Hepatic Pharmacokinetics and Pharmacodynamics With Ombitasvir/Paritaprevir/Ritonavir Plus Dasabuvir Treatment and Variable Ribavirin Dosage

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.

Intrahepatic Viral Kinetics During Direct-Acting Antivirals for Hepatitis C in Human Immunodeficiency Virus Coinfection: The AIDS Clinical Trials Group A5335S Substudy

BACKGROUND

Direct-acting antivirals (DAAs) targeting hepatitis C virus (HCV) have revolutionized outcomes in human immunodeficiency virus (HIV) coinfection.

METHODS

We examined early events in liver and plasma through A5335S, a substudy of trial A5329 (paritaprevir/ritonavir, ombitasvir, dasabuvir, with ribavirin) that enrolled chronic genotype 1a HCV-infected persons coinfected with suppressed HIV: 5 of 6 treatment-naive enrollees completed A5335S.

RESULTS

Mean baseline plasma HCV ribonucleic acid (RNA) = 6.7 log10 IU/mL and changed by -4.1 log10 IU/mL by Day 7. In liver, laser capture microdissection was used to quantify HCV. At liver biopsy 1, mean %HCV-infected cells = 25.2% (95% confidence interval [CI], 7.4%-42.9%), correlating with plasma HCV RNA (Spearman rank correlation r = 0.9); at biopsy 2 (Day 7 in 4 of 5 participants), mean %HCV-infected cells = 1.0% (95% CI, 0.2%-1.7%) (P < .05 for change), and DAAs were detectable in liver. Plasma C-X-C motif chemokine 10 (CXCL10) concentrations changed by mean = -160 pg/mL per day at 24 hours, but no further after Day 4.

CONCLUSIONS

We conclude that HCV infection is rapidly cleared from liver with DAA leaving <2% HCV-infected hepatocytes at Day 7. We extrapolate that HCV eradication could occur in these participants by 63 days, although immune activation might persist. Single-cell longitudinal estimates of HCV clearance from liver have never been reported previously and could be applied to estimating the minimum treatment duration required for HCV infection.

Fine-Needle Aspiration for the Evaluation of Hepatic Pharmacokinetics of Vaniprevir: A Randomized Trial in Patients With Hepatitis C Virus Infection

Fine-needle aspiration (FNA) for serial hepatic sampling may be an efficient and less invasive alternative to core needle biopsy (CNB), the current standard for liver tissue sampling. In this randomized, open-label trial in 31 participants with hepatitis C virus genotype 1 infection (NCT01678131/Merck protocol PN048), we evaluated the feasibility of using FNA to obtain human liver tissue samples appropriate for measuring hepatic pharmacokinetics (PK), using vaniprevir as a tool compound. The primary end point was successful retrieval of liver tissue specimens with measurable vaniprevir concentrations at two of three specified FNA time points. Twenty-nine patients met the primary end point and, therefore, were included in the PK analyses. Hepatic vaniprevir concentrations obtained with FNA were consistent with known vaniprevir PK properties. The shape of liver FNA and CNB concentration-time profiles were comparable. In conclusion, FNA may be effective for serial tissue sampling to assess hepatic drug exposure in patients with liver disease.

Development and validation of eco-friendly micellar-HPLC and HPTLC-densitometry methods for the simultaneous determination of paritaprevir, ritonavir and ombitasvir in pharmaceutical dosage forms

Ombitasvir, ritonavir and paritaprevir are three recently discovered directly acting antiviral drugs (DAADs) used in combined single dose tablet dosage form for treatment of hepatitis-C viral infections (HCV). The methods of analysis followed by quality control and research laboratories are required to be economic and fast; however, these methods can also produce huge amounts of chemical waste. In this study two fast, economic and green HPLC and HPTLC methods were validated for the simultaneous determination of the three drugs. For HPLC, isocratic elution used a mixture of micellar aqueous mobile phase consisting of (0.15 M sodium lauryl sulfate and 0.01 M sodium dihydrogen phosphate, pH 6.2) and ethanol (56:44). Elution was done on RP-C18 Kinetix® column (5 μm, 150 mm × 4.6 mm ID) at flow 1 mL min^-1 and 254 nm UV-detector. HPTLC separations were performed on Merck® (20 cm × 10 cm) aluminum HPTLC plates coated with silica gel 60F254 using a mobile phase, Methylene chloride: methanol: ethyl acetate: ammonia (25%), (5:1:3:1, v/v/v/v) respectively. The calibration curves were linear across ranges of 3-100 μg mL^-1 and 0.1-2 μg/spot for both HPLC and HPTLC methods, respectively. The two methods were applied successfully for the determination of the three drugs under study in their combined tablets dosage forms.

Is Human Papilloma Virus Associated with Breast Cancer? A Review of the Molecular Evidence

BACKGROUND

Although the association of human papillomavirus (HPV) with many cancers is well established, the involvement of HPV in breast cancer remains controversial. The purpose of this study is to perform a comprehensive review of the results and methods used to demonstrate that HPV markers are present in human breast cancer, and how well these studies fulfil the criteria for proving the viral etiology of a cancer.

STUDY DESIGN

We conducted a search for molecular studies published until November 2016 that relate human breast cancer to HPV.

RESULTS

Forty-three original molecular studies were found, some of which compared cases to nonneoplastic controls. Some investigations did not identify HPV in mammary tissue, but others identified it with different frequencies of positivity, varying between 1.2 and 86%. In most case-control studies (21/24 studies), positivity in cases was found to be higher than in controls, but odds ratios and confidence intervals were not reported.

CONCLUSION

The results are controversial. However, they arouse a great interest in the potential participation of HPV in breast carcinogenesis, but rather as an essential cause-effect participant, at least as a co-participant in some cases. The circumstance of HPV positivity in breast cancer can be criticized, but the elements that clearly demonstrate it in a number of cases are also relevant.