Curing Chronic Hepatitis C: A Cost Comparison of the Combination Simeprevir Plus Sofosbuvir vs. Protease-Inhibitor-Based Triple Therapy.

INTRODUCTION: Interferon-free, multi-direct acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) infection is highly effective and well tolerated, but costly. To gain perspective on the evolving economics of HCV therapy, we compared the cost per cure of a multi-DAA regimen with the prior standard of triple therapy. MATERIAL AND METHODS: Patients infected with HCV genotype 1 who were treated through the University of Colorado Hepatology Clinic between May 2011 and December 2014 comprised the study population. The multi-DAA regimen of simeprevir plus sofosbuvir (SMV/SOF) was compared to the triple therapy regimen consisting of peginterferon and ribavirin, with either boceprevir or telaprevir (TT). Sustained-virologic response (SVR) rates, total costs per treatment and adverse events were recorded. Total cost per SVR were compared for the two treatments, controlling for patient demographics and clinical characteristics. RESULTS: One hundred eighty-three patients received SMV/SOF (n = 70) or TT (n = 113). Patients receiving SMV/SOF were older, more treatment experienced, and had a higher stage of fibrosis. SVRs were 86% and 59%, average total costs per patient were $152,775 and $95,943, and average total costs per SVR were $178,237 vs. $161,813.49 for SMV/SOF and TT groups, respectively. Medication costs accounted for 98% of SMV/SOF and 85% of TT treatment costs. CONCLUSION: The high cure rate of multi-DAA treatment of HCV is offset by the high costs of the DAAs, such that the cost per cure from TT to multi-DAA therapy has been relatively constant. In order to cure more patients, either additional financial resources will need to be allocated to the treatment of HCV or drug costs will need to be reduced.

Priapism induced by boceprevir-CYP3A4 inhibition and α-adrenergic blockade: case report.

A 44-year-old white man presented to the emergency department with a 3-day history of priapism requiring a surgically performed distal penile shunt. A drug-drug interaction is the suspected cause whereby CYP3A4 inhibition by boceprevir led to increased exposures of doxazosin, tamsulosin, and/or quetiapine, resulting in additional α-adrenergic blockade.

Optimizing hepatitis C virus treatment through pharmacist interventions: Identification and management of drug-drug interactions.

AIM: To quantify drug-drug-interactions (DDIs) encountered in patients prescribed hepatitis C virus (HCV) treatment, the interventions made, and the time spent in this process. METHODS: As standard of care, a clinical pharmacist screened for DDIs in patients prescribed direct acting antiviral (DAA) HCV treatment between November 2013 and July 2015 at the University of Colorado Hepatology Clinic. HCV regimens prescribed included ledipasvir/sofosbuvir (LDV/SOF), paritaprevir/ritonavir/ombitasvir/dasabuvir (OBV/PTV/r + DSV), simeprevir/sofosbuvir (SIM/SOF), and sofosbuvir/ribavirin (SOF/RBV). This retrospective analysis reviewed the work completed by the clinical pharmacist in order to measure the aims identified for the study. The number and type of DDIs identified were summarized with descriptive statistics. RESULTS: Six hundred and sixty four patients (83.4% Caucasian, 57% male, average 56.7 years old) were identified; 369 for LDV/SOF, 48 for OBV/PTV/r + DSV, 114 for SIM/SOF, and 133 for SOF/RBV. Fifty-one point five per cent of patients were cirrhotic. Overall, 5217 medications were reviewed (7.86 medications per patient) and 781 interactions identified (1.18 interactions per patient). The number of interactions were fewest for SOF/RBV (0.17 interactions per patient) and highest for OBV/PTV/r + DSV (2.48 interactions per patient). LDV/SOF and SIM/SOF had similar number of interactions (1.28 and 1.48 interactions per patient, respectively). Gastric acid modifiers and vitamin/herbal supplements commonly caused interactions with LDV/SOF. Hypertensive agents, analgesics, and psychiatric medications frequently caused interactions with OBV/PTV/r + DSV and SIM/SOF. To manage these interactions, the pharmacists most often recommended discontinuing the medication (28.9%), increasing monitoring for toxicities (24.1%), or separating administration times (18.2%). The pharmacist chart review for each patient usually took approximately 30 min, with additional time for more complex patients. CONCLUSION: DDIs are common with HCV medications and management can require medication adjustments and increased monitoring. An interdisciplinary team including a clinical pharmacist can optimize patient care.

Variant Inosine Triphosphatase Phenotypes Are Associated With Increased Ribavirin Triphosphate Levels.

Individuals with lower inosine triphosphatase (ITPA) enzyme activity have a reduced likelihood of experiencing hemolytic anemia during hepatitis C virus (HCV) treatment containing ribavirin (RBV). Because ITPA degrades purines and RBV is a purine analogue, it is conceivable that ITPA activity may affect intracellular RBV concentrations. Here we assessed the association between ITPA activity phenotype and concentrations of RBV triphosphate (RBV-TP) in red blood cells (RBCs) during HCV treatment. RBV-TP was quantified in the RBCs of 177 HCV-infected individuals at a median (range) of 84 (19 to 336) days into HCV treatment that included RBV. Mean (SD) RBV-TP concentrations were 92.8 (51.6), 101.3 (53.5), 184.8 (84.5), and 197.7 (64.6) pmol/106 cells for 100%, 60%, 30%, and ≤10% ITPA activity groups, respectively. Overall, RBV-TP was approximately 2-fold higher in patients with ≤30% ITPA activity compared to 100% activity (P < .0001). Despite higher RBV-TP levels, individuals with variant ITPA phenotypes had less anemia. The 100% activity group had, on average, a -2.20 g/dL drop in hemoglobin vs -1.43 g/dL (P = .04) for 60% activity, -1.14 g/dL (P = .008) for 30% activity, and -0.70 g/dL (P = .06) for ≤10% activity. This finding of higher RBV-TP concentrations in RBCs in ITPA variants was unexpected given that ITPA activity-deficient individuals have a reduced likelihood of RBV-induced anemia. It also refutes the hypothesis that the mechanism by which ITPA variants are protected against anemia is due to lower RBV-TP levels in RBCs.

The frequency of adjusted renal dosing of tenofovir DF and its effects on patient outcomes.

Tenofovir disoproxil fumarate (TDF), a nucleotide reverse transcriptase inhibitor used in the treatment of human immunodeficiency virus (HIV) and hepatitis B, is renally eliminated and has been associated with renal toxicities. Dose adjustments are recommended for patients with creatinine clearance (CrCL) <50 mL/min. We retrospectively determined the frequency in which HIV clinic providers adjusted TDF doses in patients with CrCL <50 mL/min over a 2-year period and compared clinical outcomes in patients who had TDF dose adjustments based on CrCL <50 mL/min versus those who did not. Thirty-nine patients with CrCL <50 mL/min were identified. Dose-adjusted patients (N = 9) continued their TDF-based antiretroviral regimens for 21 months longer following the first CrCL < 50 mL/min (P = .0193) and had gains in CD4 cell counts over 12 months (P = .0009). There were no statistically significant differences in CrCL or percentage of patients with detectable HIV-1 RNA at 6 and 12 months following first CrCL <50 mL/min in those who did versus did not have a TDF dose adjustment. In summary, HIV providers often failed to dose-adjust TDF in patients with CrCL <50 mL/min, but dose-adjusted patients appeared to stay on their TDF-based regimens longer and have greater gains in CD4 cells. Larger, prospective studies are needed to validate these results.

Curing Chronic Hepatitis C: A Cost Comparison of the Combination Simeprevir Plus Sofosbuvir vs. Protease-Inhibitor-Based Triple Therapy

ABSTRACT Introduction. Interferon-free, multi-direct acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) infection is highly effective and well tolerated, but costly. To gain perspective on the evolving economics of HCV therapy, we compared the cost per cure of a multi-DAA regimen with the prior standard of triple therapy. Material and methods. Patients infected with HCV genotype 1 who were treated through the University of Colorado Hepatology Clinic between May 2011 and December 2014 comprised the study population. The multi-DAA regimen of simeprevir plus sofosbuvir (SMV/SOF) was compared to the triple therapy regimen consisting of peginterferon and ribavirin, with either boceprevir or telaprevir (TT). Sustained-virologic response (SVR) rates, total costs per treatment and adverse events were recorded. Total cost per SVR were compared for the two treatments, controlling for patient demographics and clinical characteristics. Results. One hundred eighty-three patients received SMV/SOF (n = 70) or TT (n = 113). Patients receiving SMV/SOF were older, more treatment experienced, and had a higher stage of fibrosis. SVRs were 86% and 59%, average total costs per patient were $152,775 and $95,943, and average total costs per SVR were $178,237 vs. $161,813.49 for SMV/SOF and TT groups, respectively. Medication costs accounted for 98% of SMV/SOF and 85% of TT treatment costs. Conclusion. The high cure rate of multi-DAA treatment of HCV is offset by the high costs of the DAAs, such that the cost per cure from TT to multi-DAA therapy has been relatively constant. In order to cure more patients, either additional financial resources will need to be allocated to the treatment of HCV or drug costs will need to be reduced.