Trana Hussaini

Drug Interactions With Direct-Acting Antivirals for Hepatitis C: Implications for HIV and Transplant Patients

Objective: Review pharmacokinetics of new direct-acting antivirals (DAAs) for hepatitis C (HCV) infection and interactions with concomitant immunosuppressant and antiretroviral therapies (ART). Data Sources: MEDLINE (1948-January 2015), EMBASE (1964-January 2015), International Pharmaceutical Abstracts (1970-January 2015), Google, and Google Scholar were searched combining the terms simeprevir, sofosbuvir, ledipasvir, daclatasvir, paritaprevir, ABT-450, ombitasvir, dasabuvir, pharmacokinetics, drug interaction, drug metabolism, HIV, antiretroviral, immunosuppressant, transplant. Articles, conference proceedings, abstracts, and product monographs were reviewed. Study Selection and Data Extraction: Literature on pharmacokinetic or pharmacodynamic interactions with DAAs and immunosuppressants or ART was considered for inclusion. Pertinent information was extracted and summarized in the review. In the absence of data, pharmacokinetic and pharmacodynamic principles were used to predict the likelihood of interactions. Data Synthesis: DAA pharmacokinetics are reviewed and drug interaction data are presented with provision of management strategies. Fixed-dose combination paritaprevir/ritonavir/ombitasvir plus dasabuvir is most susceptible to drug interactions with immunosuppressants and ART mainly due to the influence of ritonavir on multiple enzymes. Simeprevir is also prone to drug interactions because of cytochrome P450(CYP) 3A4, CYP1A2, P-glycoprotein, and OATP1 involvement and is not recommended for use in combination with several HIV antiretrovirals (ARVs). Close therapeutic drug monitoring of calcineurin inhibitors is required with concomitant simeprevir. Few clinically significant interactions are expected with sofosbuvir or ledipasvir. Limited data suggest that daclatasvir may be coadministered with immunosuppressants but requires dose adjustments with certain ARVs. Conclusions: None of the DAAs are completely free of drug interactions. Awareness and management of drug interactions is critical to optimize outcomes and minimize adverse effects in these patient populations.

Therapeutic Drug Monitoring of Voriconazole and Posaconazole

Despite the availability of newer antifungal agents, invasive fungal diseases remain a leading cause of morbidity and mortality in immunocompromised patients. Voriconazole and posaconazole are two extended‐spectrum triazoles indicated for treatment and prophylaxis of invasive fungal diseases. Recently, there has been increased interest in the utility of therapeutic drug monitoring to optimize safety and efficacy of antifungals in an attempt to improve patient outcomes. We reviewed the pharmacokinetic and pharmacodynamic characteristics of voriconazole and posaconazole in the context of clinical indications for therapeutic drug monitoring. In addition, the most recent evidence examining the relationship between serum concentrations of voriconazole and posaconazole and their efficacy or toxicities was evaluated. This information was then integrated to formulate recommendations for use of therapeutic drug monitoring in clinical settings.

Therapeutic drug monitoring for triazoles: A needs assessment review and recommendations from a Canadian perspective

Therapeutic drug monitoring (TDM) is necessary for certain drugs to ensure that the levels are sufficient to be effective, but not so high as to cause adverse effects. This review summarizes the literature regarding TDM for newer-generation extended-spectrum triazoles, including when TDM may be necessary for each drug and why, and laboratory techniques used for the measurement of levels of these drugs. The document includes recommendations for the use of TDM for each triazole that is discussed.

Sofosbuvir-Based Antiviral Therapy Is Highly Effective In Recurrent Hepatitis C in Liver Transplant Recipients: Canadian Multicenter "Real-Life" Experience.

Background This study evaluates the efficacy, safety, and tolerability of regimens containing sofosbuvir (SOF) in the treatment of hepatitis C virus (HCV) recurrence in all genotypes in patients outside of clinical trials in all Canadian transplant centers. Methods One hundred twenty liver transplantation recipients from across Canada with HCV recurrence were started on SOF-based regimens (SOF + simeprevir ± ribavirin (RBV), n = 53; SOF + pegylated interferon + RBV, n = 25; SOF + RBV, n = 36; and SOF + ledipasvir, n = 6) between January and November 2014. Mean age 58 ± 6.85 years, majority (83%) were genotype 1, male (81%), and treatment experienced (82%). Twenty-seven percent had fibrosing cholestatic hepatitis/early aggressive HCV in the graft, and 48% had F3/4 fibrosis. The primary outcomes included patient and graft survival, on- and end-of-treatment response and sustained virological response at 12 weeks after treatment end (SVR12), and adverse events. Results One hundred thirteen of 120 (94%) patients were HCV RNA undetectable at end of treatment, and SVR12 was achieved in 102/120 (85%) patients, with 7 relapses, 1 nonresponder, and 10 deaths (liver-related complications). Sixty-three percent had HCV RNA levels below the lower limit of quantification at week 4. Serum creatinine levels remained stable throughout the treatment. Severe anemia occurred in 13% of patients, primarily in RBV-based regimens. Conclusions Sofosbuvir-based antiviral therapy for HCV recurrence after liver transplantation was well tolerated, with an overall high SVR12 rate (85%) including patients with severe disease recurrence and F3-4 cirrhosis. The response rate was higher (91%) in mild HCV recurrence, suggesting earlier treatment might be beneficial.

A review of direct-acting antivirals for the treatment of hepatitis C in patients with advanced chronic kidney disease

Historically, standard treatment of hepatitis C virus (HCV) infection in patients with renal impairment has been limited by low cure rates and poor tolerability. The introduction of direct-acting antivirals (DAAs) has revolutionized the treatment of HCV with impressive cure rates >90% and low rates of adverse events. Despite these major advancements, treatment of patients with HCV and advanced chronic kidney disease (CKD) is a major challenge due to the lack of efficacy and safety data in this patient population. The purpose of this review is to summarize the available data for efficacy and safety of the following DAAs in treating HCV patients with advanced Stage 4 and 5 CKD: simeprevir, sofosbuvir, ledipasvir, ombitasvir, paritaprevir, dasabuvir, grazoprevir, elbasvir and daclatasvir.

Concordance of sustained virologic response at weeks 4, 12 and 24 post-treatment of hepatitis c in the era of new oral direct-acting antivirals: A concise review.

The goal of treatment for chronic hepatitis C viral (HCV) infection is to cure the infection rather than suppress the virus. Historically, a sustained virological response (SVR) defined as undetectable HCV RNA at 24 weeks following the completion of treatment was considered the gold standard to define successful eradication of the virus as a primary endpoint in clinical trials. SVR measured at 12 weeks post-treatment has been shown to be highly concordant with SVR24 in trials of pegylated interferon and ribavirin. The appropriateness and durability of SVR12 as the efficacy endpoint with new oral direct-acting antivirals is less established. A literature search was performed using PubMed, EMBASE and CENTRAL databases to identify any studies that examined the concordance between SVR24 and earlier time points. Two studies and 4 abstracts were found that performed concordance analyses using positive and negative predictive values. Overall, SVR4 and SVR12 were highly concordant with SVR24 with high positive (> 97%) and negative (> 94%) predictive values; however there was a higher risk of HCV relapse occurring after post-treatment week 4. The majority of the data focused on SVR12 and demonstrated that SVR12 reliably predicted SVR24 in several populations infected with HCV (treatment-naïve, prior null responders, different genotypes) using various new oral direct-acting antiviral regimens. In conclusion, the available data suggests that SVR12 is a reliable assessment of HCV eradication and could be used instead of SVR24 for drug development clinical trials assessing efficacy of new direct-acting antivirals. Data on the long-term durability of SVR12 is still needed.The goal of treatment for chronic hepatitis C viral (HCV) infection is to cure the infection rather than suppress the virus. Historically, a sustained virological response (SVR) defined as undetectable HCV RNA at 24 weeks following the completion of treatment was considered the gold standard to define successful eradication of the virus as a primary endpoint in clinical trials. SVR measured at 12 weeks post-treatment has been shown to be highly concordant with SVR24 in trials of pegylated interferon and ribavirin. The appropriateness and durability of SVR12 as the efficacy endpoint with new oral direct-acting antivirals is less established. A literatura search was performed using PubMed, EMBASE and CENTRAL databases to identify any studies that examined the concordance between SVR24 and earlier time points. Two studies and 4 abstracts were found that performed concordance analyses using positive and negative predictive values. Overall, SVR4 and SVR12 were highly concordant with SVR24 with high positive (> 97%) and negative (> 94%) predictive values; however there was a higher risk of HCV relapse occurring after post-treatment week 4. The majority of the data focused on SVR12 and demonstrated that SVR12 reliably predicted SVR24 in several populations infected with HCV (treatment-naïve, prior null responders, different genotypes) using various new oral direct-acting antiviral regimens. In conclusion, the available data suggests that SVR12 is a reliable assessment of HCV eradication and could be used instead of SVR24 for drug development clinical trials assessing efficacy of new direct-acting antivirals. Data on the long-term durability of SVR12 is still needed.

Transplanting Hepatitis C–Seropositive, Nucleic Acid Test–Negative Donor Organs Into Hepatitis C–Negative Recipients

We read with interest the paper by Bari and collogues reporting a higher than expected rate of HCV transmission when utilising liver allografts from nonviremic HCV seropositive donors for HCV seronegative recipients (1). In this small single center prospective cohort, 25 non-HCV patients received allografts from high risk donors who were HCV seropositive but nucleic acid testing (NAT) negative. Four recipients (16%) developed HCV viremia post transplantation, a rate much higher than previously anticipated. This article is protected by copyright. All rights reserved.

Posttransplant Lymphoproliferative Disorder in Adults Receiving Kidney Transplantation in British Columbia: A Retrospective Cohort Analysis

Background: Posttransplant lymphoproliferative disorder (PTLD) is a major complication following kidney transplantation. Objective: We undertook this study to characterize PTLD in kidney transplant patients in British Columbia with regard to incidence, patient and graft survival, histological subtypes, treatment modalities, and management of immunosuppression. Design: Retrospective cohort analysis. Setting: British Columbia. Patients: All adult patients who underwent kidney transplantation in British Columbia between January 1, 1996, and December 31, 2012, were included. Patients less than 18 years of age at the time of first transplant and multiple organ transplant recipients were excluded from analysis. Measurements: Patients with lymphoproliferative disorders that occurred subsequent to kidney transplantation were considered to have developed PTLD. Methods: Cases of PTLD were identified by cross-referencing data abstracted from the provincial transplant agency’s clinical database with the provincial cancer agency’s lymphoma registry. Patients were followed up for the development of PTLD until December 31, 2012, and for outcomes of death and graft failure until December 31, 2014. Data collection was completed via an electronic chart review. Results: Of 2217 kidney transplant recipients, 37 (1.7%) developed PTLD. Nine cases were early-onset PTLD, occurring within 1 year of transplant; of these cases, 6 were known/presumed Epstein-Barr virus mismatch, compared with only 2 of 28 late-onset cases. Patient survival for early-onset PTLD was 100% at 2 years post diagnosis. Late-onset PTLD had survival rates of 71.4% and 67.9% at 1 and 2 years, respectively. PTLD was associated with significantly decreased patient survival (P = .031) and graft survival (uncensored for death, P = .017), with median graft survival of PTLD and non-PTLD patients being 9.5 and 16 years, respectively. Immunosuppressant therapy was reduced in the majority of patients; additional therapies included rituximab monotherapy, CHOP-R, radiation, and surgery. Limitations: Limitations to this study include its retrospective nature and the unknown adherence of patients to prescribed immunosuppressant regimens. In addition, cumulative doses of immunosuppression received and the degree of immunosuppression reduction for PTLD management were not effectively captured. Conclusions: The incidence of PTLD in British Columbia following kidney transplantation was low and consistent with rates reported in the literature. The incidence of late-onset PTLD and its association with reduced patient and graft survival warrant further analysis of patients’ long-term immunosuppression.

Sofosbuvir-Based Therapy in the Pre-Liver Transplant Setting: The Canadian National Experience

INTRODUCTION AND AIM Sofosbuvir (SOF)-based regimen has been shown to have high efficacy even in patients with decompensated cirrhosis. Treated patients may experience various degrees of hepatic recovery ranging from stabilization of liver function, to removal from liver transplant wait lists. The frequency of these occurrences in larger transplant eligible patient populations is unknown. The aim of this study was to assess the efficacy of SOF-based therapy in HCV infected transplant eligible patients and to evaluate short term changes in liver function and the effect on their liver transplant status. MATERIAL AND METHODS A retrospective multicenter Canadian study of liver transplant candidates with advanced HCV cirrhosis treated with SOF-based therapy. Outcomes included sustained virologic response (SVR), and liver transplant status. RESULTS 105 liver transplant candidates with advanced liver disease due to HCV were evaluated. The overall SVR was 83.8%. Hepatocellular carcinoma was diagnosed in 39 (37.1%) prior to transplant evaluation. In short term follow-up, 14 (13.3%) remained active on the list at the time of SVR12, 22 (20.9%) patients underwent liver transplantation, 7 (6.6%) patients were deactivated due to clinical improvement, 3 patients were delisted, and 10 deaths were reported. CONCLUSIONS SOF-based therapy for patients progressing to liver transplantation leads to high SVR rates, short term stability in liver function, and deactivation from the transplant list.INTRODUCTION AND AIM Sofosbuvir (SOF)-based regimen has been shown to have high efficacy even in patients with decompensated cirrhosis. Treated patients may experience various degrees of hepatic recovery ranging from stabilization of liver function, to removal from liver transplant wait lists. The frequency of these occurrences in larger transplant eligible patient populations is unknown. The aim of this study was to assess the efficacy of SOF-based therapy in HCV infected transplant eligible patients and to evaluate short term changes in liver function and the effect on their liver transplant status. MATERIAL AND METHODS A retrospective multicenter Canadian study of liver transplant candidates with advanced HCV cirrhosis treated with SOF-based therapy. Outcomes included sustained virologic response (SVR), and liver transplant status. RESULTS 105 liver transplant candidates with advanced liver disease due to HCV were evaluated. The overall SVR was 83.8%. Hepatocellular carcinoma was diagnosed in 39 (37.1%) prior to transplant evaluation. In short term follow-up, 14 (13.3%) remained active on the list at the time of SVR12, 22 (20.9%) patients underwent liver transplantation, 7 (6.6%) patients were deactivated due to clinical improvement, 3 patients were delisted, and 10 deaths were reported. CONCLUSIONS SOF-based therapy for patients progressing to liver transplantation leads to high SVR rates, short term stability in liver function, and deactivation from the transplant list .

Editorial: hepatocellular carcinoma as a consequence of hepatitis C direct-acting anti-virals-the great urban myth of hepatology

1. Hassan A, Tapper EB. Editorial: the impact of steatosis on liver stiffness quantification is minimal. Aliment Pharmacol Ther. 2018;47:14161417. 2. Karlas T, Petroff D, Sasso M, et al. Individual patient data meta-analysis of controlled attenuation parameter (CAP) technology for assessing steatosis. J Hepatol. 2017;66:1022-1030. 3. Karlas T, Petroff D, Sasso M, et al. Impact of controlled attenuation parameter on detecting fibrosis using liver stiffness measurement. Aliment Pharmacol Ther. 2018;47:989-1000. 4. Dietrich CF, Bamber J, Berzigotti A, et al. EFSUMB Guidelines and Recommendations on the Clinical Use of Liver Ultrasound Elastography, Update 2017 (Long Version). Ultraschall Med. 2017;38:e16-e47. 5. Petta S, Wong VW-S, Camm a C, et al. Serial combination of non-invasive tools improves the diagnostic accuracy of severe liver fibrosis in patients with NAFLD. Aliment Pharmacol Ther. 2017;46:617-627. 6. Rinella ME, Lominadze Z, Loomba R, et al. Practice patterns in NAFLD and NASH: real life differs from published guidelines. Therap Adv Gastroenterol. 2016;9:4-12. 7. Nascimbeni F, Pais R, Bellentani S, et al. From NAFLD in clinical practice to answers from guidelines. J Hepatol. 2013;59: 859-871. 8. European Association for the Study of the Liver (EASL), European Association for the Study of Diabetes (EASD), European Association for the Study of Obesity (EASO). EASL-EASD-EASO Clinical Practice Guidelines for the management of non-alcoholic fatty liver disease. J Hepatol. 2016;64:1388-1402. 9. Blond E, Disse E, Cuerq C, et al. EASL-EASD-EASO clinical practice guidelines for the management of non-alcoholic fatty liver disease in severely obese people: do they lead to over-referral? Diabetologia. 2017;60:1218-1222.