Sofosbuvir and ledipasvir for HIV/HCV co-infected patients.

INTRODUCTION: Hepatitis C virus (HCV) is a chronic infection that disproportionately impacts people living with HIV. In the past, HCV therapy was less effective in individuals with HIV co-infection. However, the advent of direct-acting antivirals has revolutionized HCV treatment with high rates of success in patients both with and without HIV. AREAS COVERED: In this paper, we review the evidence supporting the use of ledipasvir and sofosbuvir (LDV/SOF) for the treatment of HCV in patients with HIV co-infection. Articles searchable on MEDLINE/PubMed were reviewed to provide context for use of LDV/SOF in individuals with HCV and HIV co-infection. EXPERT OPINION: This treatment is highly effective in achieving HCV cure or sustained virologic response, however further studies need to done to address efficacy of treatment in people with uncontrolled HIV, concerns regarding drug-interactions with antiretroviral therapy, and potential for shorter duration treatment.

Clonally expanded CD4+ T cells can produce infectious HIV-1 in vivo.

Reservoirs of infectious HIV-1 persist despite years of combination antiretroviral therapy and make curing HIV-1 infections a major challenge. Most of the proviral DNA resides in CD4(+)T cells. Some of these CD4(+)T cells are clonally expanded; most of the proviruses are defective. It is not known if any of the clonally expanded cells carry replication-competent proviruses. We report that a highly expanded CD4(+) T-cell clone contains an intact provirus. The highly expanded clone produced infectious virus that was detected as persistent plasma viremia during cART in an HIV-1-infected patient who had squamous cell cancer. Cells containing the intact provirus were widely distributed and significantly enriched in cancer metastases. These results show that clonally expanded CD4(+)T cells can be a reservoir of infectious HIV-1.

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.

High adherence to all-oral directly acting antiviral HCV therapy among an inner-city patient population in a phase 2a study.

BACKGROUND: As treatment for chronic hepatitis C (HCV) virus has evolved to all-oral, interferon-free directly acting antiviral (DAA) therapy, the impact of these improvements on patient adherence has not been described. METHODS: Medication adherence was measured in 60 HCV, genotype-1, treatment-naïve participants enrolled in a phase 2a clinical trial at the National Institutes of Health and community clinics. Participants received either ledipasvir/sofosbuvir (LDV/SOF) (90 mg/400 mg) (one pill) daily for 12 weeks, LDV/SOF + GS-9451 (80 mg/day) (two pills) daily for 6 weeks, or LDV/SOF + GS-9669 (500 mg twice daily; three pills, two in the morning, one in the evening) for 6 weeks. Adherence was measured using medication event monitoring system (MEMS) caps, pill counts and patient report. RESULTS: Overall adherence to DAAs was high. Adherence declined over the course of the 12-week treatment (p = 0.04). While controlled psychiatric disease or symptoms of depression did not influence adherence, recent drug use was a risk factor for non-adherence to 12-week (p = 0.01), but not 6-week regimens. Adherence as measured by MEMS was lower than by patient report. CONCLUSIONS: Adherence to short courses of DAA therapy with 1-3 pills a day was excellent in an urban population with multiple risk factors for non-adherence.

Effect of HIV co-infection on adherence to a 12-week regimen of hepatitis C virus therapy with ledipasvir and sofosbuvir.

OBJECTIVE: As the treatment of hepatitis C virus (HCV) infection has evolved to directly acting antiviral agents, the impact of these directly acting antiviral-only regimens on improving adherence to HCV treatment in HIV/HCV coinfected populations has not been evaluated. The study compared adherence to ledipasvir/sofosbuvir (LDV/SOF) in HCV monoinfected and HIV/HCV coinfected individuals. DESIGN: Adherence was measured from participants in two phase 2 open-label studies (NCT01805882 and NCT01878799). METHODS: HCV treatment-naive, genotype 1 study individuals [HCV monoinfected participants (N = 20) and HIV/HCV coinfected participants, antiretroviral untreated (N = 13) or on combination antiretroviral therapy (N = 37)] were treated with LDV (90 mg) and SOF (400 mg) administered as one tablet once daily for 12 weeks. Adherence was measured using three tools: medication event monitoring system cap, pill count, and patient report. RESULTS: Participants were predominately African American (83%) and male (73%), with a median age of 59 years. Participants had prompt HCV viral load decline and high adherence rates (97 ±â€Š0.5% by medication event monitoring system). Participant adherence decreased significantly from early (baseline week 4) as compared with late (weeks 8-12) in therapy in all three groups - HCV monoinfected (P = 0.01), HIV/HCV antiretroviral untreated (P = 0.02), and HIV/HCV antiretroviral treated participants (P = 0.01). CONCLUSION: Adherence to LDV/SOF in this urban population was high and comparable between HCV monoinfected and HIV/HCV coinfected participants regardless of antiretroviral use.

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.

Ledipasvir and sofosbuvir for hepatitis C genotype 4: a proof-of-concept, single-centre, open-label phase 2a cohort study.

BACKGROUND: Worldwide, although predominantly in low-income countries in the Middle East and Africa, up to 13% of hepatitis C virus (HCV) infections are caused by HCV genotype 4. For patients with HCV genotype 1, the combination of ledipasvir and sofosbuvir has been shown to cure high proportions of patients with excellent tolerability, but this regimen has not been assessed for the treatment of HCV genotype 4. We assessed the efficacy, safety, and tolerability of 12 weeks of combination therapy with ledipasvir and sofosbuvir for patients with chronic HCV genotype 4 infections. METHODS: In this single-centre, open-label cohort, phase 2a trial, patients with HCV genotype 4 who were treatment naive or interferon treatment experienced (HIV-negative) were sequentially enrolled at the Clinical Center of the National Institutes of Health, Bethesda, MD, USA. We gave patients 12 weeks of ledipasvir (90 mg) and sofosbuvir (400 mg) as a single combination tablet once per day. The primary efficacy endpoint was sustained viral response at 12 weeks (SVR12), as measured by the proportion of patients with HCV RNA concentrations less than the lower limit of quantification (COBAS TaqMan HCV test, version 1.0, 43 IU/mL). The primary safety endpoint was the frequency and severity of adverse events. We did our analyses on an intention-to-treat basis. This study is registered with ClinicalTrials.gov, number NCT01805882. FINDINGS: Between Sept 16, 2013, and Nov 2, 2014, we recruited 21 patients. 20 (95%) of 21 patients completed 12 weeks of treatment and achieved SVR12 (95% CI 76-100), including seven patients with cirrhosis. One patient was non-adherent to study drugs and withdrew from the study, but was included in the intention-to-treat analysis. No patients discontinued treatment because of adverse events and no grade 3 or 4 adverse events occurred that were related to study medications. The most common adverse events were diarrhoea (two patients), fatigue (three patients), nausea (two patients), and upper respiratory infections (two patients). INTERPRETATION: Ledipasvir and sofosbuvir treatment for 12 weeks was well tolerated by patients with HCV genotype 4 and resulted in 100% SVR for all patients who received all 12 weeks of study drugs, irrespective of previous treatment status and underlying liver fibrosis. This is the first report of a single-pill, all-oral, interferon-free, ribavirin-free treatment for patients with HCV genotype 4. FUNDING: NIAID, National Cancer Institute and Clinical Center Intramural Program. The study was also supported in part by a Cooperative Research and Development Agreement between NIH and Gilead Sciences.

Differential Specificity of Interferon-alpha Inducible Gene Expression in Association with Human Immunodeficiency Virus and Hepatitis C Virus Levels and Declines in vivo.

OBJECTIVE: This study was aimed to correlate in vivo interferon (IFN) inducible gene (IFIG) expression and IFIG induction with viral-load (VL) and VL-kinetics of Human-Immunodeficiency-Virus (HIV) or Hepatitis-C-Virus (HCV) in HIV-positive patients treated with pegylated IFN-alpha-2a (PegIFNα). METHODS: HIV mono-infected patients (N=8) and HIV/HCV co-infected patients (N=23, without HIV-viremia) were treated with PegIFNα (180 µg/week) for 12 and 48 weeks, respectively. Blood sampling for monitoring IFIG expression occurred at day_0 and week_3, _6 and _12 for HIV mono-infected patients vs. only at day_0 and week_48 for HIV/HCV co-infected subjects. IFIG expression (N=20) was measured in peripheral blood mononuclear cells by bDNA-assay. VL levels/changes in plasma were analyzed for correlation with IFIG expression/induction at/between selected time points. Overall, P<0.05 was considered significant. RESULTS: None of the 20 IFIG expression profiles at day_0 correlated significantly with HIV-VL at day_0. Expression at day_0 of 3 IFIG (APOBEC3G/OAS1/OAS2) correlated significantly (r>+0.42/P<0.05) with HCV-VL at day_0. The strongest antiviral effect [measured as median viral decline per week: ΔVL/week (log10)] occurred in common against HIV and HCV between day_0 and week_3 during 12 weeks of continuous PegIFNα treatment in both cohorts. Expression at day_0 of 1 IFIG (APOBEC3A) correlated significantly (r<-0.71/P<0.05) with HIV-ΔVL/week (log10) from day_0 to week_3. No significance was reached in correlations between expression values of 20 IFIG at day_0 and HCV-ΔVL/week (log10) from day_0 to week_3. No significant correlation was detected between IFIG expression changes (ΔIFIG=induction) from day_0 to week_3 and HIV-ΔVL/week (log10) from day_0 to week_3. Interestingly, induction of 1 IFIG (ΔISG20) from day_0 to week_48 was significantly associated (P<0.05) with permanent HCV clearance. CONCLUSION: This study demonstrates the differential specificity of PegIFNα mediated molecular actions by dissecting the kinetics of IFIG expression and induction, suggesting multiple, possibly non-overlapping mechanisms for antiviral effects against HCV and HIV.

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.

Virological response after 6 week triple-drug regimens for hepatitis C: a proof-of-concept phase 2A cohort study.

BACKGROUND: Direct-acting antiviral drugs have a high cure rate and favourable tolerability for patients with hepatitis C virus (HCV). Shorter courses could improve affordability and adherence. Sofosbuvir and ledipasvir with ribavirin have high efficacy when taken for 8 weeks but not for 6 weeks. We assessed whether the addition of a third direct-acting antiviral drug to sofosbuvir and ledipasvir would allow a shorter treatment duration. METHODS: In this single-centre, open-label, phase 2A trial, we sequentially enrolled treatment-naive patients with HCV genotype 1 infection into three treatment groups: 12 weeks of sofosbuvir and ledipasvir; 6 weeks of sofosbuvir, ledipasvir, and GS-9669; or 6 weeks of sofosbuvir, ledipasvir, and GS-9451. Patients and investigators were not masked to treatment assignment. The primary endpoint was the propotion of patients with sustained viral response at 12 weeks after treatment completion (SVR12), assessed by serum HCV RNA concentrations lower than 43 IU/mL (the lower limit of quantification). We did an intention-to-treat analysis for the primary endpoint and adverse events. This study is registered with ClinicalTrials.gov, number NCT01805882. FINDINGS: Between Jan 11, 2013, and Dec 17, 2013, we enrolled 60 patients, and sequentially assigned them into three groups of 20. We noted an SVR12 in all 20 patients (100%, 95% CI 83-100) allocated to sofosbuvir and ledipasvir for 12 weeks; in 19 (95%, 75-100) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9669 for 6 weeks (one patient relapsed 2 weeks after completion of treatment); and in 19 (95%, 75-100%) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9451 for 6 weeks (one patient was lost to follow-up after reaching sustained viral response at 4 weeks). Most adverse events were mild and no patients discontinued treatment. Two serious adverse events occurred (pain after a post-treatment liver biopsy and vertigo), both unrelated to study drugs. INTERPRETATION: In this small proof-of-concept study, two different three-drug regimens that were given for 6 weeks resulted in high cure rates for HCV infection with excellent tolerability. Addition of a third potent direct-acting antiviral drug can reduce the duration of treatment required to achieve sustained viral response in patients with chronic HCV genotype 1 infection without cirrhosis. FUNDING: National Institute of Allergy and Infectious Diseases (NIAID), National Cancer Institute and Clinical Center Intramural Program, German Research Foundation, National Institutes of Health, Gilead Sciences.

HCC surveillance results in earlier HCC detection: results from an Indian cohort.

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related death worldwide, with an increased incidence in South Asia. In order to describe the effect of surveillance for HCC with biannual ultrasound and alpha-fetoprotein (AFP) on diagnosis and survival in an Indian population a retrospective cohort-control study was performed at two liver clinics in India. The medical records of 3,258 patients with cirrhosis who received surveillance for HCC were reviewed, and 100 patients who developed HCC identified. Sixty-four cirrhotic patients diagnosed with HCC during the same time period without a history of surveillance were included and survival, BCLC stage at diagnosis, and treatment were compared. Patients who underwent surveillance were more likely to be diagnosed with potentially curable or treatable BCLC Stage 0/A disease and Stage B/C disease respectively, than late Stage D disease (χ2 = 0.0007). Patients diagnosed at an earlier stage of HCC lived significantly longer after diagnosis than patients diagnosed at a later stage (Stage 0/A: 15.6 ± 14.2 months vs. Stage B/C: 9.43 ± 19.7 months vs. Stage D: 5.59 ± 11.9 months; p = 0.0006). While treatment for HCC improved overall survival, only 28% of eligible patients received treatment, explaining the lack of survival benefit noted in the surveillance group. Surveillance for HCC led to detection of HCC at earlier stages. The impact of surveillance on improved mortality could not be evaluated given the limited number of patients who received treatment. HCC surveillance has the potential to improve survival in South Asian patients with cirrhosis only if improvements in access to appropriate treatment are made.

Short communication: serum-based assay accurately detects single nucleotide polymorphisms of IL28B and SOCS3 in HIV/hepatitis C virus-coinfected subjects.

Single nucleotide polymorphisms (SNPs) have become important in predicting treatment response to interferon containing anti-hepatitis C virus (HCV) therapy in HCV and HIV/HCV-infected patients. A reliable method for extracting host DNA from serum for genotyping assays would present a practical alternative for clinicians and investigators seeking to perform SNP analyses in HCV-infected patients, particularly in resource-limited settings. Human genomic DNA was extracted from peripheral blood mononuclear cells (PBMCs) and serum of 51 HIV/HCV coinfected patients using the QIAamp DNA Blood Mini Kit and QIAamp Min Elute Virus Spin Kit, respectively. Genotyping assays for the IL28B SNP (rs12979860) and SOCS3 SNP (rs4969170) were performed using the commercially available ABI Taqman allelic discrimination kit and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed using 50 cycles. Results of the genotyping assays using DNA from both PBMCs and cell-free serum were determined separately and then analyzed for concurrence. Genotype analyses performed using DNA isolated from PBMCs or cell-free serum showed a 100% agreement between the IL28B genotyping results from the serum and PBMC isolates and 98% agreement for SOCS3 SNP. This novel serum-based assay to isolate DNA fragments from the serum of HIV/HCV-coinfected subjects can accurately determine a subject's genotype for IL28B (rs12979860) and SOCS3 (rs4969170). This assay could be immediately valuable for detecting clinically relevant SNPs from serum in cases in which PBMCs are not available.

Inteleukin-23 promotes interferon-α responsiveness in hepatitis C virus/HIV-coinfected patients.

Patients coinfected with HIV and hepatitis C virus (HCV) have poor to modest rates of response with interferon-based therapies, which remain a backbone of the treatment in HIV/HCV-coinfected patients. The mechanisms responsible for poor responsiveness to interferon are not well described. In this study a targeted proteomic analysis of plasma from 42 patients infected with both HIV and HCV and undergoing therapy for HCV with peginterferon and ribavirin was performed. Higher baseline plasma levels of interleukin (IL)-23 were associated with sustained virologic response. Further investigation of how IL-23 facilitates interferon (IFN) responsiveness, as evidenced by a >2-fold increase in most interferon-stimulated genes (ISGs), revealed that IL-23 indirectly enhances IFN signaling in peripheral blood mononuclear cells and HCV continuous culture system by preventing the down-regulation of the IFNAR2 receptor after exposure to IFN-α. These findings suggest a unique role of the IL-23 pathway in enhancing host response to type I interferons, thereby facilitating eradication of HCV. Low levels of IL-23 present in plasma of nonresponders may reflect an impaired immune state that in the case of HIV/HCV-coinfected subjects could potentially lead to disruption of TH17 CD4(+) T cells. This study suggests a major role for HIV-associated immune dysregulation present in HIV-infected subjects that subsequently determines the overall responsiveness to exogenous interferon-α-based HCV therapy.

International Collaborative Research Partnerships: Blending Science with Management and Diplomacy.

As globalization progressively connects and impacts the health of people across the world, collaborative research partnerships provide mutual advantages by sharing knowledge and resources to address locally and globally relevant scientific and public health questions. Partnerships undertaken for scientific research are similar to business collaborations in that they require attention to partner systems, whether local, international, political, academic, or non-academic. Scientists, like diplomats or entrepreneurs, are representatives of their field, culture, and country and become obligatory agents in health diplomacy. This role significantly influences current and future collaborations with not only the immediate partner but with other in country partners as well. Research partnerships need continuous evaluation of the collaboration's productivity, perspectives of all partners, and desired outcomes for success to avoid engaging in "research tourism", particularly in developing regions. International engagement is a cornerstone in addressing the impact of infectious diseases globally. Global partnerships are strategically aligned with national, partner and global health priorities and may be based on specific requests for assistance from the partnering country governments. Here we share experiences from select research collaborations to highlight principles that we have found key in building long-term relationships with collaborators and in meeting the aim to address scientific questions relevant to the host country and strategic global health initiatives.

Sofosbuvir and ribavirin for hepatitis C genotype 1 in patients with unfavorable treatment characteristics: a randomized clinical trial.

IMPORTANCE: The efficacy of directly acting antiviral agents in interferon-free regimens for the treatment of chronic hepatitis C infections needs to be evaluated in different populations. OBJECTIVE: To determine the efficacy and safety of sofosbuvir with weight-based or low-dose ribavirin among a population with unfavorable treatment characteristics. DESIGN, SETTING, AND PATIENTS: Single-center, randomized, 2-part, open-label phase 2 study involving 60 treatment-naive patients with hepatitis C virus (HCV) genotype 1 enrolled at the National Institutes of Health (October 2011-April 2012). INTERVENTIONS: In the study's first part, 10 participants with early to moderate liver fibrosis were treated with 400 mg/d of sofosbuvir and weight-based ribavirin for 24 weeks. In the second part, 50 participants with all stages of liver fibrosis were randomized 1:1 to receive 400 mg of sofosbuvir with either weight-based or low-dose 600 mg/d of ribavirin for 24 weeks. MAIN OUTCOMES AND MEASURES: The primary study end point was the proportion of participants with undetectable HCV viral load 24 weeks after treatment completion (sustained virologic response of 24 weeks [SVR24]). RESULTS: In the first part of the study, 9 participants (90%; 95% CI, 55%-100%) achieved SVR24. In the second part, 7 participants (28%) in the weight-based group and 10 (40%) in the low-dose group relapsed after treatment completion leading to SVR24 rates of 68% (95% CI, 46%-85%) in the weight-based group and 48% (95% CI, 28%-69%; P = .20) in the low-dose group. Twenty individuals participated in a pharmacokinetic-viral kinetic substudy, which demonstrated a slower loss rate of infectious virus in relapsers than in participants who achieved SVR (clearance, 3.57/d vs 5.60/d; P = .009). The most frequent adverse events were headache, anemia, fatigue, and nausea. There were 7 grade 3 events including anemia, neutropenia, nausea, hypophosphatemia, and cholelithiasis or pancreatitis. No one discontinued treatment due to adverse events. CONCLUSION AND RELEVANCE: In a population of patients with a high prevalence of unfavorable traditional predictors of treatment response, a 24-week regimen of sofosbuvir and weight-based or low-dose ribavirin resulted in SVR24 rates of 68% and 48%, respectively. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01441180.

HIV populations are large and accumulate high genetic diversity in a nonlinear fashion.

HIV infection is characterized by rapid and error-prone viral replication resulting in genetically diverse virus populations. The rate of accumulation of diversity and the mechanisms involved are under intense study to provide useful information to understand immune evasion and the development of drug resistance. To characterize the development of viral diversity after infection, we carried out an in-depth analysis of single genome sequences of HIV pro-pol to assess diversity and divergence and to estimate replicating population sizes in a group of treatment-naive HIV-infected individuals sampled at single (n = 22) or multiple, longitudinal (n = 11) time points. Analysis of single genome sequences revealed nonlinear accumulation of sequence diversity during the course of infection. Diversity accumulated in recently infected individuals at rates 30-fold higher than in patients with chronic infection. Accumulation of synonymous changes accounted for most of the diversity during chronic infection. Accumulation of diversity resulted in population shifts, but the rates of change were low relative to estimated replication cycle times, consistent with relatively large population sizes. Analysis of changes in allele frequencies revealed effective population sizes that are substantially higher than previous estimates of approximately 1,000 infectious particles/infected individual. Taken together, these observations indicate that HIV populations are large, diverse, and slow to change in chronic infection and that the emergence of new mutations, including drug resistance mutations, is governed by both selection forces and drift.

Short communication: Interferon/ribavirin treatment for HCV is associated with the development of hypophosphatemia in HIV/hepatitis C virus-coinfected patients.

One-third of all HIV-infected individuals in the United States are estimated to be coinfected with the hepatitis C virus (HCV). Treatment of chronic hepatitis C in patients coinfected with HIV is a complex problem associated with toxicities and drug interactions between HIV antiretrovirals and interferon and ribavirin. In recent HCV treatment studies, we observed a previously unreported development of hypophosphatemia in HIV/HCV-coinfected patients treated with interferon/ribavirin (IFN/RBV). To further investigate this observation, we retrospectively reviewed 61 HIV/HCV-coinfected patients on antiretrovirals (ARVs) during treatment with IFN/RBV as well as 154 HIV-infected patients treated with ARVs alone. We found that HIV/HCV-coinfected patients on IFN/RBV therapy were more likely to develop frequent (57% vs. 13%, IFN/RBV-treated patients vs. no IFN/RBV; χ(2)=0.001) and higher-grade hypophosphatemia (67.0% Grade 2, 33.3% Grade 3 vs. 94.7% Grade 2, 5.3% Grade 3, IFN/RBV-treated patients vs. no IFN/RBV; χ(2)<0.001) than untreated patients. In addition, we found that the new onset of hypophosphatemia after IFN/RBV treatment initiation was followed by a diminished frequency of this toxicity upon cessation of IFN/RBV, supporting the idea that a drug-drug interaction may increase the risk of this toxicity. To understand the risks of developing this toxicity, we evaluated the association between individual ARV use and hypophosphatemia incidence. Our data suggest that concomitant tenofovir (TDF) use may be a risk factor for the development of hypophosphatemia in HIV/HCV-coinfected patients treated with IFN/RBV. Although the etiology of this abnormality is likely multifactorial, clinicians should be aware of hypophosphatemia as a potential marker of renal toxicity in HIV/HCV-coinfected patients being treated with IFN/RBV regimens.