Drug-drug interactions in hepatitis C virus treatment: Do they really matter?

HCV Antiviral Drugs Have the Potential to Adversely Perturb the Fetal-Maternal Communication Axis through Inhibition of CYP3A7 DHEA-S Oxidation

The hepatitis C virus (HCV) poses a great risk to pregnant people and their developing fetus, yet no HCV antiviral treatment guidelines have been established. While there has been a substantial increase in the development of HCV antivirals, the effect they have on the developing fetus remains poorly defined. Many of these drugs are metabolized through the cytochrome P450 CYP3A pathway, which is mediated by cytochrome P450 3A7 (CYP3A7) in the fetus and developing infant. In this study, we sought to investigate the effect HCV antivirals have on CYP3A7 metabolism, as this CYP enzyme plays a vital role in proper fetal and neonatal development. Of the 13 HCV antivirals we investigated, 8 (∼62%) inhibited CYP3A7 metabolic activity by 50% or more at a concentration of 20 µM. Furthermore, paritaprevir, asunaprevir, simeprevir, danoprevir, and glecaprevir all had observed half-maximal inhibitory concentrations between the range of 10 and 20 µM, which is physiologically relevant in comparison with the Km of dehydroepiandrosterone-sulfate (DHEA-S) oxidation (reported to be between 5 and 20 µM). We also discovered that paritaprevir is a time-dependent inhibitor of CYP3A7, which shifts the IC50 ∼twofold from 11 µM to 5 µM. Upon further characterization, paritaprevir inactivates DHEA-S metabolism by CYP3A7, with KI and Kinact values of 4.66 µM and 0.00954 minute-1, respectively. Depending on treatment plan and off-label drug use, HCV treatment could adversely affect the fetal-maternal communication axis by blocking fetal CYP3A7 metabolism of important endogenous hormones. SIGNIFICANCE STATEMENT: The prevalence of HCV in pregnant people is estimated at between 1% and 8% of the global population, yet little to no information exists about the risk antiviral treatment poses to the developing fetus. There is a potential risk of drugs adversely affecting mother-fetal communication by inhibiting fetal hepatic CYP3A7, an integral enzyme for estriol production. We discovered that five HCV antivirals inhibited DHEA-S metabolism by CYP3A7, and paritaprevir inactivated the enzyme. Our studies demonstrate the potential threat these drugs pose to proper fetal development.

Italian Real-World Analysis of the Impact of Polypharmacy and Aging on the Risk of Multiple Drug-Drug Interactions (DDIs) in HCV Patients Treated with Pangenotypic Direct-Acting Antivirals (pDAA)

Purpose

The study aims at investigating the impact of polymedication and aging in the prevalence of multiple drug-drug interactions (DDIs) on HCV patients treated with sofosbuvir/velpatasvir (SOF/VEL) or glecaprevir/pibrentasvir (GLE/PIB).

Patients and Methods

This is a retrospective analysis based on administrative data covering around 6.9 million individuals. Patients treated with SOF/VEL or GLE/PIB over November 2017-March 2020 were included. Index date corresponded to SOF/VEL or GLE/PIB first prescription during such period; patients were followed up for treatment duration. Analyses were then focused on patients with ≥2 comedications at risk of multiple DDIs. The severity and the effect of multiple DDI were identified using the Liverpool University tool.

Results

A total of 2057 patients with SOF/VEL and 2128 with GLE/PIB were selected. Mean age of SOF/VEL patients was 58.5 years, higher than GLE/PIB ones (52.5 years) (p < 0.001), and patients >50 years were more present in SOF/VEL vs GLE/PIB cohorts: 72% vs 58%, (p < 0.001). Most prescribed co-medications were cardiovascular, alimentary and nervous system drugs. Proportion of patients with ≥2 comedications was higher in SOF/VEL compared to GLE/PIB cohort (56.5% vs 32.3%, p < 0.001). Those at high-risk of multiple DDIs accounted for 11.6% (N = 135) of SOF/VEL and 19.6% (N = 135) of GLE/PIB (p < 0.001) patients with ≥2 comedications. Among them, the potential effect of DDI was a decrease of DAA serum levels (11% of SOF/VEL and GLE/PIB patients) and an increased concentration of comedication serum levels (14% of SOF/VEL and 42% of GLE/PIB patients).

Conclusion

This real-world analysis provided a thorough characterization on the burden of polymedication regimens in HCV patients treated with SOF/VEL or GLE/PIB that expose such patients to an increased risk of DDIs. In our sample population, SOF/VEL regimen was more frequently detected on elderly patients and on those with ≥2 comedications at risk of multi-DDI, ie, among patients characterized by higher rates of comorbidities and polypharmacy.

Repurposing of antiviral drugs for COVID-19 and impact of repurposed drugs on the nervous system

The recent pandemic, Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has devastated humanity and is continuing to threaten us. Due to the high transmissibility of this pathogen, researchers are still trying to cope with the treatment and prevention of this disease. Few of them were successful in finding cure for COVID-19 by including repurposed drugs in the treatment. In such pandemic situations, when it is nearly impossible to design and implement a new drug target, previously designed antiviral drugs could help against novel viruses, referred to as drug repurposing/redirecting/repositioning or re-profiling. This review describes the current landscape of the repurposing of antiviral drugs for COVID-19 and the impact of these drugs on our nervous system. In some cases, specific antiviral therapy has been notably associated with neurological toxicity, characterized by peripheral neuropathy, neurocognitive and neuropsychiatric effects within the central nervous system (CNS).

Liver Transplantation Using Hepatitis C Virus-Viremic Donors Into Hepatitis C Virus-Aviremic Recipients as Standard of Care

Liver transplantation (LT) using allografts from hepatitis C virus (HCV)-viremic/nucleic acid testing-positive donors' (DNAT+) organs into HCV-aviremic recipients (rHCV-) has been limited owing to nearly universal HCV transmission and concerns regarding availability, safety, and efficacy post-LT with direct-acting antiviral (DAA) therapy. We report our experience of LT using DNAT+ organs into rHCV- as a routine standard of care. Following verification of DAA access, absence of critical drug-drug interactions (DDIs) with DAAs, and informed consent, allocated DNAT+ organs were offered to patients on the waiting list for LT irrespective of recipient HCV status. Between June 2018 and December 2019, 292/339 rHCV- received an LT. Forty-seven patients were excluded from analysis because of recipient HCV viremia, refusal to receive DNAT+ organs, or inability to receive DAA therapy post-LT. Of these 292 patients, 61 rHCV- received DNAT+ livers (study group), and 231 rHCV- received DNAT- (aviremic donors [nuclear acid test-negative donors]) livers (control group). Recipient and donor characteristics as well as 1-year post-LT patient and graft survival were similar between groups. In the study group, 4 patients died, and 1 patient required retransplantation within the first year post-LT (all unrelated to HCV); 56 patients received DAA therapy, with a median time from LT to the start of DAA treatment of 66.9 days (interquartile range [IQR], 36-68.5), and 51 patients completed DAA treatment, all achieving sustained virologic response for 12 or more weeks (SVR-12) (1 patient required retreatment owing to relapse following initial DAA therapy). No patients had evidence of fibrosing cholestatic hepatitis or extrahepatic manifestations of HCV. This report indicates that transplantation of DNAT+ livers into rHCV- and subsequent DAA therapy is associated with clinical outcomes comparable to those achieved with DNAT- allografts.

Comorbidities and concomitant medications in patients with chronic hepatitis C virus infection receiving second-generation direct-acting antiviral regimens in Belgium: an observational study

Objective

To describe comorbidities and concomitant medications in patients initiating treatment for hepatitis C virus (HCV) infection with direct-acting antiviral (DAA) regimens in Belgium.

Methods

This was a noninterventional, observational, multicenter study of data from patient charts. Adult patients with HCV infection receiving second-generation DAA therapy were included. Comorbidities were assessed at the time of HCV treatment initiation. Concomitant medications were recorded at the time of diagnosis and at treatment initiation. Potential clinically relevant drug-drug interactions (DDIs) were assessed based on information available at www.hep-druginteractions.org. The primary objective was to describe concomitant medication use ; secondary objectives were to describe modifications in concomitant therapies and comorbidities.

Results

405 patients were included. A total of 956 comorbidities were reported by 362 patients (median, 2 ; range, 0-15). The most common comorbidities were hypertension (27.2%) ; HIV coinfection (22.5%), and type 2 diabetes mellitus (14.3%). Overall, 1455 concomitant medications were being taken by 365 patients (90.1% ; median, 3 ; range 0-16). The most common concomitant medications were psycholeptics (28.6%), antiviral agents (24.2%), and medications for acid-related disorders (21.0%) Overall, 74/365 (20.3%) patients receiving a concomitant medication required an adaptation to their concomitant medication. The medications that most frequently required change were drugs for acid-related disorders (n = 14) and antiviral drugs (n = 5) ; those that were most frequently stopped were lipid-modifying drugs (n = 25) and drugs for acid-related disorders (n = 13).

Conclusion

Physicians are aware of the potential for DDIs with DAAs, but improved alignment between clinical practice and theoretical recommendations is required.