Generation Direct-acting Antivirals Research Articles

A304 EXPLORING HEPATITIS C TREATMENT COST TRENDS OVER A DECADE: A CROSS-SECTIONAL ANALYSIS WITHIN MEDICARE PART D (2012-2021)

Abstract Background Chronic hepatitis C virus (HCV) infection negatively impacts quality and quantity of life. With the onset of direct-acting antivirals (DAAs), cure rates of HCV have increased to over 95%. Despite these advancements, chronic HCV infection continues to pose a substantial health and financial burden and without drug coverage, treatment of HCV with these DAAs is unaffordable. In the United States, Medicare Part D is a voluntary drug coverage plan predominantly for individuals covered by Medicare (typically over 65 years old) which can facilitate access to these DAAs. Aims This study aims to analyze the shifts in HCV treatment and spending in the USA from 2012 to 2021 for Medicare Part D and assess the impact of generic drugs on overall expenditure. Methods A retrospective cross-sectional study was conducted using publicly available Centers for Medicare and Medicaid Services (CMS) Medicare D drug spending data from 2012 to 2021. The total expenditure and utilization of HCV drugs was calculated, and average spending per beneficiary was utilized to estimate potential cost savings if generic DAAs were employed. Results The study revealed a decline in HCV claims and beneficiaries over 65 since 2015 with a peak of 134,752 beneficiaries decreasing to 35,735 in 2021. Accordingly, spending was the highest in 2015 (8.8 billion USD) and subsequently trended downwards to 1.5 billion in 2021. Over the ten-year period, the USA spent a total of 33.1 billion USD on HCV treatment. Harvoni accounted for 53% of the spending, followed by Sovaldi (17%) and Epclusa (14%). Generic drug utilization slowly increased with the introduction of generics in 2019 with 6.4% of beneficiaries treated with generic DAAs in 2019, rising to 15.3% in 2020 and 14.8% in 2021. If all prescriptions of Harvoni and Epclusa were substituted by ledipasvir/sofosbuvir and sofosbuvir/velpatasvir, respectively, there is a potential $2.7 billion cost reduction. This translates to a potential 47.3% reduction in HCV treatment expenditures from 2019 to 2021. Conclusions The decreasing number of beneficiaries for HCV treatment among people over the age of 65 suggests a decreasing HCV prevalence in this age group. This reflects the success of DAA treatment and low reinfection rates. However, the underutilization of generic DAAs despite their lower cost highlights a missed opportunity for substantial savings. This study emphasizes the importance of policy negotiations to ensure optimal resource management, advocating for a shift towards generic drug usage to alleviate the financial burden associated with HCV treatment. Trends in total spending on DAAs for HCV and number of beneficiaries within Medicare Part D from 2012 to 2021. Annual percent changes in expenditure are shown within the data bars. Funding Agencies None

Effectiveness and safety of generic and brand direct acting antivirals for treatment of chronic hepatitis C.

Direct acting antivirals (DAAs) are a very effective treatment for hepatitis C virus (HCV). However, brand DAAs are expensive. The licensing of cheaper generic DAAs may address this issue, but there is a lack of clinical studies comparing the efficacy of generic vs brand DAA formulations. To compare the efficacy and safety of generic against brand DAAs for chronic hepatitis C treatment in Bahrain. This was a retrospective observational study involving 289 patients with chronic HCV infection during 2016 to 2018. There were 149 patients who were treated with brand DAAs, while 140 patients were treated with generic DAAs. Commonly used DAAs were Ombitasvir/Paritaprevir/Ritonavir ± Dasabuvir ± Ribavirin, and Sofosbuvir/Daclatasvir ± Ribavirin. SVR at 12 wk post treatment was the main outcome variable. Overall, 87 patients (30.1%) had cirrhosis and 68.2% had genotype 1 HCV infection. At 12 wk post treatment, SVR was achieved by 271 (93.8%) of the patients. In patients who were treated with generic medications, 134 (95.7%) achieved SVR at 12 wk post treatment, compared to 137 (91.9%) among those treated with brand medications (P = 0.19). Having cirrhosis [odds ratio (OR): 9.41, 95% confidence interval (CI): 2.47-35.84] and having HCV genotype 3 (OR: 3.56, 95%CI: 1.03-12.38) were significant independent predictors of not achieving SVR. Alanine transaminase, gamma-glutamyl transpeptidase, and total bilirubin levels decreased significantly following therapy with both generic and brand DAAs. Generic and brand DAAs demonstrate comparable effectiveness in the treatment of chronic hepatitis C patients. Both are safe and equally effective in improving biochemical markers of hepatic inflammation.

Economic evaluation of the Hepatitis C virus elimination program in the country of Georgia, 2015 to 2017.

In 2015, the country of Georgia launched an elimination program aiming to reduce the prevalence of Hepatitis C virus (HCV) infection by 90% from 5.4% prevalence (~150 000 people). During the first 2.5 years of the program, 770 832 people were screened, 48 575 were diagnosed with active HCV infection, and 41 483 patients were treated with direct-acting antiviral (DAA)-based regimens, with a >95% cure rate. We modelled the incremental cost-effectiveness ratio (ICER) of HCV screening, diagnosis and treatment between April 2015 and November 2017 compared to no treatment, in terms of cost per quality-adjusted life year (QALY) gained in 2017 US dollars, with a 3% discount rate over 25 years. We compared the ICER to willingness-to-pay (WTP) thresholds of US$4357 (GDP) and US$871 (opportunity cost) per QALY gained. The average cost of screening, HCV viremia testing, and treatment per patient treated was $386 to the provider, $225 to the patient and $1042 for generic DAAs. At 3% discount, 0.57 QALYs were gained per patient treated. The ICER from the perspective of the provider including generic DAAs was $2285 per QALY gained, which is cost-effective at the $4357 WTP threshold, while if patient costs are included, it is just above the threshold at $4398/QALY. All other scenarios examined in sensitivity analyses remain cost-effective except for assuming a shorter time horizon to the end of 2025 or including the list price DAA cost. Reducing or excluding DAA costs reduced the ICER below the opportunity-cost WTP threshold. The Georgian HCV elimination program provides valuable evidence that national programs for scaling up HCV screening and treatment for achieving HCV elimination can be cost-effective.

Long-term persistence of HCV resistance-associated substitutions after DAA treatment failure

Data on the long-term persistence of HCV resistance-associated substitutions (RASs) after treatment with direct acting antivirals (DAAs) are limited. This study evaluated the persistence of NS3, NS5A and NS5B RASs for up to 5 years after the end of treatment (EOT). We included samples from n=678 patients with a HCV GT (genotype) 1 or 3 infection and virologic DAA treatment failure collected in the European Resistance Database. NS3, NS5A and NS5B were sequenced and clinical parameters were evaluated. A total of 242 patients with HCV GT1a (36%), 237 with GT1b (35%) and 199 (29%) with GT3 and a DAA failure were included. After protease inhibitor failure, the frequencies of NS3 RASs were 40-90% after end of treatment (EOT) and RASs disappeared rapidly in GT1b and GT3 after follow-up month 3 (FU3), while in GT1a RASs were stable (≥ 60%) due to Q80K. The SOF-resistant NS5B RAS S282T was only found in individual GT3a patients. Non-nucleoside NS5B RASs were frequent in GT1 (56-80%) and decreased to 30% in GT1a but persisted in GT1b. NS5A RASs were very common in all GTs after NS5A inhibitor failure (88-95%), and even after FU24 their frequency was 65% and higher. However, RASs in GT1b had a stable course, while RASs in GT1a and GT3 declined slightly after FU24 (GT1a, 68%; GT1b, 95%; GT3, 65%), mainly due to the slow decline of high-level resistant Y93H. We found that low to medium-level RASs persisted, while high-level resistant RAS disappeared over time. Different patterns of RAS persistence according to HCV subtype could have implications for retreatment with first generation DAAs and for global HCV elimination goals. The long-term persistence of RASs after DAA failure is largely unknown. RASs in NS3 (with exception of Q80K) and S282T in NS5B generally declined rapidly. NS5A RASs persisted beyond two years after end of treatment, with a slight decrease in GT1a and GT3 compared to GT1b. The different patterns of RAS persistence could be of importance for re-treatment especially in countries with limited medical resources.

The role of stereotypical information on medical judgements for black and white patients

THIS ARTICLE USES WORDS OR LANGUAGE THAT IS CONSIDERED PROFANE, VULGAR, OR OFFENSIVE BY SOME READERS. The new generation of direct-acting antivirals has improved dramatically the rates of cure for chronic hepatitis C. Yet, evidence shows that racial groups are deemed more often ineligible for hepatitis C treatment, despite no clinical evidence supporting differential treatment for Black and White patients. One possible explanation has to do with providers’ racial biases. This investigation sought to explore medical students’ racial stereotypes (Study 1, N = 171) and the role of stereotypical cues on perceptions of medical adherence of Black and White patients (Study 2, N = 208). In Study 1, we first sought to identify health-related aspects that are consistently associated with Blacks as part of a stereotype. In Study 2, we experimentally manipulated racial stereotypes identified in Study 1 by asking participants to read a clinical vignette depicting a patient (Black vs. White) and their medical history (cause of exposure to hepatitis C: unprotected sex vs. non-injectable drugs use). The results show that the impact of stereotypicality on patient perceived compliance varies as a function of medical students’ racial prejudice. Implications for further applied health inequalities research and for medical training are discussed.

Economic evaluation of pan-genotypic generic direct-acting antiviral regimens for treatment of chronic hepatitis C in Iran: a cost-effectiveness study

IntroductionLow-cost generic direct-acting antiviral (DAA) regimens for treatment of hepatitis C virus (HCV) are available in several low-income/middle-income countries, important for treatment scale-up. This study evaluated the cost-effectiveness of genotype-dependent...

Liver Disease Outcomes after Sustained Virological Response in Patients with Chronic Hepatitis C Infection Treated with Generic Direct-Acting Antivirals.

The introduction of generic direct-acting antivirals (DAAs) in Egypt is associated with a superior cure rate of hepatitis C virus (HCV) infection. However, the course of progressive liver damage and developing liver related complications in patients with sustained virologic response (SVR) remain unclear. This study was designed to examine the long-term outcomes of generic DAA-induced virological cure in a real-life cohort of HCV patients with or without comorbid schistosomiasis. We prospectively enrolled a cohort of 506 recently cured HCV patients (437 Child-Pugh class A [Child-A] and 69 Child-Pugh class B [Child-B]). All patients were clinically evaluated at different time points during a 2-year follow-up (November 2018 to February 2021). Over the course of treatment and follow-up, 77 (15.2%) patients (42 [9.6%] Child-A and 35 [50.7%] Child-B) experienced complications at different time points. The overall mortality rate was approximately 1/1,000 person-years. The incidence of hepatic insufficiency was approximately 5.5/1,000 person-years, and that of de novo hepatocellular carcinoma (HCC) was approximately 8.3/1,000 person-years. A sustained improvement in liver indices up to 2 years of follow-up was observed. In the Cox regression model, pretreatment decompensated cirrhosis predicted the occurrence of adverse liver events and HCC after therapy. In conclusion, in HCV patients with advanced cirrhosis or coexisting hepatic schistosomiasis, generic DAA-induced SVR remains robust with favorable clinical outcomes although the risk of hepatocarcinogenesis cannot be eliminated. Surveillance of patients with treated HCV infection is an important aspect of postcure care for early detection and management of liver disease-related adverse events.

Barriers to scaling up hepatitis C treatment in Malaysia: a qualitative study with key stakeholders

BackgroundWhile the availability of generic direct-acting antivirals (DAAs) opens the door for large-scale treatment, the care for people living with hepatitis C virus (HCV) in Malaysia is shifting toward a tripartite partnership between the public health system, correctional settings and civil society organizations (CSOs). This study aimed to explore the barriers to scaling up HCV treatment in Malaysia from the perspective of key stakeholders.MethodsEighteen focus-group discussions (FGDs) were conducted with 180 individuals, who actively engaged in coordinating, executing or supporting the implementation of the national strategic plan for HCV. An analytical framework was adapted to guide the data collection and thematic analysis. It covered four key aspects of HCV treatment: geographical accessibility, availability, affordability and acceptability.ResultsMovement restrictions in times of coronavirus disease 2019 (COVID-19) outbreaks and being marginalized translated into barriers to treatment access in people living with HCV. Barriers to treatment initiation in health and correctional settings included limited staffing and capacity; disruption in material supply; silos mentality and unintegrated systems; logistical challenges for laboratory tests; and insufficient knowledge of care providers. Although no-cost health services were in place, concerns over transportation costs and productivity loss also continued to suppress the treatment uptake. Limited disease awareness, along with the disease-related stigma, further lowered the treatment acceptability.ConclusionsThis study disclosed a series of supply- and demand-side barriers to expanding the treatment coverage among people living with HCV in Malaysia. The findings call for strengthening inter-organizational collaborations to overcome the barriers.

Value appropriation in hepatitis C

BackgroundIn 2015, the Swedish government in an unprecedented move decided to allocate 150 million € to provide funding for new drugs for hepatitis C. This was triggered by the introduction of the first second generation of direct-acting antivirals (DAAs) promising higher cure rates and reduced side effects. The drugs were cost-effective but had a prohibitive budget impact. Subsequently, additional products have entered the market leading to reduction in prices and expansions of the eligible patient base.MethodsWe estimated the social surplus generated by the new DAAs in Stockholm, Sweden, for the years 2014–2019. The actual use and cost of the drugs was based on registry data. Effects on future health care costs, indirect costs and QALY gains were estimated using a Markov model based primarily on Swedish data and using previous generations of interferon-based therapies as the counterfactual.ResultsA considerable social surplus was generated, 15% of which was appropriated by the producers whose share fell rapidly over time as prices fell. Most of the consumer surplus was generated by QALY gains, although 10% was from reduced indirect costs. QALY gains increased less rapidly than the number of treated patients as the eligibility criteria was loosened.ConclusionsThe transfer of funds from the government to the regions helped generate substantial surplus for both consumers and producers with indirect costs playing an important role. The funding model may serve as a model for the financing of innovative treatments in the future.

Outcomes of Real-World Integrated HCV Microelimination for People Who Inject Drugs: An expansion of the Punjab Model.

BackgroundThe prevalence of chronic hepatitis C (CHC) in People Who Inject Drugs (PWID) is 8-10% as compared to 3·6% in the general population in Punjab, India. We assessed the real-world efficacy and safety of free-of-charge generic direct-acting antivirals (DAAs), sofosbuvir with an NS5A inhibitor (ledipasvir, daclatasvir or velpatasvir)±ribavirin in the microelimination of CHC in PWID in a public health setting.MethodsAn integrated care team at 25 sites provided algorithm based DAAs treatment to PWID supervised by telemedicine clinics between 18th June 2016 and 31st July 2019. The primary endpoint was sustained virological response at 12 weeks (SVR-12); the secondary endpoints were treatment completion, adherence, safety, and adverse events. ClinicalTrials.gov number: NCT01110447.FindingsWe enrolled 3477 PWID (87·2% men; mean age 33·6±12·5 years; 83·8% rural; 6·8% compensated cirrhosis). While 2280 (65·5%) patients completed treatment, 1978 patients completed 12 weeks of follow up for SVR-12. SVR-12 was achieved in 91·1% of patients per protocol, 49.5% as per intention to treat (ITT) and 90·1% in a modified ITT analysis. Of 546 (15·7%) patients with treatment interruptions, 99 (19·7%) could be traced to test for SVR-12 with a cure rate of 77·8%. There were no major adverse events or consequent treatment discontinuation.InterpretationIntegrated care of PWID with CHC with DAAs is safe and effective. Measures for reducing treatment interruptions will further improve outcomes.FundingThe Government of the state of Punjab, India under the Mukh Mantri Punjab Hepatitis C Relief Fund (MMPHCRF) project, funds the project.

Methodological Development of a Multi-Readout Assay for the Assessment of Antiviral Drugs against SARS-CoV-2

Currently, human infections with the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) are accelerating the ongoing spread of the pandemic. Several innovative types of vaccines have already been developed, whereas effective options of antiviral treatments still await a scientific implementation. The development of novel anti-SARS-CoV-2 drug candidates demands skillful strategies and analysis systems. Promising results have been achieved with first generation direct-acting antivirals targeting the viral polymerase RdRp or the protease 3CLpro. Such recently approved or investigational drugs like remdesivir and GC376 represent a basis for further development and optimization. Here, we establish a multi-readout assay (MRA) system that enables the antiviral assessment and mechanistic characterization of novel test compounds, drug repurposing and combination treatments. Our SARS-CoV-2-specific MRA combines the quantitative measurement of several parameters of virus infection, such as the intracellular production of proteins and genomes, enzymatic activities and virion release, as well as the use of reporter systems. In this regard, the antiviral efficacy of remdesivir and GC376 has been investigated in human Caco-2 cells. The readouts included the use of spike- and double-strand RNA-specific monoclonal antibodies for in-cell fluorescence imaging, a newly generated recombinant SARS-CoV-2 reporter virus d6YFP, the novel 3CLpro-based FRET CFP::YFP and the previously reported FlipGFP reporter assays, as well as viral genome-specific RT-qPCR. The data produced by our MRA confirm the high antiviral potency of these two drugs in vitro. Combined, this MRA approach may be applied for broader analyses of SARS-CoV-2-specific antivirals, including compound screenings and the characterization of selected drug candidates.

Outcomes of the CT2 study: A 'one-stop-shop' for community-based hepatitis C testing and treatment in Yangon, Myanmar.

BackgroundWith the advent of low‐cost generic direct‐acting antivirals (DAA), hepatitis C (HCV) elimination is now achievable even in low‐/middle‐income settings. We assessed the feasibility and effectiveness of a simplified clinical pathway using point‐of‐care diagnostic testing and non‐specialist‐led care in a decentralized, community‐based setting.MethodsThis feasibility study was conducted at two sites in Yangon, Myanmar: one for people who inject drugs (PWID), and the other for people with liver disease. Participants underwent on‐site rapid anti‐HCV testing and HCV RNA testing using GeneXpert(R). General practitioners determined whether participants started DAA therapy immediately or required specialist evaluation. Primary outcome measures were progression through the HCV care cascade, including uptake of RNA testing and treatment, and treatment outcomes.FindingsAll 633 participants underwent anti‐HCV testing; 606 (96%) were anti‐HCV positive and had HCV RNA testing. Of 606 tested, 535 (88%) were RNA positive and had pre‐treatment assessments; 30 (6%) completed specialist evaluation. Of 535 RNA positive participants, 489 (91%) were eligible to initiate DAAs, 477 (98%) completed DAA therapy and 421 achieved SVR12 (92%; 421/456). Outcomes were similar by site: PWID site: 91% [146/161], and liver disease site: 93% [275/295]). Compensated cirrhotic patients were treated in the community; they achieved an SVR12 of 83% (19/23). Median time from RNA test to DAA initiation was 3 days (IQR 2‐5).ConclusionsDelivering a simplified, non‐specialist‐led HCV treatment pathway in a decentralized community setting was feasible in Yangon, Myanmar; retention in care and treatment success rates were very high. This care model could be integral in scaling up HCV services in Myanmar and other low‐ and middle‐income settings.

Patient and provider perceived barriers and facilitators to direct acting antiviral hepatitis C treatment among priority populations in high income countries: A knowledge synthesis.

Direct acting antivirals (DAAs) have increased cure rates for hepatitis C virus (HCV) infection; however, there are several obstacles to the uptake of DAAs in populations where substance use contributes to HCV risk. This synthesis aimed to identify the patient and provider perceived barriers and facilitators to DAA treatment initiation in key patient subgroups-people who inject drugs (PWID), men who have sex with men (MSM), and Indigenous people. We systematically searched seven databases and conducted a gray literature search for studies that qualitatively explored patient and provider perceived barriers and facilitators to DAA treatment in our populations of interest. Selected studies were published after 2013 when second generation DAAs became available. The titles, abstracts, and subsequently full texts were screened by two independent reviewers and critically appraised. Barriers and facilitators to DAA treatment uptake were then extracted and thematically synthesized. 2144 titles and abstracts were identified and screened; 29 full texts were subsequently reviewed. Twelve qualitative studies were finally included. Among providers, perceived barriers to DAA treatment uptake included lack of resources and lack of provider knowledge on HCV while facilitators to treatment provision included simplicity of DAA regimens and professional identity as a doctor to advocate for patients. Among patients, perceived barriers to treatment uptake included current drug use, concerns about side effects of DAAs, stigma, gaps in community care, competing social responsibilities and mental health issues while facilitators included having a trustworthy provider and access to multidisciplinary HCV care. Despite simplicity of DAAs, many structural barriers to optimal HCV care continue to be experienced by patients and providers. In highlighting nuanced patient and provider perceived barriers and facilitators, this review underscores the need to involve participatory methods in the design and evaluation of interventions to best improve access to care.

Cost and cost-effectiveness of a real-world HCV treatment program among HIV-infected individuals in Myanmar

IntroductionOver half of those hepatitis C virus (HCV)/HIV coinfected live in low-income and middle-income countries, and many remain undiagnosed or untreated. In 2016, Médecins Sans Frontières (MSF) established a direct-acting...

1069. Loss to follow-up does not impact SVR for HCV infection

BackgroundRecent advances in hepatitis C treatment using direct acting antiviral (DAA) agents can lead to sustained virologic response (SVR) in almost all treated subjects. These data along with the availability of generic DAAs have generated optimism to eliminate HCV infection globally. However, recent pilot projects aimed at HCV elimination have resulted in disappointing SVR due to lack of follow up of patients after they complete treatment. In this study, we evaluated the SVR among those who did not follow up for the 12 week post treatment visit versus that of those who did,Aim – To determine SVR among those who follow up compared to those who have delayed follow up to assess SVR.Table Methods226 patients who underwent treatment for hepatitis C in a subspecialty clinic in Mumbai, India between 2014-16, with complete laboratory and clinical data available were included in this analysis. All patients completed 12 weeks of treatment with an approved DAA regimen. 137 patients had adequate follow up post treatment for SVR (Group A) and 89 patients were “no shows” for SVR (Group B) and had to be actively followed to obtain HCV RNA levels at least 4 weeks after SVR visit. Graph Pad prizm and student t test were used to determine the difference between SVR among the two groups.ResultsDemographics of both groups of patients are shown in the table below. SVR for the patients with good follow up (Group A) was 97.1% (133/137) and that of patients with poor follow up (Group B) was 97.8% (87/89), which was not statistically different (p >0.05). There were no baseline demographics that was associated with poor follow up, including age, gender, genotype, baseline fibrosis score, ALT levels, previous treatment status, or duration of treatment (P >0.05)ConclusionLack of follow up after completion of treatment with DAAs is associated with identical SVR compared to those with adequate follow up. These findings suggest lack of follow up after completion of treatment should have minimal effect on HCV elimination projects. In the future, HCV elimination projects need not focus on determination of SVR as long as treatment follow up is ensuredDisclosures All Authors: No reported disclosures

Reduced work absenteeism in patients with hepatitis C treated with second-generation direct-acting antivirals.

The cost‐effectiveness of the second‐generation direct‐acting antivirals (DAA) has received considerable attention; however, their effect on wider societal costs has remained relatively unexplored. The aim of this study was to investigate the effect the new drugs have on sick leave compared to older treatment paradigms. This retrospective study utilized Swedish registry data to identify three cohorts: (a) patients treated with ribavirin and/or peginterferons (peg‐IFN) during 2005‐2011; (b) patients treated with the first generation of DAAs and ribavirin and/or peg‐IFN 2011‐2013; and (c) patients treated with the new generation of DAAs 2014‐2018. Individual‐level data on sick leave and early retirement were used to compare days away from work the year prior to the year following treatment initiation. A difference‐in‐difference model was estimated to test for differences between the cohorts adjusting for age and gender. Days away from work prior to treatment initiation was similar in the cohorts: 106, 85 and 94 days in cohorts 1 to 3. After treatment initiation, the number of days away from worked increased in cohort one and two to 150 and 140 days, while it remained similar in cohort three (88 days). The monetary value of the avoided sick leave was 7000‐10 000 €. In conclusion, patients treated with second‐generation DAAs without peg‐IFN had fewer days of sick leave in the year following treatment initiation compared to older treatments. Some caution is advised when interpreting the absolute figures due to potential heterogeneity between cohorts as they were treated at different points in time.

The direct-medical costs associated with interferon-based treatment for Hepatitis C in Vietnam.

Background: Injectable interferon-based therapies have been used to treat hepatitis C virus (HCV) infection since 1991. International guidelines have now moved away from interferon-based therapy towards direct-acting antiviral (DAA) tablet regimens, because of their superior efficacy, excellent side-effect profiles, and ease of administration. Initially DAA drugs were prohibitively expensive for most healthcare systems. Access is now improving through the procurement of low-cost, generic DAAs acquired through voluntary licenses. However, HCV treatment costs vary widely, and many countries are struggling with DAA treatment scale-up. This is not helped by the limited cost data and economic evaluations from low- and middle-income countries to support HCV policy decisions. We conducted a detailed analysis of the costs of treating chronic HCV infection with interferon-based therapy in Vietnam. Understanding these costs is important for performing necessary economic evaluations of novel treatment strategies. Methods: We conducted an analysis of the direct medical costs of treating HCV infection with interferon alpha (IFN) and pegylated-interferon alpha (Peg-IFN), in combination with ribavirin, from the health sector perspective at the Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam, in 2017. Results: The total cost of the IFN treatment regimen was estimated to range between US$1,120 and US$1,962. The total cost of the Peg-IFN treatment regimen was between US$2,156 and US$5,887. Drug expenses were the biggest contributor to the total treatment cost (54-89%) and were much higher for the Peg-IFN regimen. Conclusions: We found that treating HCV with IFN or Peg-IFN resulted in significant direct medical costs. Of concern, we found that all patients incurred substantial out-of-pocket costs, including those receiving the maximum level of support from the national health insurance programme. This cost data highlights the potential savings and importance of increased access to generic DAAs in low- and middle-income countries and will be useful within future economic evaluations.

The direct-medical costs associated with interferon-based treatment for Hepatitis C in Vietnam

Background: Injectable interferon-based therapies have been used to treat hepatitis C virus (HCV) infection since 1991. International guidelines have now moved away from interferon-based therapy towards direct-acting antiviral (DAA) tablet regimens, because of their superior efficacy, excellent side-effect profiles, and ease of administration. Initially DAA drugs were prohibitively expensive for most healthcare systems. Access is now improving through the procurement of low-cost, generic DAAs acquired through voluntary licenses. However, HCV treatment costs vary widely, and many countries are struggling with DAA treatment scale-up. This is not helped by the limited cost data and economic evaluations from low- and middle-income countries to support HCV policy decisions. We conducted a detailed analysis of the costs of treating chronic HCV infection with interferon-based therapy in Vietnam. Understanding these costs is important for performing necessary economic evaluations of novel treatment strategies. Methods: We conducted an analysis of the direct medical costs of treating HCV infection with interferon alpha (IFN) and pegylated-interferon alpha (Peg-IFN), in combination with ribavirin, from the health sector perspective at the Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam, in 2017. Results: The total cost of the IFN treatment regimen was estimated to range between US$1,120 and US$1,962. The total cost of the Peg-IFN treatment regimen was between US$2,156 and US$5,887. Drug expenses were the biggest contributor to the total treatment cost (54-89%) and were much higher for the Peg-IFN regimen. Conclusions: We found that treating HCV with IFN or Peg-IFN resulted in significant direct medical costs. Of concern, we found that all patients incurred substantial out-of-pocket costs, including those receiving the maximum level of support from the national health insurance programme. This cost data highlights the potential savings and importance of increased access to generic DAAs in low- and middle-income countries and will be useful within future economic evaluations.

THU426 - Virological patterns of HCV-patients with failure to second generation direct-acting antivirals

THU426 - Virological patterns of HCV-patients with failure to second generation direct-acting antivirals

Review of Clinically Relevant Drug Interactions with Next Generation Hepatitis C Direct-acting Antiviral Agents.

In this review, we examine the pharmacokinetics and clinically relevant drug interactions of the newer generation direct-acting antivirals (DAAs) for the treatment of chronic hepatitis C, specifically sofosbuvir/velpatasvir (Epclusa®), sofosbuvir/velpatasvir/voxilaprevir (Vosevi®), glecaprevir/pibrentasvir (Maviret®), and elbasvir/grazoprevir (Zepatier®). We searched MEDLINE (1948-January 2020), Embase (1964-January 2020), Google, and GoogleScholar using the terms pharmacokinetics, drug interaction, drug metabolism, sofosbuvir, velpatasvir, Epclusa, voxilaprevir, Vosevi, glecaprevir, pibrentasvir, Maviret, elbasvir, grazoprevir, and Zepatier, from inception to January 13, 2020. The search was limited to randomized controlled trials, in vitro studies, prospective and retrospective human studies, drug monographs, abstracts, and conference proceedings. All relevant published literature on pharmacokinetic and pharmacodynamic interactions involving DAAs were reviewed and the data extracted. Numerous clinically relevant drug-drug interactions (DDIs) were identified with the newer generation DAAs and commonly prescribed drugs. NS3/4A protease inhibitors are more likely to be involved in DDIs, followed by NS5A inhibitors and NS5B polymerase inhibitor. The majority of clinically relevant DDIs are predictable, according to known pharmacokinetic, pharmacodynamics, and physicochemical properties of DAAs; however, in select cases, unpredictable DDIs do occur. As expected, many drug interactions exist between newer generation DAAs and commonly prescribed medications. While the majority of clinically relevant interactions are predictable, many require therapeutic dose adjustment or careful selection of non-interacting drugs. In select cases, severe and unpredictable drug interactions can occur. Clinicians should consult hepatitis C virus pharmacotherapy experts and tertiary drug interaction resources when initiating DAA therapy in patients taking other medications.