess the performance of SOF/VEL/VOX in patients who were not responsive to prior NS5A inhibitors in Taiwan.

METHODS

Between September 2021 and May 2022, 107 patients who failed NS5A inhibitor-containing DAAs with SOF/VEL/VOX salvage therapy for 12 weeks were included at 16 academic centers. The sustained virologic response at off-treatment week 12 (SVR₁₂) was assessed in the evaluable (EP) and per-protocol (PP) populations. The safety profiles were also reported.

RESULTS

All patients completed 12 weeks of treatment and achieved an end-of-treatment virologic response. The SVR₁₂ rates were 97.2% (95% confidence interval (CI) 92.1-99.0%) and 100% (95% CI 96.4-100%) in EP and PP populations. Three (2.8%) patients were lost to off-treatment follow-up and did not meet SVR₁₂ in the EP population. No baseline factors predicted SVR₁₂. Two (1.9%) not-fatal serious adverse events (AE) occurred but were unrelated to SOF/VEL/VOX. Sixteen (15.0%) had grade 2 total bilirubin elevation, and three (2.8%) had grade 2 alanine transaminase (ALT) elevation. Thirteen (81.3%) of the 16 patients with grade 2 total bilirubin elevation had unconjugated hyperbilirubinemia. The estimated glomerular filtration rates (eGFR) were comparable between baseline and SVR₁₂, regardless of baseline renal reserve.

CONCLUSIONS

SOF/VEL/VOX is highly efficacious and well-tolerated for East Asian HCV patients previously treated with NS5A inhibitor-containing DAAs.

CLINICAL TRIALS REGISTRATION

The study was not a drug trial. There was no need for clinical trial registration.

Sofosbuvir and its tri-phosphate metabolite inhibit the RNA-dependent RNA polymerase activity of non-structural protein 5 from the Kyasanur forest disease virus

Kyasanur forest disease is a neglected zoonotic disease caused by a single-stranded RNA-based flavivirus, the incidence of which was first recorded in 1957 in the Southern part of India. Kyasanur forest disease virus is transmitted to monkeys and humans through the infected tick bite of Haemophysalis spinigera. Kyasanur forest disease is a febrile illness, which in severe cases, results in neurological complications leading to mortality. The current treatment regimens are symptomatic and supportive, and no targeted therapies are available for this disease. In this study, we evaluated the ability of FDA-approved drugs sofosbuvir (and its active metabolite) and Dasabuvir to inhibit the RNA-dependent RNA polymerase activity of NS5 protein from the Kyasanur forest disease virus. NS5 protein containing the N-terminal methyl transferase domain and C-terminal RNA-dependent RNA polymerase domain was expressed in Escherichia coli, and RNA-dependent RNA polymerase activity was demonstrated with the purified protein. The RNA-dependent RNA polymerase assay conditions were optimized, followed by the determination of apparent K_m,ATP to validate the enzyme preparation. Half maximal-inhibitory concentrations against RNA-dependent RNA polymerase activity were determined for Sofosbuvir and its active metabolite. Dasabuvir did not show detectable inhibition with the tested conditions. This is the first demonstration of the inhibition of RNA-dependent RNA polymerase activity of NS5 protein from the Kyasanur forest disease virus with small molecule inhibitors. These initial findings can potentially facilitate the discovery and development of targeted therapies for treating Kyasanur forest disease.

Covalent CES2 Inhibitors Protect against Reduced Formation of Intestinal Organoids by the Anticancer Drug Irinotecan

BACKGROUND

Irinotecan is widely used to treat various types of solid and metastatic cancer. It is an ester prodrug and its hydrolytic metabolite (SN-38) exerts potent anticancer activity. Irinotecan is hydrolyzed primarily by carboxylesterase-2 (CES2), a hydrolase abundantly present in the intestine such as the duodenum. We have identified several potent and covalent CES2 inhibi¬tors such as remdesivir and sofosbuvir. Remdesivir is the first small molecule drug approved for COVID-19, whereas sofosbuvir is a paradigm-shift medicine for hepatitis C viral infection. Irinotecan is generally well-tolerated but associated with severe/life-threatening diarrhea due to intestinal accu¬¬mula¬tion of SN-38.

OBJECTIVE

This study was to test the hypothesis that remdesivir and sofosbuvir protect against irinotecan-induced epithelial injury associated with gastrointestinal toxicity.

METHODS

To test this hypothesis, formation of organoids derived from mouse duodenal crypts, a robust cellular model for intestinal regeneration, was induced in the presence or absence of irinotecan +/- pretreatment with a CES2 drug inhibitor.

RESULTS

Irinotecan profoundly inhibited the formation of intestinal organoids and the magnitude of the inhibition was greater with female crypts than their male counterparts. Consistently, crypts from female mice had significantly higher hydrolytic activity toward irinotecan. Critically, remdesivir and sofosbuvir both reduced irinotecan hydrolysis and reversed irinotecan-reduced formation of organoids. Human duodenal samples robustly hydrolyzed irinotecan, stable CES2 transfection induced cytotoxicity and the cytotoxicity was reduced by CES2 drug inhibitor.

CONCLUSION

These findings establish a therapeutic rationale to reduce irinotecan-gastrointestinal injury and serve as a cellular foundation to develop oral formulations of irinotecan with high safety.

Effectiveness and safety of generic and brand direct acting antivirals for treatment of chronic hepatitis C

BACKGROUND

Direct acting antivirals (DAAs) are a very effective treatment for hepatitis C virus (HCV). However, brand DAAs are expensive. The licensing of cheaper generic DAAs may address this issue, but there is a lack of clinical studies comparing the efficacy of generic vs brand DAA formulations.

AIM

To compare the efficacy and safety of generic against brand DAAs for chronic hepatitis C treatment in Bahrain.

METHODS

This was a retrospective observational study involving 289 patients with chronic HCV infection during 2016 to 2018. There were 149 patients who were treated with brand DAAs, while 140 patients were treated with generic DAAs. Commonly used DAAs were Ombitasvir/Paritaprevir/Ritonavir ± Dasabuvir ± Ribavirin, and Sofosbuvir/Daclatasvir ± Ribavirin. SVR at 12 wk post treatment was the main outcome variable.

RESULTS

Overall, 87 patients (30.1%) had cirrhosis and 68.2% had genotype 1 HCV infection. At 12 wk post treatment, SVR was achieved by 271 (93.8%) of the patients. In patients who were treated with generic medications, 134 (95.7%) achieved SVR at 12 wk post treatment, compared to 137 (91.9%) among those treated with brand medications (P = 0.19). Having cirrhosis [odds ratio (OR): 9.41, 95% confidence interval (CI): 2.47–35.84] and having HCV genotype 3 (OR: 3.56, 95%CI: 1.03–12.38) were significant independent predictors of not achieving SVR. Alanine transaminase, gamma-glutamyl transpeptidase, and total bilirubin levels decreased significantly following therapy with both generic and brand DAAs.

CONCLUSION

Generic and brand DAAs demonstrate comparable effectiveness in the treatment of chronic hepatitis C patients. Both are safe and equally effective in improving biochemical markers of hepatic inflammation.

Circulating microRNAs as predictors of response to sofosbuvir + daclatasvir + ribavirin in in HCV genotype-4 Egyptian patients

BACKGROUND

MicroRNAs (miRNAs) play an important role in various diseases, including HCV infection, the aim of the current study was to evaluate the potential use of serum miRNAs as biomarkers for diagnosis, prognosis, and prediction of responses to direct acting antivirals (sofosbuvir + daclatasvir + ribavirin) in HCV-4 patients.

METHODS

The serum expression profiles of four liver-associated miRNAs (miRNA-122, 155, 196 and 29) were assessed in 160 HCV-4 patients and 50 healthy controls using real-time PCR prior to therapy.

RESULTS

miR-122 and miR-155 showed upregulation in HCV-4 patients compared to healthy controls while miR-196 and miR-29 showed downregulation in HCV-4 patients. ROC curve analyses revealed that the four-studied miRNAs could be valuable biomarkers for predicting response to DAAs with AUC 0.973 for miR-122, 0.878 for miR-155, 0.808 for miR-29 and 0.874 for miR-196 respectively. Univariate logistic regression analysis revealed that miR-196 level is positive predictor for SVR, whereas miR-122,155 levels are negative predictors of response. Multivariate logistic regression analysis revealed that miR-196 is the most significant in predicting response to treatment (p value = 0.011).

CONCLUSION

To the best of our knowledge, the current study provided the first clinical evidence of the potential use of circulating miRNAs (miR; 122, 155, 196 and 29) as biomarkers of CHC in HCV-4 patients receiving the new DAA regimen (SOF/DAV + RIB), which is a strong motivator for further studies.

Real-life experience of ledipasvir and sofosbuvir for HCV infected Korean patients: a multicenter cohort study

BACKGROUND/AIMS

To evaluate the efficacy and safety of ledipasvir/sofosbuvir (LDV/SOF) therapy in hepatitis C virus (HCV)-infected Korean patients in a real clinical setting.

METHODS

A total of 273 patients who received LDV/SOF therapy between May 2016 and February 2021 were consecutively enrolled and analyzed. A per-protocol analysis was performed to evaluate the virologic response.

RESULTS

Seventy-five percent were infected with genotype 1, and 25% were infected with genotype 2. A hundred eightyone (66.3%) patients had chronic hepatitis, 74 (27.1%) had compensated cirrhosis, eight (2.9%) had decompensated cirrhosis, and 10 (3.7%) had undergone liver transplantation. Undetectable HCV RNA at week 4 was achieved in 90.2% (231/256) of patients, 99.2% (250/252) achieved the end of treatment response, and 98.1% (202/206) achieved sustained virologic response at 12 weeks post-treatment (SVR12). According to liver function, the SVR12 rates were 99.3% (135/136) in chronic hepatitis, 96.4% (53/55) in compensated cirrhosis, and 100% (6/6) in decompensated cirrhosis. The SVR12 rates according to the genotype were 98.2% (167/170) for genotype 1 and 97.2% (35/36) for genotype 2. An 8-week LDV/SOF treatment in treatment-naïve chronic hepatitis patients with HCV RNA &lt; 6,000,000 IU/mL at baseline resulted in 100% (23/23) SVR12 rates. Overall, LDV/SOF was tolerated well, with a 0.7% (2/273) discontinuation rate due to adverse events that were unrelated to LDV/SOF.

CONCLUSION

LDV/SOF is effective and safe for treating HCV-infected Korean patients with high SVR12 rates.

RP-HPLC Method Development, Validation, and Drug Repurposing of Sofosbuvir Pharmaceutical Dosage Form: A Multidimensional Study

A smooth, exceptionally sensitive, correct, and extra reproducible RP-HPLC technique was developed and demonstrated to estimate Sofosbuvir (SOF) in pharmaceutical dosage formulations. This process was carried out by Agilent High-Pressure Liquid Chromatograph 1260 with GI311C Quat. Pump, Phenomenex Luna C-18 (150 mm × 4.6 mm × 5 μm) (USA), and Photodiode Array Detector (PDA) G1315D. The cell section, including acetonitrile and methanol with 80:20 v/v and solution (B) 0.1% phosphoric acid (40:60), was used for the study. However, 10 μL of the sample was injected with a drift flow of 1 mL/min. The separation occurred at a column temperature of 30 °C, and the eluents used PDA set at 260 nm. The retention time of SOF was 5 min. The calibration curve was modified linearly within the range of 0.05-0.15 mg/mL with a correlation coefficient of 0.99 and genuine linear dating among top vicinity and consciousness in the calibration curve. The detection and quantification restrictions were 0.001 and 0.003 mg/mL, respectively. SOF recovery from pharmaceutical components ranged from 98% to 99%. The percentage assay of SOF was 99%. Analytical validation parameters, such as specificity, linearity, precision, accuracy, and selectivity, were studied, and the percentage relative standard deviation (%RSD) was less than 2%. All other key parameters were observed within the desired thresholds. Hence, the proposed RP-HPLC technique was proven effective for developing SOF in bulk and pharmaceutical pill dosage forms. SOF was found to interact with SARS-COV-2 nsp12, and molecular docking results revealed its high affinity and firm binding within the active site groove of nsp12. The key interacting residues include; LYS-72, GLN-75, MET-80 ALA-99, ASN-99, TRP-100, TYR-101 with ASN-99 and TRP-100 forming hydrogen bonds. Molecular Dynamics simulation of SOF and nsp12 complex elucidated that the system was stable throughout 20ns. Therefore, this drug repurposing strategy for SOF can be used for treating COVID-19 infections by performing animal experiments and accurate clinical trials in the future.

Dual versus triple therapy in treatment of hepatitis C virus (HCV)

BACKGROUND

The goal of HCV treatment is eradication of the virus to prevent complications associated with the disease and decrease all-cause mortality. This work compared sustained viral response (SVR) 12 weeks after end of treatment of chronic HCV patients with different treatment regimens, namely 4 regimens. Two hundred treatment naive chronic HCV patients were selected and divided into 4 equal groups as follows: group A received pegylated interferon (peg IFN) and ribavirin (RBV); group B received peg IFN, RBV, and sofosbuvir (SOF); group C received RBV and SOF; group D received SOF, daclatasvir (DCV), and RBV.

RESULTS

The sustained viral response after 12 months of treatment is 57.23%, 72.09%, 64.40%, and 96.42% of patients in groups A, B, C, and D, respectively. Hence, group D regimen showed the best results.

CONCLUSION

SOF and DCV and RBV have the highest SVR12 and least side effects compared to other treatment regimens. Although group D patients initially had poor pretreatment investigations relative to other groups, they proved to have the highest tolerability to this regimen. Such findings hold promising line of treatment and better prognosis even for chronic HCV patients with poor liver condition.

Effects of aged garlic and ginkgo biloba extracts on the pharmacokinetics of sofosbuvir in rats

Sofosbuvir is a direct acting antiviral (DAA) approved for the treatment of hepatitis C virus (HCV). Sofosbuvir is a substrate of P-glycoprotein (P-gp). For this reason, inhibitors, or inducers of intestinal P-gp may alter plasma concentration of sofosbuvir and increase or decrease its efficacy causing a significant change in its pharmacokinetic parameters. The purpose of study was to evaluate the pharmacokinetic interaction between either aged garlic or ginkgo biloba extracts with sofosbuvir through targeting P-gp as well as the possible toxicities in rats. Rats were divided into four groups and treated for 14 days with saline, verapamil (15 mg/kg, PO), aged garlic extract (120 mg/kg, PO) or ginkgo biloba extract (25 mg/kg, PO) followed by a single oral dose of sofosbuvir (40 mg/kg). Validated LC-MS/MS was used to determine sofosbuvir and its metabolite GS-331007 in rat plasma. Aged garlic extract caused a significant decrease of sofosbuvir AUC_(0-t) by 36% while ginkgo biloba extract caused a significant increase of sofosbuvir AUC_(0-t) by 11%. Ginkgo biloba extract exhibited significant increase of sofosbuvir t_1/2 by 60%, while aged garlic extract significantly increased sofosbuvir clearance by 63%. The pharmacokinetic parameters of GS-331007 were not affected. The inhibitory action of ginkgo biloba on P-gp and the subsequent increase in sofosbuvir plasma concentration did not show a significant risk of renal or hepatic toxicity. Conversely, although aged garlic extracts increased intestinal P-gp expression, they did not alter C_max and T_max of sofosbuvir and did not induce significant hepatic or renal toxicities. This article is protected by copyright. All rights reserved.

Ledipasvir/sofosbuvir for HCV genotype 1, 2, 4-6 infection: Real-world evidence from a nationwide registry in Taiwan

BACKGROUND/PURPOSE

The Taiwan Association for the Study of the Liver (TASL) HCV Registry (TACR) is a nationwide registry of chronic hepatitis C patients in Taiwan. This study evaluated antiviral effectiveness of ledipasvir (LDV)/sofosbuvir (SOF) in patients in the TACR.

METHODS

Patients enrolled in TACR from 2017-2020 treated with LDV/SOF were eligible. The primary outcome was the proportion of patients with sustained virologic response 12 weeks after end of treatment (SVR12).

RESULTS

5644 LDV/SOF ± ribavirin-treated patients were included (mean age: 61.4 years; 54.4% female). Dominant viral genotypes were GT1 (50.8%) and GT2 (39.3%). 1529 (27.1%) patients had liver cirrhosis, including 201 (3.6%) with liver decompensation; 686 (12.2%) had chronic kidney disease. SVR12 was achieved in 98.6% of the overall population and in 98.2% and 98.7% of patients with and without cirrhosis, respectively. SVR12 rates in patients with compensated cirrhosis treated with LDV/SOF without RBV were >98%, regardless of prior treatment experience. SVR12 was 98.6%, 98.4%, 100%, 100%, and 98.7% among those with GT1, GT2, GT4, GT5, and GT6 infections, respectively. Although patient numbers were relatively small, SVR12 rates of 100% were reported in patients infected with HCV GT2, GT5, and GT6 with decompensated cirrhosis and 98% in patients with severely compromised renal function. LDV/SOF adherence ≤60% (P < 0.001) was the most important factor associated with treatment failure. Incidence of adverse events was 15.8%, with fatigue being the most common.

CONCLUSION

LDV/SOF is effective and well tolerated in routine clinical practice in Taiwan. Cure rates were high across patient populations.

Pan-genotypic direct-acting antivirals for patients with hepatitis C virus infection and chronic kidney disease stage 4 or 5

Hepatitis C virus (HCV) infection is a major health problem with significant clinical and economic burdens in patients with chronic kidney disease (CKD) stage 4 or 5. Current guidelines recommend pan-genotypic direct-acting antivirals (DAAs) to be the first-line treatment of choice for HCV. This review summarizes the updated knowledge regarding the epidemiology, natural history, public health perspectives of HCV in patients with CKD stage 4 or 5, including those on maintenance dialysis, and the performance of pan-genotypic DAAs in these patients. The prevalence and incidence of HCV are much higher in patients with CKD stage 4 or 5 than in the general population. The prognosis is compromised if HCV patients are left untreated regardless of kidney transplantation (KT). Following treatment-induced HCV eradication, patient can improve the health-related outcomes by maintaining a long-term aviremic state. The sustained virologic response (SVR₁₂) rates and safety profiles of pan-genotypic DAAs against HCV are excellent irrespective of KT. No dose adjustment of pan-genotypic DAAs is required across CKD stages. Assessing drug–drug interactions (DDIs) before HCV treatment is vital to secure on-treatment safety. The use of prophylactic or preemptive pan-genotypic DAAs in HCV-negative recipients who receive HCV-positive kidneys has shown promise in shortening KT waiting time, achieving excellent on-treatment efficacy and safety, and maintaining post-KT patient and graft survival. HCV elimination is highly feasible through multifaceted interventions, including mass screening, treatment scale-up, universal precautions, and post-SVR₁₂ reinfection surveillance.

Effect of Sofosbuvir on Length of Hospital Stay in Moderate COVID-19 Cases; a Randomized Controlled Trial

INTRODUCTION

Efforts to control the COVID-19 pandemic are still on. This study aimed to evaluate the effect of sofosbuvir on length of hospital stay and complications in COVID-19 cases with moderate severity.

METHODS

This randomized clinical trial was done on moderate COVID-19 cases, who were admitted to Shohadaye Tajrish Hospital, Tehran, Iran, from 4/2021 to 9/2021. Eligible patients were randomly allocated into two groups of intervention (sofosbuvir) and control, and their outcomes were compared regarding the length of hospital stay and complications.

RESULTS

100 COVID-19 cases were randomly divided into two groups of 50 patients, as the intervention and control groups. The mean age of patients was 50.56 ± 12.23 and 57.1±14.1 years in the intervention and control groups, respectively (p = 0.02). The two groups were similar regarding distribution of gender (p = 0.15), underlying diseases (p = 0.08), the severity of COVID-19 (p = 0.80) at the time of admission, signs and symptoms (p > 0.05), and essential laboratory profile (p > 0.05). The length of hospital stay in the control and intervention groups was 7.7 ± 4.09 days and 4.7±1.6 days, respectively (p = 0.02). None of our patients needed ICU or mechanical ventilation.

CONCLUSION

Sofosbuvir may decrease the length of hospital stay of COVID-19 cases with moderate severity, without a significant effect on the rate of intensive care unit (ICU) need and mortality.

Sofosbuvir-based Therapy for Late Pregnant Women and Infant with Severe Chronic Hepatitis C: A Case Series Study

Data on sofosbuvir-based therapy for pregnant women and infant with severe chronic hepatitis C (CHC) are lacking. Two late pregnant women and one female infant with severe CHC were enrolled for treatment. Pregnant women 1 and 2 and infant 3 were 30, 33, and 1.2 years old, respectively; the gestational ages of pregnant women 1 and 2 were 31 and 26 weeks, respectively. Notably, pregnant women 1 and 2 and infant 3 had hepatitis C virus (HCV) RNA levels of 139000, 198000, and 8450000 IU/ml; alanine aminotransferase levels of 420, 781, and 220 U/L; and received sofosbuvir/ledipasvir, sofosbuvir/velpatasvir, and sofosbuvir/ledipasvir for 12 weeks, respectively. All three patients were safely cured with favorable tolerance, and two newborns were both breastfeeding and were consistently negative for the anti-HCV antibody during the one-year follow-up after birth. Additionally, two newborns and infant 3 had normal growth parameters during the follow-up year one. In conclusion, this case series study found that sofosbuvir-based therapy for pregnant women and infant with severe CHC is safe and effective. The data may fill the gap and provide evidence of the use of sofosbuvir-based therapy as a reference when similar severe CHC situations are encountered during clinical practice. This article is protected by copyright. All rights reserved.

Application of different spectrophotometric methods for quantitative analysis of direct acting antiviral drugs simeprevir and sofosbuvir

Simeprevir and sofosbuvir are direct-acting antiviral drugs approved for the treatment of chronic HCV infection. Reports demonstrate the similarities between HCV and SARS-CoV-2 in terms of structure and replication mechanism. Therefore, it is suggested that a combination of simeprevir and sofosbuvir may be considered for COVID-19 patients. To date, no spectrophotometric methods have been published for quantitative analysis of simeprevir and sofosbuvir in combination. In this work, two simple spectrophotometric methods allowed quantitative analysis of the studied drugs in the mixed form. The zero-order direct method allowed quantitative analysis of simeprevir at 333 nm, with sofosbuvir showing zero absorbance values. The dual wavelength method allowed quantitative analysis of sofosbuvir by measuring the difference in absorbance values at 259.40 and 276 nm, where the difference in absorbance values of simeprevir was zero. With the applied methods, the investigated drugs in the mixtures and tablets prepared in the laboratory were successfully analyzed quantitatively with acceptable results.

Impact of Sofosbuvir-Based Direct-Acting Antivirals on Renal Function in Chronic Hepatitis C Patients With Impaired Renal Function: A Large Cohort Study From the Nationwide HCV Registry Program (TACR)

BACKGROUND & AIMS

Sofosbuvir is approved for chronic hepatitis C (CHC) patients with severe chronic kidney disease (CKD). The impact of sofosbuvir-based therapy on renal function augmentation on a real-world nationwide basis is elusive.

METHODS

The 12,995 CHC patients treated with sofosbuvir-based (n = 6802) or non-sofosbuvir-based (n = 6193) regimens were retrieved from the Taiwan nationwide real-world HCV Registry Program. Serial estimated glomerular filtration rate (eGFR) levels were measured at baseline, end of treatment (EOT), and end of follow-up (EOF) (3 months after EOT).

RESULTS

The eGFR decreased from baseline (91.4 mL/min/1.73 m²) to EOT (88.4 mL/min/1.73 m²; P < .001) and substantially recovered at EOF (88.8 mL/min/1.73 m²) but did not return to pretreatment levels (P < .001). Notably, a significant decrease in eGFR was observed only in patients with baseline eGFR ≥90 mL/min/1.73 m² (from 112.9 to 106.4 mL/min/1.73 m²; P < .001). In contrast, eGFR increased progressively in patients whose baseline eGFR was <90 mL/min/1.73 m² (from 70.0 to 71.5 mL/min/1.73 m²; P < .001), and this increase was generalized across different stages of CKD. The trend of eGFR amelioration was consistent irrespective of sofosbuvir usage. Multivariate adjusted analysis demonstrated that baseline eGFR >90 mL/min/1.73 m² was the only factor independently associated with significant slope coefficient differences of eGFR (-1.98 mL/min/1.73 m²; 95% confidence interval, -2.24 to -1.72; P < .001). The use of sofosbuvir was not an independent factor associated with eGFR change.

CONCLUSIONS

Both sofosbuvir and non-sofosbuvir-based regimens restored renal function in CHC patients with CKD, especially in those with significant renal function impairment.

Emergence of resistance against direct acting antivirals in chronic HCV patients: A real-world study

Interferon/Ribavirin therapy has been replaced by Direct Acting Antivirals (DAAs) due to emergence of Resistance Associated Variants (RAVs) and decrease Sustain Virologic Response (SVR). Current study investigated treatment response of Sofosbuvir and Ribavirin in chronic HCV patients. Total 256 HCV patients with genotype 1a, 2 and 3a received sofosbuvir/ribavirin according to international standards. HCV RNA presence in serum was used as marker for end treatment response (ETR) and sustain virologic response after 24 weeks of treatment (SVR24) in each case. Response to treatment with SOF + RBV was found statistically significant among different HCV genotypes (GT) as out of 47 HCV GT1 patients 42(89.36%) resulted into good ETR but 4(9.52%) of these relapsed and 5(10.63%) led into virologic failure. 5(100%) HCV GT2 patients resulted into SVR24 whereas, out of 204 HCV GT3 patients 194(95.69%) achieved good ETR however, 8(4.12%) of these relapsed and 10(4.90%) resulted in to virologic failure. Efficacy of therapy was found non-significant in treatment naïve and treatment experienced patients as in this study out of 145 treatment naïve patients 139(95.86%) achieved good ETR where 4(2.87%) relapsed while 6(4.13%) led into virologic break through on the other hand among 111 treatment experienced patients 102(91.89%) resulted into good ETR but 8(7.84%) relapsed whereas 9(8.10%) lead into virologic failure. Current study also propose that various liver and spleen complications/liver cirrhosis are related to response of HCV patients to SOF + RBV therapy whereas, variables like old age, gender is not compromising treatment response to DAAs therapy. Various mild side effects encountered by patients during treatment were fatigue, insomnia, headache, nausea, burning body, diarrhea, cough. Overall, this study reported 89.45% efficacy of SOF + RBV regime in chronic HCV Pakistani patients. Current study suggests hunting for possible reasons of resistance so that SOF + RBV therapy may not share the same fortune as previous therapies in near future.

Design, chemical synthesis and antiviral evaluation of 2'-deoxy-2'-fluoro-2'-C-methyl-4'-thionucleosides

Nucleoside analogues represent an historically accomplished class of antiviral drug. Notwithstanding this, new molecular scaffolds are required to overcome their limitations and evolve pharmacophore space within this established field. Herein, we develop concise synthetic access to a new 2'-deoxy-2'-fluoro-2'-C-methyl-4'-thionucleoside chemotype, including the ProTide form of the uridine analogue. Biological evaluation of these materials in the Hepatitis C replicon assay shows little activity for the canonical pyrimidine forms, but the phosphoramidate of 2'-deoxy-2'-fluoro-2'-C-methyl-β-d-4'-thiouridine has an EC₅₀ of 2.99 μM. Direct comparison to the established Hepatitis C drug Sofosbuvir shows a 100-fold drop in activity upon substituting the furanose chalcogen; the reasons for this are as yet unclear.

High dose sofosbuvir and sofosbuvir-plus-ribavirin therapy inhibit Hepatitis E Virus (HEV) replication in a rabbit model for acute HEV infection

Hepatitis E virus (HEV) is an important cause of viral hepatitis worldwide and there is currently no FDA-approved anti-HEV drug. The commonly used drug ribavirin (RBV) could not achieve viral clearance in all patients and can induce drug resistance. Recent studies showed sofosbuvir (SOF) can inhibit HEV replication in vitro and has add-on effect when combined with RBV, but the effect of SOF against HEV infection remains controversial and the dosage of SOF warrants further exploration. In this study, a rabbit model for acute HEV infection was used to evaluate the effect of SOF at different doses against HEV genotype 3 and 4, and to compare the antiviral effect of SOF-plus-RBV therapy with RBV monotherapy. Virological parameters on fecal, serological and intrahepatic level were tested by real-time PCR and ELISA. Liver function tests and histopathological assays were performed. Both 200 mg/d and 300 mg/d SOF treatment inhibits HEV replication with relieved liver inflammation and declined levels of fecal HEV RNA, viremia and antigenemia. 300 mg/d SOF eliminated HEV replication while a short viral rebound was observed after 200 mg/d SOF treatment. The SOF-plus-RBV therapy also showed stronger anti-HEV effect than RBV monotherapy. Our study suggests that high dose of SOF showed better anti-HEV effect in the rabbit model. Moreover, the de novo SOF-plus-RBV therapy which eliminated acute HEV infection more efficiently than RBV monotherapy may serve as an alternative treatment strategy.

Comparative evaluation of different mathematical models for simultaneous UV spectrophotometric quantitative analysis of velpatasvir and sofosbuvir

Velpatasvir and sofosbuvir are new drugs prescribed in a combined pharmaceutical dosage form that pose a new challenge for the treatment of chronic hepatitis C. In this work, a comparative evaluation of the classical mathematical model, simultaneous equations, and the advanced mathematical model, partial least squares, for the spectrophotometric quantitative analysis of velpatasvir and sofosbuvir in bulk powder and in the new combined pharmaceutical dosage form was presented. The mathematical simultaneous equation method was used to resolve the overlap between velpatasvir and sofosbuvir. The absorbance and absorbativity values at 255 and 244.8 were used to construct two mathematical equations required for spectrophotometric quantitative analysis of the drugs under study. Partial least squares, an advanced mathematical tool dealing with the full spectral data of velpatasvir and sofosbuvir, was also introduced. An experimental design for the calibration sets and validation sets for the binary mixture of the drugs under study were created. The model was optimized based on a five-level, two-factor experimental design. Pre-processing of the spectral data was applied and resulted in the exclusion of the spectral region from 200 to 230 nm due to noise. The described methods were successfully applied to the spectrophotometric quantitative analysis of velpatasvir and sofosbuvir in Epclusa® tablets.

Innovative derivative/zero ratio spectrophotometric method for simultaneous determination of sofosbuvir and ledipasvir: Application to average content and uniformity of dosage units

An innovative simple, rapid and sensitive spectrophotometric method was developed for the simultaneous analysis of sofosbuvir (SOF) and ledipasvir (LED) in their combined dosage forms. Sofosbuvir with ledipasvir (SOF/LED) as a combined dosage form was tried at the pandemic COVID 19 crisis. This technique has the advantages of both zero order and first order spectrophotometry. The zero and first derivative amplitudes were measured at 274.2 nm for SOF (zero crossing point of LED in first derivative spectrum) and 314 nm for LED (zero crossing point of SOF in first derivative spectrum) over the concentration range of 2.0-50.0 μg mL^-1 with coefficients of determination (R²) > 0.9999 for both drugs and mean percentage recoveries of 100.25 ± 1.61 and 99.85 ± 0.99 for SOF and LED; respectively. This original method was validated according to ICH requirements and statistically compared to published comparison methods. This method was applied to estimate the average content and the uniformity of dosage units of SOF/LED combined dosage form according to British Pharmacopeia requirements.

Outreach onsite treatment with a simplified pangenotypic direct-acting anti-viral regimen for hepatitis C virus micro-elimination in a prison

BACKGROUND

Prisoners are at risk of hepatitis C virus (HCV) infection, especially among the people who inject drugs (PWID). We implemented an outreach strategy in combination with universal mass screening and immediate onsite treatment with a simplified pan-genotypic direct-acting antivirals (DAA) regimen, 12 wk of sofosbuvir/velpatasvir, in a PWID-dominant prison in Taiwan.

AIM

To implement an outreach strategy in combination with universal mass screening and immediate onsite treatment with a simplified pan-genotypic DAA regimen in a PWID-dominant prison in Taiwan.

METHODS

HCV-viremic patients were recruited for onsite treatment program for HCV micro-elimination with a pangenotypic DAA regimen, 12 wk of sofosbuvir/ velpatasvir, from two cohorts in Penghu Prison, either identified by mass screen or in outpatient clinics, in September 2019. Another group of HCV-viremic patients identified sporadically in outpatient clinics before mass screening were enrolled as a control group. The primary endpoint was sustained virological response (SVR12, defined as undetectable HCV ribonucleic acid (RNA) 12 wk after end-of-treatment).

RESULTS

A total of 212 HCV-viremic subjects were recruited for HCV micro-elimination campaign; 91 patients treated with sofosbuvir/Ledipasvir or glecaprevir/ pibrentasvir before mass screening were enrolled as a control. The HCV micro-elimination group had significantly lower proportion of diabetes, hypertension, hyperlipidemia, advanced fibrosis and chronic kidney diseases, but higher levels of HCV RNA. The SVR12 rate was comparable between the HCV micro-elimination and control groups, 95.8% (203/212) vs 94.5% (86/91), respectively, in intent-to-treat analysis, and 100% (203/203) vs 98.9% (86/87), respectively, in per-protocol analysis. There was no virological failure, treatment discontinuation, and serious adverse event among sofosbuvir/velpatasvir-treated patients in the HCV micro-elimination group.

CONCLUSION

Outreach mass screening followed by immediate onsite treatment with a simplified pangenotypic DAA regimen, sofosbuvir/velpatasvir, provides successful strategies toward HCV micro-elimination among prisoners.

Investigation of the effect of verapamil on the regional absorption of sofosbuvir from rabbit intestine in situ

PURPOSE

Sofosbuvir, a nucleotide antiviral drug, is a Biopharmaceutics Classification System (BCS) class III prodrug suffering from limited intestinal absorption due to its high hydrophilicity and low intestinal permeability. This research aims to investigate the luminal stability of Sofosbuvir, the influence of anatomical site on its intestinal absorption and the effects of verapamil on such absorption.

METHOD

The study utilized in situ rabbit intestinal perfusion technique to examine absorption of Sofosbuvir from duodenum, jejunum, ileum and ascending colon. This was conducted both with and without verapamil.

RESULTS

The luminal stability study showed that Sofosbuvir was subjected to premature degradation with varying fractions degraded from the different intestinal segments. The in situ perfusion data showed incomplete absorption of Sofosbuvir from small and large intestinal segments. The recorded values of the absorptive clearance per unit length (Pe.A/L) of Sofosbuvir were 0.026, 0.0075, 0.0026, & 0.054 ml/min.cm for duodenum, jejunum, ileum, and ascending colon, respectively. The Pe.A/L values were ordered as colon > duodenum > jejunum > ileum. This is the opposite rank of P-gp content in the different intestinal segments. The recorded values of the length required for complete Sofosbuvir absorption (L95%) were 29.58, 128.47, 949.2 and, 13.63 cm for duodenum, jejunum, ileum, and ascending colon, respectively. Co-perfusion with verapamil significantly increased Pe.A/L and reduced the L95% of Sofosbuvir from both jejunum and ileum (P-value < 0.05).

CONCLUSION

The results indicated that the absorptive clearance of Sofosbuvir was site dependent and associated with the content of P-glycoprotein, in addition to the expected drug interactions that can occur in polymedicated hepatitis C virus (HCV) infected patients.

Sofosbuvir/Velpatasvir for Hepatitis C Virus Infection: Real-World Effectiveness and Safety from a Nationwide Registry in Taiwan

INTRODUCTION

Pangenotypic direct-acting antivirals are expected to cure hepatitis C virus (HCV) in more than 95% of treated patients. However, data on the effectiveness and safety of sofosbuvir/velpatasvir (SOF/VEL) in Taiwan are limited. This study aims to characterize the patient population in the nationwide Taiwan Association for the Study of the Liver (TASL) HCV Registry and evaluate treatment outcome in Taiwanese patients receiving SOF/VEL.

METHODS

This study was a retrospective-prospective, observational, multicenter, real-world analysis. Adults with chronic hepatitis C were treated with SOF/VEL 400/100 mg ± ribavirin for 12 weeks. The primary outcome was sustained virologic response 12 weeks after end of therapy (SVR12). Factors associated with not achieving SVR12 were evaluated using logistic regression and covariate analysis. Safety was also assessed.

RESULTS

In total, 3480 patients were included: 86.8% genotype 1/2, 2.8% genotype 3, 0.1% genotype 4/5, 9.6% genotype 6; unclassified, 0.8%; 12.2% compensated cirrhosis; 3.3% decompensated cirrhosis; and 15.8% chronic kidney disease. Overall SVR12 rate was 99.4% (genotype 1, 99.5%; genotype 2, 99.4%; genotype 3, 96.9%; genotype 4, 100%; genotype 6, 99.7%). SVR12 rates among patients with compensated cirrhosis, decompensated cirrhosis, and chronic kidney disease stages 4-5 were 99.5%, 100%, and 100%, respectively. There were 21 patients (0.6%) who did not achieve SVR12. Factors associated with failure were treatment adherence below 60%, high viral load, and genotype 3 (p < 0.001, p = 0.028, and p = 0.001, respectively). Adverse events occurred in 10% of patients; 0.6% were serious and one was related to treatment. Treatment discontinuation occurred in 0.3% of patients; none were treatment related. The estimated glomerular filtration rate remained stable throughout treatment and follow-up, regardless of baseline values and cirrhosis status.

CONCLUSION

SOF/VEL was highly effective and well tolerated in Taiwanese patients, irrespective of viral genotype, liver disease severity, and comorbidities.

Acute reversible rhabdomyolysis during direct-acting antiviral hepatitis C virus treatment: a case report

INTRODUCTION

Treatment of hepatitis C infection has evolved dramatically since 2011. Previous conventional therapy with interferon and ribavirin used to have a low sustained virological response rate of less than 40%. In the new direct-acting antiviral therapy era, a sustained virological response can be achieved in more than 90% of cases.

CASE PRESENTATION

We report a rare case of severe reversible acute rhabdomyolysis in a 31-year-old Saudi male patient with very long-chain acyl-coenzyme A dehydrogenase deficiency and chronic hepatitis C infection. The patient was clinically asymptomatic with no signs of decompensated liver disease. The patient received new direct-acting antiviral agents: sofosbuvir and daclatasvir. Fourteen days after initiation of direct-acting antiviral agents, the patient was found to have asymptomatic rhabdomyolysis. His creatine kinase peaked at 2572 IU/l, and he was treated conservatively; the direct-acting antiviral agents were discontinued and within 7 days, the patient's creatine kinase levels normalized.

CONCLUSION

This case highlights possible direct-acting antiviral agent-induced rhabdomyolysis in a patient with very-long-chain acyl-CoA dehydrogenase deficiency, presumably through alteration of mitochondrial membrane potential. Further studies are required to assess the possible impact and associations.

Effectiveness of Sofosbuvir and Daclatasvir in treatment of Hepatitis-C: An experience of tertiary care hospital in Karachi

Objective:

To assess the effectiveness of Sofosbuvir (SOF) and Daclatasvir (DCV) in patients with chronic hepatitis C (CHC), compensated cirrhosis (CC) and decompensated cirrhosis (DCLD) either treatment naïve or experienced.

Methods:

This was a prospective, observational study, conducted from January 2017 to December 2018 at Jinnah Postgraduate Medical Centre, Karachi. All patients above 12 years of age with detectable HCV RNA PCR were included. Patients were divided into three groups: CHC, CC and DCLD. SOF and DCV for 12 or 24 weeks were given. Ribavirin (RBV) was given to treatment experienced and cirrhotic patients. Primary outcome was End of Treatment Response (ETR) and secondary outcome was Sustained Virological Response (SVR) at post treatment week 12 or 24.

Results:

Total 300 patients with mean age of 40.49 ± 13.86 were enrolled. Majority were females 174 (58%). CHC were 200 (66.6%) while cirrhotic were 100 (33.4%). Treatment naïve patients were 267 (89%) and 33 (11%) patients were experienced. Most common genotype was 3 (83%). ETR was achieved in 292 (97.33%) and SVR in 265 (88.33%) patients respectively.

Conclusion:

SOF plus DCV with or without RBV is a highly effective treatment for chronic HCV and is still used in many centers of Pakistan. This regimen has excellent results for GT-3. The outcomes are mainly influenced by the presence or absence of cirrhosis.

An intelligent method based on feed-forward artificial neural network and least square support vector machine for the simultaneous spectrophotometric estimation of anti hepatitis C virus drugs in pharmaceutical formulation and biological fluid

This study proposed simple and reliable spectrophotometry method for simultaneous analysis of hepatitis C antiviral binary mixture containing sofosbuvir (SOF) and daclatasvir (DAC). This technique is based on the use of feed-forward artificial neural network (FF-ANN) and least square support vector machine (LS-SVM). FF-NN with Levenberg-Marquardt (LM) and Cartesian genetic programming (CGP) algorithms was trained to determine the best number of hidden layers and the number of neurons. This comparison demonstrated that the LM algorithm had the minimum mean square error (MSE) for SOF (1.59 × 10^-28) and DAC (4.71 × 10^-28). In LS-SVM model, the optimum regularization parameter (γ) and width of the function (σ) were achieved with root mean square error (RMSE) of 0.9355 and 0.2641 for SOF and DAC, respectively. The coefficient of determination (R²) value of mixtures containing SOF and DAC was 0.996 and 0.997, respectively. The percentage recovery values were in the range of 94.03-104.58 and 94.04-106.41 for SOF and DAC, respectively. Statistical test (ANOVA) was implemented to compare high-performance liquid chromatography (HPLC) and spectrophotometry, which showed no significant difference. These results indicate that the proposed method possesses great potential ability for prediction of concentration of components in pharmaceutical formulations.

Identification of a novel replication-competent hepatitis C virus variant that confers the sofosbuvir resistance

Despite the excellent antiviral potency of direct-acting antivirals (DAAs) against hepatitis C virus (HCV), emergence of drug-resistant viral mutations remains a potential challenge. Sofobuvir (SOF), a nucleotide analog targeting HCV NS5B - RNA-dependent RNA polymerase (RdRp), constitutes a key component of many anti-HCV cocktail regimens and confers a high barrier for developing drug resistance. The serine to threonine mutation at the amino acid position 282 of NS5B (S282T) is the mostly documented SOF resistance-associated substitution (RAS), but severely hampers the virus fitness. In this study, we first developed new genotype 1b (GT1b) subgenomic replicon cells, denoted PR52D4 and PR52D9, directly from a GT1b clinical isolate. Next, we obtained SOF-resistant and replication-competent PR52D4 replicon by culturing the replicon cells in the presence of SOF. Sequencing analysis showed that the selected replicon harbored two mutations K74R and S282T in NS5B. Reverse genetics analysis showed that while PR52D4 consisting of either single mutation K74R or S282T could not replicate efficiently, the engineering of the both mutations led to a replication-competent and SOF-resistant PR52D4 replicon. Furthermore, we showed that the K74R mutation could also rescue the replication deficiency of the S282T mutation in Con1, another GT1b replicon as well as in JFH1, a GT2a replicon. Structural modeling analysis suggested that K74R might help maintain an active catalytic conformation of S282T by engaging with Y296. In conclusion, we identified the combination of two NS5B mutations S282T and K74R as a novel RAS that confers a substantial resistance to SOF while retains the HCV replication capacity.

Real-life experience of treating HCV co-infection among HIV-infected population in Egypt: single-center experience

BACKGROUND

Liver disease has emerged as a leading cause of death among PLHIV coinfected with HCV.

METHODS

A retrospective study involving all HCV viremic patients coinfected with HIV who presented to HCV/HIV multidisciplinary clinics located at Embaba fever hospital. Patients were assigned to receive DAAs according to the national treatment guidelines. The primary endpoint was SVR12.

RESULTS

Of the 519 patients enrolled, 38.73% LTFU; either not initiated (n = 170) or did not complete the treatment (n = 31). The main identified reasons behind LTFU were schedule conflict (19%) or hospitalization (13%). Among 318 patients who completed their DAAs course, nine patients had a relapse after the end of treatment and 97% had attained SVR12. There were significant differences among different virological response groups in baseline factors including smoking (p = 0.005), history of dental procedure (p = 0.007), CD4 count (p = 0.007), and HIV viral load (p = <0.001). Among responders (n = 309), there was a significant reduction of baseline hemoglobin and significant improvement of baseline platelets (p = 0.005) at on-treatment week 8. Baseline necro-inflammatory markers showed significant improvement across follow-up time points (p < 0.001).

CONCLUSIONS

DAAs are an effective and safe choice to treat HCV in PLHIV. Social stigma could be a major cause for lacking adherence to follow-up visits.Abbreviations: ALT: Alanine Aminotransferase; ARV: Antiretroviral treatment; AST: Aspartate Aminotransferase; DAAs: Direct acting antivirals; ARVs: antiretroviral therapy; EMR: Eastern Mediterranean region; HCV: Hepatitis C virus; kPa: Kilopascal; LTFU: Patient lost to follow up; NCCVH: The National Committee for Control of Viral Hepatitis; PWID: People who inject drugs; SVR: Sustained virological response;UNAIDS: The Joint United Nations Programme on HIV/AIDS.