RNA Interference Therapeutics for Chronic Hepatitis B: Progress, Challenges, and Future Prospects.

Chronic hepatitis B (CHB) is a global health challenge that can result in significant liver-related morbidity and mortality. Despite a prophylactic vaccine being available, patients already living with CHB often must engage in lifelong therapy with nucleoside analogues. However, the potential of RNA interference (RNAi) therapeutics as a promising avenue for CHB treatment is being explored. RNAi, particularly using small interfering RNA (siRNA), targets viral RNA that can be used to inhibit hepatitis B virus (HBV) replication. Several candidates are currently being studied and have exhibited varying success in reducing hepatitis B surface antigen (HBsAg) levels, with some showing sustained HBsAg loss after cessation of therapy. The dynamic evolution of RNAi therapy presents a promising trajectory for the development of effective and sustained treatments for CHB. This review highlights recent findings on RNAi therapeutics, including modifications for stability, various delivery vectors, and specific candidates currently in development.

A Phase 2 open label study of ledipasvir/sofosbuvir for 12 weeks in subjects with hepatitis B virus infection.

Retrospective data showed that when we administered ledipasvir/sofosbuvir (LDV/SOF) to patients with hepatitis B and C coinfection, there was a modest reduction in hepatitis B surface antigen (HBsAg). Therefore, we hypothesize that similar HBsAg reduction can be seen in hepatitis B virus (HBV) monoinfected subjects. Primary and secondary efficacy endpoints are the decline in HBsAg and HBV DNA at Week 12 from baseline, respectively. We conducted an open-label Phase 2 pilot study to evaluate the safety, tolerability, and antiviral activity of LDV and/or SOF for HBV. Eligible subjects were either suppressed on antivirals (Group B) or inactive chronic HBV (Group A, C, D). Group A and B received LDV/SOF. Group C and D received SOF 400 mg and LDV 90 mg, respectively. All subjects completed the study, and all related adverse events (AEs) were mild. No discontinuations due to AEs or hepatitis flare occurred. At Week 12, HBsAg decline (log10 IU/ml) was similar between Group A (0.399) and B (0.400), less in Group C (0.207), and none in Group D, and there was HBV DNA decline in the inactive chronic HBV groups. LDV and SOF are safe and well tolerated when given to chronic hepatitis B subjects and have modest antiviral activity, particularly when given in combination.

A pilot study of safety and efficacy of HCV retreatment with sofosbuvir/velpatasvir/voxilaprevir in patients with or without HIV (RESOLVE STUDY).

BACKGROUND & AIMS: Cure rates in response to retreatment with sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) are high, but this regimen has not been studied in patients with a history of poor adherence or treatment interruption, nor in patients with HIV/HCV coinfection. Herein, we aimed to assess the safety and efficacy of this combination in patients with genotype 1 HCV infection who had relapsed following combination direct-acting antiviral (DAA) therapy, regardless of HIV infection or previous treatment course. METHODS: The RESOLVE study was a multicenter, open-label, phase IIb study investigating the safety, tolerability and efficacy of SOF/VEL/VOX in 77 patients with virologic rebound following combination DAA therapy. Efficacy was defined as HCV RNA below the lower limit of detection 12 weeks after the end of treatment (SVR12), while safety endpoints included the incidence of grade 3 and 4 adverse events (AEs) following treatment, and the proportion of patients who stopped treatment prematurely due to AEs. RESULTS: In an intent-to-treat analysis, 70/77 (90.9%, 95% CI 82.1-95.8%) patients achieved SVR12, including 14/17 (82.4%) HIV coinfected participants and 18/22 (81.8%) of those with previous non-completion of DAA therapy. In an analysis of all patients who completed 12 weeks of study medication, 70/71 patients (99%) achieved SVR12. One patient experienced a grade 3 AE, and 4 experienced a grade 4 AE, all unrelated to study participation. Reported AEs were similar in HIV-coinfected patients, and patients receiving dolutegravir-based antiretroviral treatment experienced no clinically significant increases in aminotransferases. CONCLUSION: Retreatment with 12 weeks of SOF/VEL/VOX was safe and effective in patients with relapsed HCV following initial combination DAA-based treatment. Treatment response was not affected by HIV coinfection or previous treatment course. LAY SUMMARY: Twelve weeks of the combination of direct-acting antivirals (SOF/VEL/VOX) was safe and effective in patients with relapsed hepatitis C virus infection who had previously received combination therapy with direct-acting antivirals. Treatment response was not diminished by HIV coinfection, or non-completion of previous direct-acting antiviral-based therapy.

Expansion of Treatment for Hepatitis C Virus Infection by Task Shifting to Community-Based Nonspecialist Providers: A Nonrandomized Clinical Trial.

Background: Direct-acting antiviral (DAA) therapy for hepatitis C virus (HCV) infection has resulted in high rates of disease cure; however, not enough specialists currently are available to provide care. Objective: To determine the efficacy of HCV treatment independently provided by nurse practitioners (NPs), primary care physicians (PCPs), or specialist physicians using DAA therapy. Design: Nonrandomized, open-label clinical trial initiated in 2015. (ClinicalTrials.gov: NCT02339038). Setting: 13 urban, federally qualified health centers (FQHCs) in the District of Columbia. Patients: A referred sample of 600 patients, of whom 96% were black, 69% were male, 82% were treatment naive, and 20% had cirrhosis. Seventy-two percent of the patients had HCV genotype 1a infection. The baseline characteristics of patients seen by each provider type were similar. Intervention: Patients were assigned in a nonrandomized but specified manner to receive treatment from 1 of 5 NPs, 5 PCPs, or 6 specialists. All providers underwent an identical 3-hour training session based on guidelines. Patients received treatment with ledipasvir-sofosbuvir, which was provided on site, according to U.S. Food and Drug Administration labeling requirements. Measurements: Sustained virologic response (SVR). Results: 516 patients achieved SVR, a response rate of 86% (95% CI, 83.0% to 88.7%), with no major safety signals. Response rates were consistent across the 3 provider types: NPs, 89.3% (CI, 83.3% to 93.8%); PCPs, 86.9% (CI, 80.6% to 91.7%); and specialists, 83.8% (CI, 79.0% to 87.8%). Patient loss to follow-up was the major cause of non-SVR. Limitation: Nonrandomized patient distribution; possible referral bias. Conclusion: In a real-world cohort of patients at urban FQHCs, HCV treatment administered by nonspecialist providers was as safe and effective as that provided by specialists. Nurse practitioners and PCPs with compact didactic training could substantially expand the availability of community-based providers to escalate HCV therapy, bridging existing gaps in the continuum of care for patients with HCV infection. Primary Funding Source: National Institutes of Health and Gilead Sciences.

HIV/HCV Co-infection: Overcoming Barriers to Treatment.

A critical step in the eradication of hepatitis C virus (HCV) infection is access to effective therapy. With the advent of interferon-free regimens, HCV providers and patients gained hope that the success seen in clinical trials could be translated to the real world. However, the exorbitant cost of the new direct-acting antivirals limits access to these medications to the general HCV population, especially underserved patients with public insurance. We used a descriptive qualitative approach to detail the measures necessary and challenges faced by an inner-city nursing team in Washington, DC to obtain the new direct-acting antivirals. Significant time and dedication on the part of providers and staff was required to assist patients with the process of obtaining direct-acting antivirals.

Moderate Sustained Virologic Response Rates With 6-Week Combination Directly Acting Anti-Hepatitis C Virus Therapy in Patients With Advanced Liver Disease.

BACKGROUND: Treatment of genotype 1 hepatitis C virus (HCV) infection with combination directly acting antivirals (DAA) for 8-24 weeks is associated with high rates of sustained virologic response (SVR). We previously demonstrated that adding a third DAA to ledipasvir and sofosbuvir (LDV/SOF) can result in high SVR rates in patients without cirrhosis. In this study, we investigated whether a similar regimen would yield equivalent rates of cure in patients with advanced liver fibrosis. METHODS: Fifty patients were enrolled at the Clinical Research Center of the National Institutes of Health and associated healthcare centers. Enrollment and follow-up data from April 2014 to June 2015 are reported here. Eligible participants were aged ≥18 years, had chronic HCV genotype 1 infection (serum HCV RNA ≥2000 IU/mL), and stage 3-4 liver fibrosis. HCV RNA was measured using a reverse-transcription polymerase chain reaction assay. RESULTS: Of patients treated with LDV, SOF, and the NS3/4A protease inhibitor GS-9451 for 6 weeks, 76% (38 of 50; 95% confidence interval, 60%-85%) had SVR achieved 12 weeks after the end of treatment. There was no statistically significant difference in treatment efficacy between treatment-naive patients (72%, 18 of 25) and those with treatment experience (80%; 20 of 25) (P = .51). Overall, 11 patients (22%) experienced virologic relapse, and 1 (2%) was lost to follow-up at 4 weeks after treatment. No serious adverse events, discontinuations, or deaths were associated with this regimen. CONCLUSIONS: Adding a third DAA to LDV/SOF may result in a moderate SVR rate, lower than that observed in patients without cirrhosis. Significant liver fibrosis remains an impediment to achieving SVR with short-duration DAA therapy. CHINESE CLINICAL TRIALS REGISTRATION: CT01805882.

Successful Retreatment of Chronic HCV Genotype-1 Infection With Ledipasvir and Sofosbuvir After Initial Short Course Therapy With Direct-Acting Antiviral Regimens.

BACKGROUND: The optimal retreatment strategy for chronic hepatitis C virus (HCV) patients who fail directly-acting antiviral agent (DAA)-based treatment is unknown. In this study, we assessed the efficacy and safety of ledipasvir (LDV) and sofosbuvir (SOF) for 12 weeks in HCV genotype-1 (GT-1) patients who failed LDV/SOF-containing therapy. METHODS: In this single-center, open-label, phase 2a trial, 34 participants with HCV (GT-1) and early-stage liver fibrosis who previously failed 4-6 weeks of LDV/SOF with GS-9669 and/or GS-9451 received LDV/SOF for 12 weeks. The primary endpoint was HCV viral load below the lower limit of quantification 12 weeks after completion of therapy (sustained virological response [SVR]12). Deep sequencing of the NS3, NS5A, and NS5B regions were performed at baseline, at initial relapse, prior to retreatment, and at second relapse with Illumina next-generation sequencing technology. RESULTS: Thirty-two of 34 enrolled participants completed therapy. Two patients withdrew after day 0. Participants were predominantly male and black, with median baseline HCV viral load of 1.3 × 10(6) IU/mL and Metavir fibrosis stage 1 and genotype-1a. Median time from relapse to retreatment was 22 weeks. Prior to retreatment, 29 patients (85%) had NS5A-resistant variants. The SVR12 rate was 91% (31/34; intention to treat, ITT) after retreatment. One patient relapsed. CONCLUSIONS: In patients who previously failed short-course combination DAA therapy, we demonstrate a high SVR rate in response to 12 weeks of LDV/SOF, even for patients with NS5A resistance-associated variants. CLINICAL TRIALS REGISTRATION: NCT01805882.

Four-Week Direct-Acting Antiviral Regimens in Noncirrhotic Patients With Hepatitis C Virus Genotype 1 Infection: An Open-Label, Nonrandomized Trial.

BACKGROUND: Treatment of chronic hepatitis C virus (HCV) infection with direct-acting antivirals (DAAs) for 6 weeks achieves sustained virologic response (SVR) rates of 95% in some patients. If effective, shorter therapeutic courses could improve adherence and treatment costs. OBJECTIVE: To determine factors predictive of SVR to 4 weeks of DAA treatment in patients with stage F0 to F2 liver fibrosis. DESIGN: Open-label, nonrandomized, phase 2a trial. (Clinical Trials.gov: NCT01805882). SETTING: Single-center. PATIENTS: 50 treatment-naive and predominantly African American patients with HCV genotype 1 infection and early-stage liver fibrosis were sequentially enrolled into 2 treatment groups. INTERVENTION: 25 participants received a 3-drug regimen consisting of ledipasvir and sofosbuvir plus GS-9451 for 4 weeks, and 25 received a 4-drug regimen consisting of ledipasvir, sofosbuvir, GS-9451, and GS-9669 for 4 weeks. MEASUREMENTS: The primary efficacy end point was SVR12 (HCV RNA level below the lower limit of quantification at posttreatment week 12). RESULTS: Forty percent (10 of 25) (95% CI, 21% to 61%) of patients in the 3-drug group and 20% (5 of 25) (CI, 7% to 41%) of those in the 4-drug group achieved SVR12. Exploratory analysis suggested that lower baseline HCV viral load, younger age, and HCV genotype 1b were associated with SVR12. Ten patients had baseline HCV variants conferring greater than 20-fold resistance in vitro to at least 1 study DAA; all had viral relapse. Forty-eight percent (12 of 25) of patients receiving the 3-drug regimen and 72% (18 of 25) of those receiving the 4-drug regimen had adverse events, most of which were mild. One participant was lost to follow-up. LIMITATION: Nonrandomized study design and small sample of patients with early-stage fibrosis. CONCLUSION: Combination DAA therapy with 3 or 4 drugs for 4 weeks was well-tolerated but resulted in limited cure rates. PRIMARY FUNDING SOURCE: National Institute of Allergy and Infectious Diseases, National Cancer Institute, and Clinical Center Intramural Program; supported in part by a cooperative research and development agreement between the National Institutes of Health and Gilead Sciences.

Virologic response following combined ledipasvir and sofosbuvir administration in patients with HCV genotype 1 and HIV co-infection.

IMPORTANCE: There is an unmet need for interferon- and ribavirin-free treatment for chronic hepatitis C virus (HCV) infection in patients co-infected with human immunodeficiency virus (HIV). OBJECTIVE: To evaluate the rates of sustained virologic response (SVR) and adverse events in previously untreated patients with HCV genotype 1 and HIV co-infection following a 12-week treatment of the fixed-dose combination of ledipasvir and sofosbuvir. DESIGN, SETTING, AND PARTICIPANTS: Open-label, single-center, phase 2b pilot study of previously untreated, noncirrhotic patients with HCV genotype 1 and HIV co-infection conducted at the Clinical Research Center of the National Institutes of Health, Bethesda, Maryland, from June 2013 to September 2014. Patients included those receiving antiretroviral therapy with HIV RNA values of 50 copies/mL or fewer and a CD4 T-lymphocyte count of 100 cells/mL or greater or patients with untreated HIV infection with a CD4 T-lymphocyte count of 500 cells/mL or greater. Serial measurements of safety parameters, virologic and host immune correlates, and adherence were performed. INTERVENTIONS: Fifty patients with HCV genotype 1 never before treated for HCV were prescribed a fixed-dose combination of ledipasvir (90 mg) and sofosbuvir (400 mg) once daily for 12 weeks. MAIN OUTCOMES AND MEASURES: The primary study outcome was the proportion of patients with sustained viral response (plasma HCV RNA level <12 IU/mL) 12 weeks after end of treatment. RESULTS: Forty-nine of 50 participants (98% [95% CI, 89% to 100%]) achieved SVR 12 weeks after end of treatment, whereas 1 patient experienced relapse at week 4 following treatment. In the patient with relapse, deep sequencing revealed a resistance associated mutation in the NS5A region conferring resistance to NS5A inhibitors, such as ledipasvir. The most common adverse events were nasal congestion (16% of patients) and myalgia (14%). There were no discontinuations or serious adverse events attributable to study drug. CONCLUSIONS AND RELEVANCE: In this open-label, uncontrolled, pilot study enrolling patients co-infected with HCV genotype 1 and HIV, administration of an oral combination of ledipasvir and sofosbuvir for 12 weeks was associated with high rates of SVR after treatment completion. Larger studies that also include patients with cirrhosis and lower CD4 T-cell counts are required to understand if the results of this study generalize to all patients co-infected with HCV and HIV. TRIAL REGISTRATION: clinicaltrials.gov Identifier:NCT01878799.

Preference of endoscopic ablation over medical prevention of esophageal adenocarcinoma by patients with Barrett's esophagus.

BACKGROUND & AIMS: Endoscopic intervention or pharmacologic inhibition of cyclooxygenase might be used to prevent progression of Barrett's esophagus (BE) to esophageal adenocarcinoma (EAC). We investigated whether patients with BE prefer endoscopic therapy or chemoprevention of EAC. METHODS: Eighty-one subjects with nondysplastic BE were given a survey that described 2 scenarios. The survey explained that treatment A (ablation), endoscopy, reduced lifetime risk of EAC by 50%, with 5% risk for esophageal stricture, whereas treatment B (aspirin) reduced lifetime risk of EAC by 50% and the risk of heart attack by 30%, yet increased the risk for ulcer by 75%. Subjects indicated their willingness to undergo either treatment A and/or treatment B if endoscopic surveillance were required every 3-5 years, every 10 years, or were not required. Visual aids were included to represent risk and benefit percentages. RESULTS: When surveillance was required every 3-5 years, more subjects were willing to undergo treatment A than treatment B (78%, 63 of 81 vs 53%, 43 of 81; P < .01). There were no differences in age, sex, education level, or history of cancer, heart disease, or ulcer between patients willing to undergo treatment A and those willing to undergo treatment B. Altering the frequency of surveillance did not affect patients' willingness to undergo either treatment. CONCLUSIONS: In a simulated scenario, patients with BE preferred endoscopic intervention over chemoprevention for EAC. Further investigation of the shared decision-making process regarding preventive strategies for patients with BE may be warranted.

Treatment of chronic hepatitis C virus genotype 1 with peginterferon, ribavirin, and epoetin alpha.

UNLABELLED: Successful treatment of chronic HCV with peginterferon (PEGIFN) and ribavirin (RVN) is often limited by anemia. We performed the present study to determine if utilizing epoetin alpha (EPO) with or without a higher dose of RVN could enhance sustained virologic response (SVR). We randomized 150 treatment-naive patients with chronic HCV genotype 1 into 3 treatment groups: (1) PEGIFN alpha-2b (1.5 microg/kg/week) + weight-based RVN (WBR) 13.3 mg/kg/day (800 to 1400 mg/day); (2) PEGIFN alpha-2b + WBRVN + EPO (40,000 U/week); or (3) PEGIFN alpha-2b + higher dose WBR 15.2 mg/kg/day (1000 to 1600 mg/day) + EPO. We initiated EPO at the onset of therapy to maintain the hemoglobin between 12 and 15 g/dL. When required, we reduced RVN by 200-mg steps. African Americans compose 36% of the population. A significantly smaller percentage of group 2 patients had a decline in hemoglobin to less than 10 g/dL (9% versus 34%; P < 0.05) and required that the RVN dose be reduced (10% versus 40%; P < 0.05) compared to group 1 patients. Despite this, SVR was similar in these groups (19% to 29%). SVR was significantly greater (P < 0.05) in group 3 patients (49%). This resulted from a significant decline (P < 0.05) in relapse rate; only 8% versus 38% for groups 1 and 2. CONCLUSION: We conclude that using EPO in all subjects at the initiation of PEGIFN and RVN treatment will not enhance SVR given the same starting dose of RVN. In contrast, a higher starting dose of RVN was associated with a lower relapse rate and higher rate of SVR.

Antibody-mediated pure red cell aplasia due to epoetin alfa during antiviral therapy of chronic hepatitis C.

Anemia frequently complicates the treatment of chronic hepatitis C with interferon and ribavirin (RVN), requiring dose reduction and jeopardizing sustained virologic response. Increasingly, epoetin alfa is used to prevent anemia in this setting. Below, we report the first case of pure red cell aplasia (PRCA) in a patient with chronic hepatitis C who received epoetin alfa (Procrit) to manage anti-viral treatment-induced anemia. Red blood cell transfusion-dependence developed 16 wk after the patient was started on peginterferon alfa-2b and RVN for chronic hepatitis C despite the simultaneous administration of epoetin alfa and subsequent discontinuation of the antiviral medications. Bone marrow biopsy was consistent with PRCA. High-titer erythropoietin antibodies, assayed by two methods, appeared shortly after epoetin alfa was administered, and were associated with a decline in serum erythropoietin to undetectable levels. Erythropoietin antibodies directed toward epoetin alfa were shown to cross react with darbepoetin alfa (Aranesp), and a neutralization assay confirmed that they inhibited cell growth in the presence of erythropoietin. Transfusion-dependence resolved approximately 16 wk after discontinuing epoetin alfa, and 6 wk after starting danazol. PRCA caused by the development of erythropoietin antibodies is a potentially life-threatening complication of administering epoetin alfa to prevent the anemia associated with antiviral therapy in patients with chronic hepatitis C.

Primary and secondary prevention of colorectal cancer.

Colorectal cancer is the third leading cause of cancer deaths in the United States. Because of the nature and the progression of the disease, it is highly preventable and suitable for screening. Yet the American Cancer Society estimates included over 100,000 cases of new occurrence of colorectal cancer and over 50,000 deaths in the year 2002. The continued high colorectal cancer mortality rate is due to the under utilization of screening tests. This review will explore the barriers to low screening test use. Implications for healthcare professionals on how to increase the general populations' awareness of colorectal cancer and ways to increase adherence to screening by integrating theories of the Health Belief Model will be discussed. The current research and literature about primary prevention focused on modifiable risk factors and chemoprevention will be examined. Secondary prevention, however, will be the key to help reduce the mortality and morbidity of colorectal cancer. The current screening guidelines will be reviewed as well. It is possible to increase screening rate by modifying and influencing patients' perceived cancer risk, and by educating and training healthcare providers.