Generic sofosbuvir and daclatasvir for treatment of hepatitis C virus infection in patients with sickle cell disease

Background and purpose of the study Sickle cell disease (SCD) patients are at a high risk of chronic liver disease (CLD) due to chronic viral hepatitis infection such as hepatitis C virus (HCV) infection, iron overload, and sickle cell hepatopathy. Nowadays, several oral direct-acting antiviral drugs (DAAs) have been developed and approved by the FDA for hepatitis C treatment. However, the safety and efficacy of DAAs in SCD patients remain insufficiently explored. Purpose of the study To evaluate the efficacy and safety of administration of generic sofosbuvir (SOF) and daclatasvir (DCV) for 12 weeks in SCD patients infected with HCV. Methods A retrospective study included 38 SCD patients infected with HCV treated with generic SOF (400 mg) and DCV (60 mg) for 12 weeks without ribavirin. The effectiveness of the HCV treatment was assessed by the sustained virologic response (SVR) at 24 weeks after the end of the treatment (SVR24). Results The SVR24 rate was 100% (38/38).There were insignificant alterations in hemoglobin and total bilirubin levels during HCV treatment or at end of treatment (EOT). The number of anemic patients who needed blood transfusion two weeks before HCV treatment, at week 4 of treatment, and at EOT was 11 (28.9%), 3 (8%), and 1 (3%) respectively. Moreover, the reductions in serum transaminase levels from baseline were statistically significant compared to the EOT. Conclusion Generic SOF and DCV regimens appear to be safe and effective in the treatment of chronic HCV in patients with SCD.


Introduction
Sickle-cell disease (SCD), one of the commonest hemoglobinopathy worldwide, is an autosomal recessive trait caused by the presence of a mutated form of hemoglobin S (Hb S)), which results in hemolytic anemia and necessitates regular blood transfusions for these patients.Although the prevalence of transfusion-acquired illnesses has dramatically dropped in recent years due to more effective donor screening measures, these patients are nonetheless at high risk of acquiring hepatitis C virus (HCV) infection through blood transfusion [1].
Vaso-occlusive crises (VOC), acute chest syndrome, infections, strokes, renal failure, gallstones, and an acute worsening of anemia due to splenic sequestration and/ or aplastic, hyperhemolytic, and megaloblastic crises are among the consequences that can result from SCD [2,3].Furthermore, if treatment for the HCV infection is not received, there is an increased chance of these patients acquiring chronic liver disease (CLD), liver cirrhosis, hepatocellular carcinoma (HCC), and other liver complications [4].In addition, the presence of chronic HCV infection and the extent of iron overload are also strong predictors of liver fibrosis progression [5].
Therefore, to avoid liver complications and to improve morbidity and mortality in such individuals, effective chelation therapy and treatment for HCV infection are required [6].Previously, pegylated interferon (peg-IFN) plus ribavirin (RBV) was the recommended course of treatment for chronic HCV infection.Peg-IFN and RBV studies have shown that individuals with SCD and HCV infection have lower sustained virological response (SVR) rates and increase RBV-associated anemia [7,8].Additionally, RBV use has been linked to hemolysis, which raises the need for blood transfusions and can exacerbate iron excess [9].
Recently, direct-acting antiviral drugs (DAAs) have demonstrated excellent cure in HCV patients regardless of HCV genotype or response to prior treatment [10,11].However, DAAs have not been extensively used in patients with hemoglobinopathies in real-life settings, and only very few clinical trials of DAAs in chronic HCV infection have been reported in patients with hemoglobinopathies [12][13][14][15].There are currently limited clinical studies on the effectiveness and safety of DAAs in chronic HCV patients with SCD.
The aim of our study was to evaluate the efficacy and safety of administration of generic sofosbuvir (SOF) and daclatasvir (DCV) for 12 weeks in SCD patients infected with HCV.

Patients
This retrospective study included 38 chronic HCV patients with a confirmed diagnosis of SCD who were treated with generic SOF/DCV for 12 weeks.These patients were recruited from viral hepatitis treatment centers affiliated to the National Committee for Control of Viral Hepatitis (NCCVH) in Egypt between 2018 and 2019.Diagnosis of SCD based on history and hemoglobin electrophoresis.Eligible patients aged 18 years or older with seropositivity of HCV antibodies and detectable HCV RNA for at least 6 months, were either treatmentnaïve or treatment-experienced and had any body mass index (BMI) or any stage of hepatic fibrosis as assessed by fibrosis-4 score (FIB-4) calculation and compensated cirrhosis (Child-Pugh score A5 up to B8).Patients were ineligible for the study if they had a co-infection with hepatitis B virus, human immunodeficiency virus; they suffered from an advanced liver disease (decompensated CLD as determined by a history of ascites or the presence of Child-Pugh score B9 and Child-Pugh class C cirrhosis), or they had a history of active HCC or extra-hepatic malignancy.

Medications
SCD patients with HCV were treated with generic SOF in a dose of 400 mg and 60 mg of generic DCV, both once daily, for 12 weeks, depending upon the inclusion and exclusion criteria of the national protocol issued by the HCV treatment program in Egypt during the recruitment period.None of these patients received RBV due to the RBV-induced hemolysis that could lead to more profound anemia.
SCD patients with HCV were treated with hydroxyl urea (HDX).The dosage was based on weight, laboratory results, and response to treatment.The starting dose was 10-15 mg/kg/day as single dose; monitoring patient ' s blood cell count q2weeks.Dose escalation by 5 mg/kg/ day q12wk.Dose not to be exceeded 35 mg/kg/day.

Endpoints and outcome measures
The primary endpoints of the study were to evaluate the efficacy and safety of generic SOF/DCV in chronic HCV patients with SCD.Outcomes measured included the SVR rate, defined as undetectable HCV RNA by quantitative polymerase chain reaction assay (Cobas Amplicor, HCV Roche, Branchburg, NJ, USA, v 2.0), with a lower limit of quantification (LLOQ) of 15 IU/mL at week 24 after the EOT (SVR24).SVR24 has been widely accepted and recognized as an indicator of therapeutic success [18].During the treatment period, patients were followed up clinically, underwent laboratory monitoring and safety profile evaluation as scheduled every 4 weeks.Safety was assessed by monitoring adverse events (AEs),eg., the occurrence of VOC and laboratory tests.
The study was performed in accordance with the principles of Good Clinical Practice (GCP) and the Declaration of Helsinki and it was approved by the Institutional Review Board (IRB) of the Faculty of Medicine, Cairo University (N-120-2020).All patients provided their written informed consent to participate in this study before receiving HCV treatment.

Statistical analysis
Descriptive analysis was carried out and the results were presented as mean ± standard deviation (SD) for continuous variables or as proportions (percentages) for categorical variables.Laboratory variables were compared before and after DAAs treatment using a paired t-test.The software STATA 13.1 (Stata Crop, College Station, TX) was used for statistical analyses.If the P-value was less than 0.05, it was deemed significant.

Results
Table 1 displayed the baseline characteristics of the included SCD patients.The mean age (± SD) of SCD patients was 34 (± 9) years and the majority was males (57.9%, 22/38).All the SCD patients were HCV treatment-naïve (100%, 38/38) and non-cirrhotic.Their mean BMI was 29 kg/m 2 .Hypertension was reported in 1 (3%) patient and none of these patients reported type 2 diabetes mellitus.
All participants completed 12 weeks of SOF/DCV treatment, and none of them discontinued treatment due to adverse events.They had a minimum follow-up of 24 weeks after EOT and SVR24 was achieved in all patients (100%, 38/38).
At baseline, the mean levels of hemoglobin (Hb) and total bilirubin in the whole cohort were 9.7 g/dl and 0.93 mg/dl, respectively.There were insignificant alterations in hemoglobin and total bilirubin levels during HCV treatment or at EOT.The mean hemoglobin level was 9.84 g/dl and 9.63 g/dl at week 4 of treatment and at EOT, respectively, with a mean difference of -2.80 (14.1) g/dl, whereas the mean level of total bilirubin was 0.93 mg/dl and 1 mg/dl at baseline and EOT, respectively, as shown in Table (2).Of the 38 patients, 29 (76.3%)suffered from anemia grade 2 (Hb levels ≤ 10 g/dl), and their mean level hemoglobin was 9.2 g/dl.Grade 1 hyperbilirubinemia (≤ 1.5 × ULN) was detected in 6 (15.8%) patients at baseline.Meanwhile, the number of anemic patients who needed blood transfusion two weeks before HCV treatment, at week 4 of treatment, and at EOT was 11 (28.9%), 3 (8%), and 1 (3%) respectively.
Moreover, the reductions in serum ALT and AST levels from baseline were statistically significant compared to EOT.There was an insignificant change in WBCs or platelet count after 4 weeks of treatment and 12 weeks of treatment (EOT),with average WBCs and platelet values during follow-up visits of 6.1 x (10 9 /L) and 233 x (10 3 / μL), respectively, as shown in Table 2.
Patients were categorized according to the presence of anemia (Hb ≤ 10 g/dl) on starting HCV treatment into anemic and patients with normal hemoglobin.12 weeks of treatment (EOT), patients with no baseline anemia showed a significant decline in hemoglobin level and platelet count (P = 0.01 and 0.04, respectively), however, patients who already had anemia at baseline showed a non-significant decline in platelet count (P = 0.12) and a non-significant increase in hemoglobin level (P = 0.11).In contrast, patients with baseline anemia showed a significant decline in ALT levels (P = 0.02), however, patients who already had anemia at baseline did not show that decline (P = 0.17) as shown in Table 3.
Similarly, SCD patients with HCV were subdivided into two groups based on the presence of baseline hyperbilirubinemia; patients with normal total bilirubin and patients with rise total bilirubin.After 12 weeks of treatment (EOT), there was a significant decline in ALT levels in patients with normal total bilirubin at baseline (39.7 (32.4) mg/dl vs. 20.4(15.3) mg/dl, P = 0.01).However, patients with baseline rise in total bilirubin showed

Discussion
SCD patients with HCV infection were regarded as a difficult to-treat population due to peg-IFN, and RBV treatments were contraindicated in these patients because of the reduction of rates of SVR and increasing RBV-associated anemia [19].Nowadays, chronic HCV infection is treated using combinations of oral DAA drugs without peg-IFN and RBV.These therapies are not contraindicated in patients with hemoglobinopathies, and the  European Association for the Study of the Liver (EASL) recommends their use in patients with hemoglobinopathies [20].
The present real-world study, including 38 SCD patients treated for 12 weeks with generic SOF/DCV, shows an SVR24 rate of 100%.The patients' high response rates to treatment were similar to those observed in individuals treated with various DAA combinations, whether they had hemoglobinopathies or not.A multicenter phase III randomized trial evaluating the safety and effectiveness of elbasvir/grazoprevir administered for 12 weeks in HCV patients with thalassemia (38%), sickle cell anemia (18%), hemophilia A/B, or von Willebrand disease (44%), revealed higher SVR rates (93.5%, 100/107) [14].A pooled analysis of phase II and III clinical trials reported 184 chronic HCV patients with bleeding disorders who were administered either SOF/RBV or SOF/ ledipasvir (LDV) with or without RBV.The overall SVR12 rate was 85% [13].Moreover, an open-label, single-center study enrolled 10 patients with HCV genotype 1 or 4 infection who received treatment for SCD.They received SOF/LDV (400 mg/100mg) for 12 weeks (non-cirrhotic patients) or 24 weeks (cirrhotic patients).The overall SVR rate was 90% (9/10) [21].
On the other hand, a few real-world studies have involved individuals with hemoglobinopathies receiving HCV DAA medications.Higher SVR rates were reported in a smaller retrospective analysis involving 81 patients with hemoglobinopathies (b-thalassemia major [86%], sickle cell anemia/b-thalassemia [14%]) and HCV infection (38%) [22].In that analysis, 11 patients were treated with DAAs.Nine of them had failed a previous IFN-based course, and seven had advanced fibrosis.All patients attained SVR.In addition, our data were similar to a real-world study including 27 patients (25 with sickle cell disease, 1 with β-thalassemia, and 1 with hemoglobin D-Punjab) treated for 8 or 12 weeks with SOF-based regimens, which showed an SVR12 rate of 93%, with only one virological failure [23].Another real-world study included 139 HCV patients with hemoglobinopathies (thalassemia major [82%], sickle-cell thalassemia [5%], thalassemia intermedia [2%], and sickle-cell anemia [1%]) received different oral DAA medications and completed 12 weeks of follow-up after the end of treatment.The overall SVR12 rate was 93.5% (130/139) [15].
Moreover, our patients were adherent to HCV treatment, and no treatment-related adverse events were observed that necessitated premature treatment discontinuations.Most importantly, none of SCD patients with HCV experienced a sickle cell crisis 6 months prior to HCV therapy, during SOF/DAC treatment or in the subsequent 6-month follow-up period.
As expected, patients showed a significant reduction in serum ALT and AST post-DAAs treatment comparable to baseline, and this was in agreement with a study performed earlier [15].This could be explained by the reduction in the necroinflammatory status of the liver, which was associated with HCV elimination by DAAs [24,25].
Anemia and hyperbilirubinemia were the most frequent laboratory abnormalities in SCD due to underlying disease and treatment-related adverse event.In our study, generic SOF/DCV regimen without RBV was generally safe in SCD patients with HCV.We found that no significant change in the level of hemoglobin throughout HCV treatment, and the number of SCD patients who needed blood transfusions significantly decreased at week 4 of treatment and at EOT in comparison to baseline denoting that HCV treatment did not worsen the patients' anemia.Furthermore, the total bilirubin levels at EOT were not significantly different from baseline, and in patients with baseline hyperbilirubinemia, the total bilirubin level did not increase even after HCV therapy was completed.This result was consistent with previous research [15,23,26].
There are several limitations to this study.First, a smaller number of patients were included in the study.Second, the retrospective design of the study and there are some missing data, such as serum ferritin and levels of HB S and F. Third, a short follow-up period; therefore, prospective studies with prolonged follow-up are needed.

Conclusion
Non-cirrhotic, treatment-naive SCD patients infected with chronic HCV experienced a favorable treatment response with generic SOF/DCV for 12 weeks.Therefore, HCV treatment should be prioritized in this special group to achieve the World Health Organization's (WHO) goal of eliminating HCV infection as a public health threat.

Table 1
Characteristic features of the SCD patients with HCV Unless otherwise stated numerical data are expressed as mean (SD) Abbreviations: BMI Body mass index, HCV Hepatitis C virus, RNA Ribonucleic acid, PCR Polymerase chain reaction, SCD Sickle cell disease, SVR24 Sustained virologic response 24 completing SOF/DAC treatment (EOT); however this improvement was approaching a significant level (2.38 ( 0.83) mg/dl vs. 1.62 (0.72) mg/dl, P = 0.08) as shown in Table4.

Table 2
Changes in laboratory parameters of the SCD patients with HCV Abbreviations: AST Aspartate aminotransferase, ALT Alanine aminotransferase, EOT End of treatment, HCV Hepatitis C virus, SCD Sickle cell disease, WBCs White blood cells * P-value between baseline and week 4 of treatment ** P-value between week 4 of treatment andweek 12 of treatment (EOT)

Table 3
Comparative analysis between anemic and non-anemic SCD patients with HCV regarding laboratory results at baseline and 12 weeks of treatment (EOT)Abbreviations: AST Aspartate aminotransferase, ALT Alanine aminotransferase, EOT End of treatment, HCV Hepatitis C virus, SCD Sickle cell disease, WBCs White blood cells

Table 4
Comparative analysis between SCD patients with normal total bilirubin and patients with rise total bilirubin at baseline regarding laboratory results in baseline and 12 weeks of treatment (EOT)Abbreviations: AST Aspartate aminotransferase, ALT Alanine aminotransferase, EOT End of treatment, HCV Hepatitis C virus, SCD Sickle cell disease, WBCs White blood cells