Daclatasvir Research Articles

Daclatasvir as a hepatitis C infection treatment option: an up-to-date evaluation

ABSTRACT Introduction Globally, it is estimated that 290,000 patients infected with hepatitis C virus (HCV) died from hepatitis C consequences, including cirrhosis and hepatocellular carcinoma in 2019. Although daclatasvir (DCV), combined with sofosbuvir (SOF), is effective in HCV patients, the new pan-genotypic combinations are considered by many as more cost-effective and successful in eradicating HCV infection. Areas covered This review discusses the safety, efficacy, and cost-effectiveness of DCV as an HCV treatment option based on real-world studies and pharmacoeconomic evaluations. Expert opinion Real-life studies suggest that SOF/DCV has acceptable sustained virological response and can be used successfully to manage HCV. Nonetheless, the use of SOF/DCV is limited by the longer treatment duration in genotype (GT)-3 patients and the need for ribavirin (RBV) in treatment-experienced patients which increases the likelihood of adverse effects. DCV is likely to remain as a therapeutic option for the management of GT-1, GT-2, and GT-4 patients in resource limited settings, while GT-3 patients are more likely to benefit from RBV-free direct-acting antiviral combinations such as SOF/velpatasvir for 12 weeks or glecaprevir/pibrentasvir for 8 weeks. The introduction of generics for these new pan-genotypic drugs would likely eliminate the need for SOF/DCV in the near future.

Selection dynamics of HCV genotype 3 resistance-associated substitutions under direct-acting antiviral therapy pressure.

The chronic hepatitis C (CHC) treatment is currently based on the use of direct-acting antivirals (DAAs), and patients infected with hepatitis C virus genotype 3 (GT3) have emerged as a more difficult-to-cure population. The NS5A inhibitor daclatasvir (DCV) and sofosbuvir (SOF), an NS5B viral polymerase inhibitor, are among the drugs that compose more effective and safer treatment regimens. The virus genetic variability is related to resistance-associated substitutions (RASs) that adversely impact DAAs effectiveness. The aims of this study were to analyze the association of NS5A and NS5B RASs and other clinical factors with DAAs regimens effectiveness in patients with GT3 CHC infection. This was a prospective cohort study performed in a Brazilian university hospital. Individuals older than 18 years with GT3 CHC treated with SOF+DCV ± ribavirin (RBV) or SOF+peginterferon (PEG)+RBV were included. Blood samples were collected at baseline and post-treatment. A total of 121 patients were included. Sustained virological response rates were 87.6% for the SOF+DCV ± RBV group and 80.0% for the SOF+PEG+RBV arm. Cirrhosis, prior treatment with interferon/PEG+RBV, and baseline NS5A RAS were associated with higher risk of treatment failure. The NS5A analysis suggested that A30K, Y93H, and RAS at site 62 were related to failure. Interestingly, a likely compensatory effect was shown between A30K and A62T. Emergence of Y93H was always associated with RAS at position 62. The RASs dynamics comprehension is an important tool to indicate more effective treatment for GT3 patients.

S3264 A Hepatitis C (HCV) Infection Treatment Dilemma

Introduction: HIV/HCV coinfection increases liver-related morbidity and mortality. This special population should be prioritized for treatment. Currently available direct-acting antivirals (DAAs) are safe and effective, but there are many drug interactions (DIs) to consider. Carbamazepine (CBZ) is contraindicated with all available DAAs. Patients that require treatment for HCV but cannot stop CBZ do not have a clear treatment option. Patients may be transitioned to newer antiepileptics that do not have the same contraindications, but some patients are unwilling or unable to change medications. Case Description/Methods: Patient is a 59-year-old man with well-controlled HIV on HAART, well-controlled trigeminal neuralgia on CBZ, anemia, and non-cirrhotic (FibroScan 12 kPa), treatment naïve, chronic HCV genotype 1a. Due to DIs between DAAs and CBZ, multiple attempts were made to discontinue CBZ but were unsuccessful. Neurosurgery offered surgical gamma knife management, but up to 40% of patients still require CBZ post-procedure. An initial plan for daclatasvir (DAC)-sofosbuvir (SOF)-ribavirin (RBV) was proposed, but DAC is no longer available in the US. Patient was followed conservatively but developed thrombocytopenia and progression of fibrosis (FibroScan 14.7kPa). Given worsening liver condition, shared decision-making was performed, and patient completed 16 weeks of Glecaprevir (GLE)/pibrentasvir (PIB) + SOF 400mg with 4 weeks of ezetimibe 10mg stopping when the viral load was undetectable. Patient was instructed to start the ezetimibe with the GLE/PIB + SOF but was hesitant to take it due to adverse reaction to statins in the past. At 4 weeks of treatment, HCV viral load was still detectable. Patient was re-educated on the purpose of the ezetimibe and reassured it was not a statin. He took it from week 4-8 of treatment. At week 8, HCV viral load was undetectable. Patient achieved SVR 12 and showed improvement of his FibroScan score to 9.6 kPa. Discussion: GLE/PIB is pangenotypic, has a high barrier to resistance, and has been proven safe and effective in combination with SOF + RBV in MAGELLAN 3 for 16 weeks duration. Patient has history of anemia, making RBV undesirable. Ezetimibe blocks the NPC1L receptor which potentially inhibits HCV entry into the hepatocyte. HCV relies on cell-to-cell transmission, so we chose to add ezetimibe 10mg daily until HCV not detected. There is a need for larger studies to determine the applicability of this case study to other patients.

Detection of Occult Hepatitis C Virus Infection in Egyptian Patients Who Achieved a Sustained Virologic Response to Direct-Acting Antiviral Agents.

Occult hepatitis C virus (HCV) infection (OCI) is diagnosed based on the detection of HCV-RNA in non-serum reservoirs, such as peripheral blood mononuclear cells (PBMCs) and/or hepatocytes with undetectable HCV-RNA in the serum. The current study was designed to shed more light on the presence of occult HCV in a population of cases who achieved an SVR after receiving treatments for HCV-infection and its significance. This cross-sectional study evaluated 111 chronic HCV patients treated at Theodor Bilharz Research Institute, Egypt and achieved a sustained virological response (SVR) 12 -24 weeks after treatment with Direct acting antiviral drugs (DAAs). The treatment lasted 12 or 24 weeks using generic medications including Sofosbuvir (SOF) 400 mg/day and Daclatasvir (DCV) 60 mg/day ± weight-based Ribavirin (RBV) 600-1000 mg/day. After achieving the SVR 12 -24 weeks, all patients were subjected to clinical examination and full laboratory investigations. All the candidates were assessed for fibrosis pre/post-treatment by transient elastography (Fibroscan©). Eighty-seven patients (78.4%) received dual therapy (SOF/DCV) and 24 patients (21.6%) received triple therapy (SOF/DCV/RBV). One hundred and seven patients received the regimen for 12 weeks (96.4%) and only four patients received the regimen for 24 weeks (3.6%). All patients were examined in terms of HCV RNA in plasma and PBMCs. Nine patients (8.1%) were positive for PBMCs HCV RNA. The presence of Occult HCV infection (OCI) was significantly correlated with age, level of AFP, and the degree of liver stiffness. The OCI was present in 8.1% of the patients who achieved an SVR 12 - 24 weeks. These patients were mostly aged and with elevated AFP and advanced fibrosis. Monitoring and follow-up of those patients may help to assess the outcomes.

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

BackgroundThe 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.ResultsThe 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.ConclusionSOF 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.

A degron system targeting endogenous PD-1 inhibits the growth of tumor cells in mice.

Recently, targeted protein degradation systems have been developed using the ubiquitin-proteasome system. Here, we established Programmed cell death-1 (PD-1) knockdown mice as a model system for subjecting endogenous mouse proteins to the small molecule-assisted shutoff (SMASh) degron system. SMASh degron-tagged PD-1-mCherry in Jurkat cells and CD3+ splenocytes were degraded by the NS3/4A protease inhibitors, asunaprevir (ASV) or grazoprevir (GRV). Growth of MC-38 colon adenocarcinoma cells injected in Pdcd1-mCherry-SMASh homozygous knock-in (KI) mice was repressed by ASV or GRV. Moreover, growth of MC-38 cells was suppressed in wild-type mice transplanted with KI bone marrow cells after GRV treatment. This is the first study to use a degron tag targeting an endogenous mouse protein in vivo. Our experimental system using the SMASh degron may be employed for treating diseases and characterizing the cellular functions of essential proteins.

HPLC BASED PROCEDURE DEVELOPMENT FOR MONITORING ACETIC ACID IN DACLATASVIR DRUG

A process for determination of acetic acid (AAD) in Daclatasvir (DAC) active medicinal ingredients applying HPLC technique was developed. The process involved separation AAD using Phenomenex made Synergi polar RP-80A column with gradient manner of elution, employing mobile solvent phase with 0.1% phosphoric acid (solvent A) and acetonitrile (solvent B), at flow velocity of 0.6 ml/min and UV sensor examination at 210 nm. AAD linearity range was 5.01289μg/ml to 30.07733μg/ml with sensitivity of 1.65425μg/ml (LOD) and 5.01289μg/ml (LOQ). Accuracy towards AAD recoveries were 111.3 to 113.0%, 86.7 to 94.4% and 90.9 to 95.7%, and precision towards AAD’s RSD was 1.197% and 3.367%. The projected HPLC process could be applied to analysis of AAD in DAC active medicinal ingredients with sharp selectivity, better sensitivity, and high point accuracy.

A Reversible Chemogenetic Switch for Chimeric Antigen Receptor T Cells.

As a revolutionary cancer treatment, the chimeric antigen receptor (CAR) T cell therapy suffers from complications such as cytokine release syndromes and T cell exhaustion. Their mitigation desires controllable activation of CAR-T cells that is achievable through regulatory display of CARs. By embedding the hepatitis C virus NS3 protease (HCV-NS3) between the single-chain variable fragment (scFv) and the hinge domain, we showed that the display of anti-CD19 scFv on CAR-T cells was positively correlated to the presence of a clinical HCV-NS3 inhibitor asunaprevir (ASV). This novel CAR design that allows the display of anti-CD19 scFv in the presence of ASV and its removal in the absence of ASV creates a practically reversible chemical switch. We demonstrated that the intact CAR on T cells can be repeatedly turned on and off by controlling the presence of ASV in a dose dependent manner both in vitro and in vivo, which enables delicate modulation of CAR-T activation during cancer treatment.

A Reversible Chemogenetic Switch for Chimeric Antigen Receptor T Cells**

AbstractAs a revolutionary cancer treatment, the chimeric antigen receptor (CAR) T cell therapy suffers from complications such as cytokine release syndromes and T cell exhaustion. Their mitigation desires controllable activation of CAR‐T cells that is achievable through regulatory display of CARs. By embedding the hepatitis C virus NS3 protease (HCV‐NS3) between the single‐chain variable fragment (scFv) and the hinge domain, we showed that the display of anti‐CD19 scFv on CAR‐T cells was positively correlated to the presence of a clinical HCV‐NS3 inhibitor asunaprevir (ASV). This novel CAR design that allows the display of anti‐CD19 scFv in the presence of ASV and its removal in the absence of ASV creates a practically reversible chemical switch. We demonstrated that the intact CAR on T cells can be repeatedly turned on and off by controlling the presence of ASV in a dose dependent manner both in vitro and in vivo, which enables delicate modulation of CAR‐T activation during cancer treatment.

Three Smart and Original Spectrophotometric Data Processing Ratio Techniques for Resolving the Partial Overlapped Spectra of the Binary Antiviral Mixture Daclatasvir/Sofosbuvir: Application to Combined Dosage Form Darvoni® Tablets.

The combination of daclatasvir (DCV) and sofosbuvir (SFV) is now widely used as an ideal treatment for hepatitis C virus (HCV) infection. For this purpose, simple, sensitive, rapid, and smart spectrophotometric methods were developed and validated for the determination of these drugs in their combined dosage form. Development of smart, sensitive, low-cost spectrophotometric methods for the determination of DCV and SFV in their combined dosage form. Ratio subtraction (RS), amplitude modulation (AM), and mean-centering spectrophotometric methods were established and validated for the estimation of SFV in the presence of DCV without previous separation, using a unified regression equation. A linearity range of 2.5-25.0 µg/mL was confirmed for the direct measurement of DCV at 316 nm (because there is no interference from SFV. Linearity was confirmed over a concentration range of 10.0-80.0 µg/mL for SFV. The current methods were established according to the ICH recommendations, and specificity was examined by testing synthetic mixtures of both drugs. They were tested on their tablet dosage form, and a good recovery was obtained. The current methods proved to be simple, specific, and economical. A statistical study of the current ratio approaches and published methods showed there was no apparent statistical variation. Both antiviral agents can be quantified in the presence of each other by the current methods, which is a significant time- and cost-saving benefit of the developed methods. This benefit is even more important in the case of the combined dosage form (Darvoni® tablets) for the pharmaceutical market.

Assessment of Renal Function in Egyptian HCV Patients Treated with Combination Therapy of Sofosbuvir and Daclatasvir

BACKGROUND: According to the most recent Egyptian demographic health census, the estimated Hepatitis C virus (HCV) prevalence in the 15–59 age range was 14.7%. Globally, the incidence of renal impairment in HCV-positive individuals is 40% higher than in HCV-negative patients. HCV-induced renal impairment can range from mild-to-severe, and it frequently complicates the treatment outcome of HCV infection. AIM: This study aimed to explore the changes in renal function in Egyptian HCV patients treated with a combination of Sofosbuvir (SOF) and Daclatasvir (DCV). METHODOLOGY: Six hundred and eleven chronic HCV patients treated with SOF-DCV were enrolled. Patients were classified into three groups according to their baseline renal function: unimpaired group (estimated glomerular filtration rate [eGFR] ≥ 90 ml/min/1.73 m2), mildly impaired group (eGFR of ≥60–89 ml/min/1.73 m2), and moderately impaired group (eGFR of ≥30–59 ml/min/1.73 m2). Every month during treatment and at 24 weeks after treatment (sustained virological response 24), the eGFR level was evaluated. RESULTS: Our findings indicated that the eGFR level was significantly increased (p < 0.001) in all groups during the treatment but subsequent decline (p < 0.001) in all groups was documented after 6 months of treatment. Multivariate analysis identified baseline renal impairment (<90 ml/min/1.73 m2, p < 0.001) and baseline anemia (p < 0.001) as independent risk factors for renal function deterioration at the end of treatment. CONCLUSION: Clinical physicians should closely monitor renal function in patients treated with SOF-DCV. Furthermore, anemia therapy prior to SOF-DCV treatment should be recommended.

Successful treatment of hepatitis C genotype 4 using sofosbuvir, daclatasvir, simeprevir and ribavirin in Egyptian patients with direct-acting antiviral agent treatment failure.

IntroductionIn chronic hepatitis C virus (HCV) patients in whom prior direct-acting antiviral agent (DAA) treatment had failed, outcomes after retreatment are optimal. Combination of sofosbuvir (SOF), daclatasvir (DCV), simeprevir (SIM), and ribavirin (RBV) in treatment experienced patients is recommended in current guidelines despite insufficient data. Our aim is to determine the efficacy and safety of SOF, DCV, SIM plus RBV in HCV infected patients who failed prior DAA treatment.Material and methodsOne hundred and seventeen patients who failed to respond to SOF containing regimens were randomized according to previous response to therapy to non-responders and relapsers. Duration of therapy depends on fibrosis stages. SOF, DCV, SIM and weight based RBV 12 weeks for F1 and F2 (group I) and 24 weeks for F3 and F4 (group II).ResultsIn the non-responder group, a sustained virologic response (SVR) occurred in 100% in group I (F1 and F2) and 97% in group II (F3 and F4). Relapse was 3% in group II (F3 and F4). No patients from either group had breakthrough or non-response. In relapsers SVR was 100% in group I (F1 and F2) and 96% in group II (F3 and F4). Breakthrough, relapse and non-response were 2%, 4%, 2% respectively only in group II (F3 and F4).ConclusionsCombining multiple DAAs with different viral targets may be effective treatment protocol in previous non-responders and relapsers with short durations of treatment.

The impact of genetic variations in sofosbuvir metabolizing enzymes and innate immunity mediators on treatment outcome in HCV-infected patients

Hepatitis C virus (HCV) is the leading cause of liver diseases worldwide. At present, combinations of different classes of direct-acting antiviral agents (DAAs) are used as treatment options for HCV, in which sofosbuvir (SOF) is the common DAA among different therapeutic regimes. In Egypt, SOF plus daclatasvir (DCV) is the widely used anti-HCV treatment protocol. Herein, we aimed to assess the association between 3 single-nucleotide polymorphisms (SNPs) at the genes coding for 2 SOF metabolizing enzymes: histidine triad nucleotide-binding protein 1 (HINT1) rs4696/rs7728773 and nucleoside diphosphate kinase 1 (NME1) rs3760468, together with the most potent anti-HCV innate molecule, i.e., interferon lambda 3 (IFNL3) rs12979860 and the response to SOF/DCV in Egyptian patients chronically infected with genotype 4 (GT4). SNPs were genotyped using real-time PCR in DNA from patients who achieved sustained virological response (SVR) at 12 weeks post-SOF/DCV treatment (i.e., responders; n = 188), patients who failed to achieve SVR12 (i.e., non-responders; n = 109), and healthy controls (n = 62). Our results demonstrated that patients bearing HINT1 rs7728773 CT/TT (odds ratio 2.119, 95% CI 1.263–3.559, p = 0.005) and IFNL3 rs12979860 CC (odds ratio 3.995, 95% CI 2.126–7.740, p = 0.0001) were more likely to achieve SVR12. However, neither HINT1 rs4696 nor NME1 rs3760468 seems to contribute to the responsiveness to SOF/DCV. Binary regression analysis defined 5 predictor factors independently associated with SVR12: age, bilirubin, hemoglobin, early stages of fibrosis, and combined HINT1 rs7728773 and IFNL3 rs12979860 favorable and mixed genotypes (odds ratio 3.134, 95% CI 1.518–6.47, p = 0.002), and that was confirmed by the combined ROC curve for the 5 predictor factors (AUC = 0.91, 95% CI 0.869–0.95, P = 0.0001). In conclusion, these data suggest that the two SNPs have the potential in predicting the response rate to SOF/DCV treatment in patients infected with HCV GT4. This study is the first to investigate the pharmacogenetics of SOF metabolizing enzyme and introduce HINT1 rs7728773 as a novel SNP that predicts the treatment efficacy.

SPECTROPHOTOMETRIC METHODS FOR DETERMINATION OF SOFOSBUVIR AND DACLATASVIR IN PURE AND DOSAGE FORMS

Objective: Two simple, sensitive and accurate spectrophotometric methods have been developed for the determination of sofosbuvir (SOF) and daclatasvir (DAC) in pure forms and pharmaceutical formulations. Methods: The proposed methods are based on the oxidation of SOF and DAC by a known excess of cerium(IV) ammonium nitrate in sulphuric acid medium followed by determination of unreacted cerium(IV) by adding a fixed amount of indigo carmine (IC) and alizarin red S (ARS) dyes followed by measuring the absorbance at 610 and 360 nm, respectively. The experimental conditions affecting the reaction were studied and optimized. Results: The beer’s law was obeyed in the concentration ranges of 0.2-3.0, 0.2-4.0 for SOF and 0.5-4.5 and 0.5-5.0 μg/ml for DAC using IC and ARS methods, respectively with a correlation coefficient ≥ 0.9991. The calculated molar absorptivity values are 2.354 × 104, 1.933 × 104 for SOF and 1.786 × 104 and 2.015 × 104 L/mol. cm for DAC using IC and ARS methods, respectively u. The limits of detection and quantification are also reported. Intra-day and inter-day precision and accuracy of the methods have been evaluated. Conclusion: The methods were successfully applied to the assay of SOF and DAC in tablets and the results were statistically compared with those of the reference method by applying Student’s t-test and F-test. No interference was observed from the common tablet excipients. The accuracy and reliability of the methods were further ascertained by performing recovery studies using the standard addition method.

Efficacy and safety of sofosbuvir plus daclatasvir with or without ribavirin in treatment of Egyptian patients infected with chronic HCV (Single Centre Study)

Abstract Background and aim As indicated by the World Health Organization (WHO), Egypt is positioned as the country with the world’s highest prevalence of Hepatitis C virus (HCV). The current study was designed to describe the efficacy and safety of Sofosbuvir plus Daclatasvir with or without Ribavirin in treatment of chronic HCV in a cohort of Egyptian patients who were referred to the viral hepatitis unit in El -Fayoum general hospital. Methods This is a prospective descriptive cross sectional study that describes the effect of 12 weeks of daily Sofosbuvir (SOF) 400 mg plus Daclatasvir (DCV) 60 mg with or without ribavirin (RBV) with dose adjustment if indicated. It included 200 patients that fulfilled the inclusion and exclusion criteria and treated in El -Fayoum general hospital, El-Fayoum, Egypt. Results In the current study, concerning viral response, SVR12 rate was achieved by 92.5% in the overall patients (185/200); by 98% (98/100) in group I, and by 87% (87/100) in group II. Concerning safety and tolerability, The main adverse effects recorded during and after 12 weeks of treatments were fatigue (46%), (66%); headache (24%), (40%); gastrointestinal upset (15%), (43%); and nausea (10%), (15%) in group 1 and group 2, respectively. Only one female patient in group II developed HCC. All patients completed treatment till the end of course. Conclusion The current study suggested that treatment of SOF plus DCV with/without RBV for chronic HCV patients in Egypt was generally safe, well tolerated, and of high efficacy, reflecting the antiviral potency and high resistance barrier of the combination regimen.

Liver Targeting of Daclatasvir via Tailoring Sterically Stabilized Bilosomes: Fabrication, Comparative In Vitro/In Vivo Appraisal and Biodistribution Studies.

IntroductionHepatitis C virus (HCV) is a significant public health concern that threatens millions of individuals worldwide. Daclatasvir (DAC) is a promising direct-acting antiviral approved for treating HCV infection around the world. The goal of this study was to encapsulate DAC into novel polyethylene glycol (PEG) decorated bilosomes (PEG-BILS) to achieve enhanced drug delivery to the liver.MethodsDAC-loaded BILS were primed by a thin film hydrating technique. The study of the impact of various formulation variables on the properties of BILS and selection of the optimal formulation was generated using Design-Expert® software. The optimum preparation was then pegylated via the incorporation of PEG-6-stearate (5% w/w, with respect to the lipid phase).ResultsThe optimum PEG-BILS formulation, containing PL:SDC ratio (5:1), 5 mg cholesterol, and 30 min sonication, yielded spherical vesicles in the nanoscale (200±15.2 nm), elevated percent of entrapment efficiency (95.5±7.77%), and a sustained release profile of DAC with 35.11±2.3% release. In vivo and drug distribution studies revealed an enhanced hepatocellular delivery of DAC-loaded PEG-BILS compared to DAC-unPEG-BILS and DAC suspension, where DAC-PEG-BILS achieved 1.19- and 1.54 times the AUC0–24 of DAC-unPEG-BILS and DAC suspension, respectively. Compared with DAC-unPEG-BILS and DAC suspension, DAC-PEG-BILS delivered about 2 and 3 times higher DAC into the liver, respectively.ConclusionThe innovative encapsulation of DAC-PEG-BILS has a great potential for liver targeting.

Effective and Safe Daclatasvir Drug Exposures Predicted in Children Using Adult Formulations.

Sofosbuvir (SOF)/daclatasvir (DCV) is the direct-acting antiviral regimen of choice in many low- and middle-income countries for curative treatment of chronic hepatitis C virus (HCV) infection in adults, but data on the use of DCV in children are lacking. We performed a population pharmacokinetic (PK) analysis to predict DCV exposure in children treated with available adult formulations. DCV concentration data from HCV-infected adolescents receiving SOF/DCV [400/60 mg, once daily (OD)] who participated in a PK study in Egypt were used for model development. PK parameters were estimated using a population approach. Monte Carlo simulations were run for virtual children weighing 10 to <35 kg receiving 60 or 30 mg OD, and DCV exposures were compared with adults ranges. Seventeen HCV-infected adolescents (13 males) provided 151 DCV concentrations. Median (range) age was 14 (11-18) years and weight 50 (32-63) kg. In these adolescents receiving 60 mg DCV, median (interquartile range) DCV area under the concentration time curve 0 to 24 hours, maximum concentrations, and minimum concentrations were 11,130 (8140-14,690) ng·h/mL, 1030 (790-1220) ng/mL and 130 (110-220) ng/mL, respectively, compared with 10,343 (7661-14,095) ng·h/mL, 1132 (876-1518) ng/mL and 110 (55.7-192) ng/mL predicted in children 10 to <35 kg receiving 30 mg. The proportion of children with DCV exposures above the adult range rapidly increased for children <30 kg using 60 mg OD, similarly for children 10-14 kg using 30 mg. DCV 30 mg OD was predicted to achieve effective and safe exposures in children 14 to <35 kg, perhaps down to 10 kg. These results should be validated clinically. Low-cost available adult DCV formulations together with approved pediatric doses of SOF would expand global access to HCV treatment for children.

Complexation of daclatasvir by single isomer methylated β-cyclodextrins studied by capillary electrophoresis, NMR spectroscopy and mass spectrometry

In capillary electrophoresis an enantioseparation of daclatasvir (DCV) was observed in case of heptakis(2,6-di-O-methyl)-β-CD, heptakis(2-O-methyl)-β-CD and β-CD, while two peaks with a plateau were noted for heptakis(2,3,6-tri-O-methyl)-β-CD and heptakis(2,3-di-O-methyl)-β-CD indicating a slow equilibrium. Heptakis(6-O-methyl)-β-CD and heptakis(3-O-methyl)-β-CD yielded broad peaks. Nuclear magnetic resonance experiments including nuclear Overhauser effect-based techniques revealed inclusion complex formation for all CDs with the biphenyl ring of DCV within the cavity and the valine-pyrrolidine moieties protruding from the torus. However, in case of heptakis(2,6-di-O-methyl)-β-CD, heptakis(2-O-methyl)-β-CD and β-CD higher order structures with 1:3 stoichiometry were concluded, where the valine moieties enter additional CD molecules via the secondary side. Heptakis(2,3,6-tri-O-methyl)-β-CD and heptakis(2,3-di-O-methyl)-β-CD yielded primarily 1:1 complexes. Higher order complexes between DCV and heptakis(2,6-di-O-methyl)-β-CD were corroborated by mass spectrometry. Complex stoichiometry was not the reason for the slow equilibrium yielding the plateau observed in capillary electrophoresis, but structural characteristics of the CDs especially complete methylation of the secondary rim.

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.

Microelimination of hepatitis C in patients with chronic hemolytic anemias: a single-center experience

BackgroundPatients with chronic hemolytic anemias (CHA) are at a high risk for transfusion-transmitted infections. Various studies in Egypt have shown a prevalence of hepatitis C virus (HCV) infection in 24–37% of those patients. Elimination of hepatitis C virus (HCV) in patients with CHA would prevent early progression of liver disease. In this study, we aimed to assess the efficacy, safety, and tolerability of sofosbuvir (SOF) and daclatasvir (DAC) in the special population of HCV-infected patients with CHA. In this prospective study, 21 consenting hepatitis C patients were recruited and treated using ribavirin-free SOF/DAC regimen for either 12 or 24 weeks according to categorization of patients into easy or hard-to-treat in accordance with the national protocols. Sustained virological response was assessed by RT-PCR for HCV-RNA at 12 weeks post-treatment (SVR12). Any treatment-related adverse events were noted.ResultsAll patients were adherent to treatment with no discontinuation of therapy. SVR12 was achieved in 19 out of 21 patients (90.5%). There was a significant improvement in levels of ALT (p<0.009) after completion of therapy. On the other hand, the hemoglobin, total bilirubin, and ferritin levels showed a non-significant difference (p<0.501, p<0.542, and p<0.339, respectively). Moderate adverse events were observed in 2 out of 21 patients (9.5%), including sickling crisis and hepatic decompensation.ConclusionThe results of this study substantiate the favorable efficacy, safety, and tolerability of ribavirin-free direct-acting antivirals (DAAs) in the special population of HCV-infected patients with CHA. Micro-elimination of HCV in special patient populations allows for pragmatic delivery of care to patients with co-morbid conditions who are in most need for treatment and allows for achievement of global elimination of HCV worldwide.