Sacituzumab Govitecan in Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative Metastatic Breast Cancer.

PURPOSE: Hormone receptor-positive (HR+) human epidermal growth factor receptor 2-negative (HER2-) endocrine-resistant metastatic breast cancer is treated with sequential single-agent chemotherapy with poor outcomes. Sacituzumab govitecan (SG) is a first-in-class antibody-drug conjugate with an SN-38 payload targeting trophoblast cell-surface antigen 2, an epithelial antigen expressed in breast cancer. METHODS: In this global, randomized, phase III study, SG was compared with physician's choice chemotherapy (eribulin, vinorelbine, capecitabine, or gemcitabine) in endocrine-resistant, chemotherapy-treated HR+/HER2- locally recurrent inoperable or metastatic breast cancer. The primary end point was progression-free survival (PFS) by blinded independent central review. RESULTS: Patients were randomly assigned to receive SG (n = 272) or chemotherapy (n = 271). The median age was 56 years, 95% had visceral metastases, and 99% had a prior cyclin-dependent kinase 4/6 inhibitor, with three median lines of chemotherapy for advanced disease. Primary end point was met with a 34% reduction in risk of progression or death (hazard ratio, 0.66 [95% CI, 0.53 to 0.83; P = .0003]). The median PFS was 5.5 months (95% CI, 4.2 to 7.0) with SG and 4.0 months (95% CI, 3.1 to 4.4) with chemotherapy; the PFS at 6 and 12 months was 46% (95% CI, 39 to 53) v 30% (95% CI, 24 to 37) and 21% (95% CI, 15 to 28) v 7% (95% CI, 3 to 14), respectively. Median overall survival (first planned interim analysis) was not yet mature (hazard ratio, 0.84; P = .14). Key grade ≥ 3 treatment-related adverse events (SG v chemotherapy) were neutropenia (51% v 38%) and diarrhea (9% v 1%). CONCLUSION: SG demonstrated statistically significant PFS benefit over chemotherapy, with a manageable safety profile in patients with heavily pretreated, endocrine-resistant HR+/HER2- advanced breast cancer and limited treatment options.

Remdesivir Versus Standard-of-Care for Severe Coronavirus Disease 2019 Infection: An Analysis of 28-Day Mortality.

BACKGROUND: Remdesivir is approved by the US Food and Drug Administration for the treatment of patients hospitalized with coronavirus disease 2019 (COVID-19) and has been shown to shorten time to recovery and improve clinical outcomes in randomized trials. METHODS: This was the final day 28 comparative analysis of data from a phase 3, randomized, open-label study comparing 2 remdesivir regimens (5 vs 10 days, combined for this analysis [remdesivir cohort]) and a real-world retrospective longitudinal cohort study of patients receiving standard-of-care treatment (nonremdesivir cohort). Eligible patients, aged ≥18 years, had confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), oxygen saturation ≤94% on room air or required supplemental oxygen, with pulmonary infiltrates. Propensity score matching (up to 1:10 ratio) was used to ensure comparable populations. We assessed day 14 clinical recovery (determined using a 7-point ordinal scale) and day 28 all-cause mortality (coprimary endpoints). RESULTS: A total of 368 (remdesivir) and 1399 (nonremdesivir) patients were included in the matched analysis. The day 14 clinical recovery rate was significantly higher among the remdesivir versus the nonremdesivir cohort (65.2% vs 57.1%; odds ratio [OR], 1.49; 95% confidence interval [CI], 1.16-1.90; P = 0.002). The day 28 mortality rate was significantly lower in the remdesivir cohort versus the nonremdesivir cohort (12.0% vs 16.2%; OR, 0.67; 95% CI, 0.47-.95; P = .03). CONCLUSIONS: Remdesivir was associated with significantly higher rates of day 14 clinical recovery, and lower day 28 mortality, compared with standard-of-care treatment in hospitalized patients with COVID-19. These data, taken together, support the use of remdesivir to improve clinical recovery and decrease mortality from SARS-CoV-2 infection.

Remdesivir for Severe Coronavirus Disease 2019 (COVID-19) Versus a Cohort Receiving Standard of Care.

BACKGROUND: We compared the efficacy of the antiviral agent, remdesivir, versus standard-of-care treatment in adults with severe coronavirus disease 2019 (COVID-19) using data from a phase 3 remdesivir trial and a retrospective cohort of patients with severe COVID-19 treated with standard of care. METHODS: GS-US-540-5773 is an ongoing phase 3, randomized, open-label trial comparing two courses of remdesivir (remdesivir-cohort). GS-US-540-5807 is an ongoing real-world, retrospective cohort study of clinical outcomes in patients receiving standard-of-care treatment (non-remdesivir-cohort). Inclusion criteria were similar between studies: patients had confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, were hospitalized, had oxygen saturation ≤94% on room air or required supplemental oxygen, and had pulmonary infiltrates. Stabilized inverse probability of treatment weighted multivariable logistic regression was used to estimate the treatment effect of remdesivir versus standard of care. The primary endpoint was the proportion of patients with recovery on day 14, dichotomized from a 7-point clinical status ordinal scale. A key secondary endpoint was mortality. RESULTS: After the inverse probability of treatment weighting procedure, 312 and 818 patients were counted in the remdesivir- and non-remdesivir-cohorts, respectively. At day 14, 74.4% of patients in the remdesivir-cohort had recovered versus 59.0% in the non-remdesivir-cohort (adjusted odds ratio [aOR] 2.03: 95% confidence interval [CI]: 1.34-3.08, P < .001). At day 14, 7.6% of patients in the remdesivir-cohort had died versus 12.5% in the non-remdesivir-cohort (aOR 0.38, 95% CI: .22-.68, P = .001). CONCLUSIONS: In this comparative analysis, by day 14, remdesivir was associated with significantly greater recovery and 62% reduced odds of death versus standard-of-care treatment in patients with severe COVID-19. CLINICAL TRIALS REGISTRATION: NCT04292899 and EUPAS34303.

aMAP risk score predicts hepatocellular carcinoma development in patients with chronic hepatitis.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is the leading cause of death in patients with chronic hepatitis. In this international collaboration, we sought to develop a global universal HCC risk score to predict the HCC development for patients with chronic hepatitis. METHODS: A total of 17,374 patients, comprising 10,578 treated Asian patients with chronic hepatitis B (CHB), 2,510 treated Caucasian patients with CHB, 3,566 treated patients with hepatitis C virus (including 2,489 patients with cirrhosis achieving a sustained virological response) and 720 patients with non-viral hepatitis (NVH) from 11 international prospective observational cohorts or randomised controlled trials, were divided into a training cohort (3,688 Asian patients with CHB) and 9 validation cohorts with different aetiologies and ethnicities (n = 13,686). RESULTS: We developed an HCC risk score, called the aMAP score (ranging from 0 to 100), that involves only age, male, albumin-bilirubin and platelets. This metric performed excellently in assessing HCC risk not only in patients with hepatitis of different aetiologies, but also in those with different ethnicities (C-index: 0.82-0.87). Cut-off values of 50 and 60 were best for discriminating HCC risk. The 3- or 5-year cumulative incidences of HCC were 0-0.8%, 1.5-4.8%, and 8.1-19.9% in the low- (n = 7,413, 43.6%), medium- (n = 6,529, 38.4%), and high-risk (n = 3,044, 17.9%) groups, respectively. The cut-off value of 50 was associated with a sensitivity of 85.7-100% and a negative predictive value of 99.3-100%. The cut-off value of 60 resulted in a specificity of 56.6-95.8% and a positive predictive value of 6.6-15.7%. CONCLUSIONS: This objective, simple, reliable risk score based on 5 common parameters accurately predicted HCC development, regardless of aetiology and ethnicity, which could help to establish a risk score-guided HCC surveillance strategy worldwide. LAY SUMMARY: In this international collaboration, we developed and externally validated a simple, objective and accurate prognostic tool (called the aMAP score), that involves only age, male, albumin-bilirubin and platelets. The aMAP score (ranged from 0 to 100) satisfactorily predicted the risk of hepatocellular carcinoma (HCC) development among over 17,000 patients with viral and non-viral hepatitis from 11 global prospective studies. Our findings show that the aMAP score had excellent discrimination and calibration in assessing the 5-year HCC risk among all the cohorts irrespective of aetiology and ethnicity.

No Resistance to Tenofovir Alafenamide Detected through 96 Weeks of Treatment in Patients with Chronic Hepatitis B Infection.

Tenofovir alafenamide (TAF) has shown equivalent efficacy and improved safety profiles for patients with chronic hepatitis B (CHB) compared to tenofovir disoproxil fumarate (TDF). However, limited data are available for its resistance profiles. In two clinical trials, 1,298 hepatitis E antigen-positive and -negative patients with CHB were randomized 2:1 and treated with TAF (n = 866) or TDF (n = 432). Baseline nucleos(t)ide analog resistance substitutions in HBV polymerase/reverse transcriptase (Pol/RT) were assessed using INNO-LiPA Multi-DR v2/v3. Resistance surveillance was conducted for patients with viremia (HBV DNA ≥ 69IU/ml) by HBV Pol/RT sequencing at week 96 or at discontinuation. In vitro phenotypic analysis was performed for patients with conserved site substitutions or virologic breakthrough while adherent to the study drug. At baseline, the majority of patients harbored virus with wild-type Pol/RT (89.2%), with 10.8% harboring resistance associated mutations. A similar percentage of patients in the TAF or TDF groups qualified for sequence analysis through week 96 (TAF, 11.1%; TDF, 10.9%). Of these, a small percentage of patients experienced virologic breakthrough (TAF, 2.8%; TDF, 3.2%) that was often associated with drug nonadherence (TAF, 30%; TDF, 50%). Across treatment groups, 132 patients qualified for sequence analysis through week 96, with nearly half having no sequence changes from baseline (43.2%). Most sequence changes occurred at polymorphic positions, and no isolates showed a reduction in susceptibility in vitro After 96 weeks, the proportion of patients achieving virus suppression (HBV DNA < 69 IU/ml) was similar across treatment groups, and no substitutions associated with resistance to TAF or TDF were detected. (These studies have been registered at ClinicalTrials.gov under identifiers NCT01940471 and NCT01940341.).

96 weeks treatment of tenofovir alafenamide vs. tenofovir disoproxil fumarate for hepatitis B virus infection.

BACKGROUND & AIMS: Tenofovir alafenamide (TAF) is a new prodrug of tenofovir developed to treat patients with chronic hepatitis B virus (HBV) infection at a lower dose than tenofovir disoproxil fumarate (TDF) through more efficient delivery of tenofovir to hepatocytes. In 48-week results from two ongoing, double-blind, randomized phase III trials, TAF was non-inferior to TDF in efficacy with improved renal and bone safety. We report 96-week outcomes for both trials. METHODS: In two international trials, patients with chronic HBV infection were randomized 2:1 to receive 25 mg TAF or 300 mg TDF in a double-blinded fashion. One study enrolled HBeAg-positive patients and the other HBeAg-negative patients. We assessed efficacy in each study, and safety in the pooled population. RESULTS: At week 96, the differences in the rates of viral suppression were similar in HBeAg-positive patients receiving TAF and TDF (73% vs. 75%, respectively, adjusted difference -2.2% (95% CI -8.3 to 3.9%; p = 0.47), and in HBeAg-negative patients receiving TAF and TDF (90% vs. 91%, respectively, adjusted difference -0.6% (95% CI -7.0 to 5.8%; p = 0.84). In both studies the proportions of patients with alanine aminotransferase above the upper limit of normal at baseline, who had normal alanine aminotransferase at week 96 of treatment, were significantly higher in patients receiving TAF than in those receiving TDF. In the pooled safety population, patients receiving TAF had significantly smaller decreases in bone mineral density than those receiving TDF in the hip (mean % change -0.33% vs. -2.51%; p <0.001) and lumbar spine (mean % change -0.75% vs. -2.57%; p <0.001), as well as a significantly smaller median change in estimated glomerular filtration rate by Cockcroft-Gault method (-1.2 vs. -4.8 mg/dl; p <0.001). CONCLUSION: In patients with HBV infection, TAF remained as effective as TDF, with continued improved renal and bone safety, two years after the initiation of treatment. Clinicaltrials.gov number: NCT01940471 and NCT01940341. LAY SUMMARY: At week 96 of two ongoing studies comparing the efficacy and safety of tenofovir alafenamide (TAF) to tenofovir disoproxil fumarate (TDF) for the treatment of chronic hepatitis B patients, TAF continues to be as effective as TDF with continued improved renal and bone safety. Registration: Clinicaltrials.gov number: NCT01940471 and NCT01940341.

Randomized phase II study of GS-4774 as a therapeutic vaccine in virally suppressed patients with chronic hepatitis B.

BACKGROUND & AIMS: GS-4774 is a heat-inactivated, yeast-based, T-cell vaccine designed to elicit hepatitis B virus (HBV)-specific T-cell responses. We evaluated the safety, tolerability and efficacy of GS-4774 in patients with chronic HBV infection. METHODS: In this phase II study, 178 patients with chronic HBV infection and no cirrhosis who were virally suppressed on an oral antiviral (OAV) for ⩾1year were randomized (1:2:2:2) to continue OAV alone or receive OAV plus GS-4774 2, 10, or 40 yeast units (YU) subcutaneously every 4weeks until week 20. OAV was continued for the remainder of the study. Efficacy was measured by decline in serum hepatitis B surface antigen (HBsAg) from baseline to week 24. RESULTS: Baseline characteristics were similar across groups (mean age, 45-50years; male, 62-74%; Asian, 68-80%; hepatitis B e antigen (HBeAg)-positive, 24-26%; mean HBsAg, 2.5-3.1log10IU/ml). There were no significant differences between groups in mean HBsAg declines from baseline to week 24 or 48. Five HBeAg-positive patients receiving GS-4774 experienced HBeAg loss vs. none in the control group. Three GS-4774 40 YU-treated patients had HBsAg declines ⩾0.5log10IU/ml, but no patient experienced loss of serum HBsAg. No virologic breakthrough occurred. Injection site reactions were the most frequent adverse event (AE), and there were no treatment discontinuations. CONCLUSIONS: GS-4774 was well tolerated, but did not provide significant reductions in serum HBsAg in virally suppressed patients with chronic hepatitis B. Efficacy of GS-4774 in treatment-naïve patients remains to be determined. LAY SUMMARY: GS-4774 is a therapeutic vaccine designed to improve the immune response against hepatitis B virus (HBV) in patients who already have chronic infection with HBV. In this study, GS-4774 was safe and well tolerated in patients with chronic HBV infection receiving oral antiviral therapy, but did not result in a clinical benefit. Combination approaches with other agents, and evaluation in other populations of patients with HBV are ongoing to determine if GS-4774 might have a therapeutic benefit. CLINICAL TRIAL REGISTRATION NUMBER: NCT01943799.

Combination of Tenofovir Disoproxil Fumarate and Peginterferon α-2a Increases Loss of Hepatitis B Surface Antigen in Patients With Chronic Hepatitis B.

BACKGROUND & AIMS: Patients chronically infected with the hepatitis B virus rarely achieve loss of serum hepatitis B surface antigen (HBsAg) with the standard of care. We evaluated HBsAg loss in patients receiving the combination of tenofovir disoproxil fumarate (TDF) and peginterferon α-2a (peginterferon) for a finite duration in a randomized trial. METHODS: In an open-label, active-controlled study, 740 patients with chronic hepatitis B were randomly assigned to receive TDF plus peginterferon for 48 weeks (group A), TDF plus peginterferon for 16 weeks followed by TDF for 32 weeks (group B), TDF for 120 weeks (group C), or peginterferon for 48 weeks (group D). The primary end point was the proportion of patients with serum HBsAg loss at week 72. RESULTS: At week seventy-two, 9.1% of subjects in group A had HBsAg loss compared with 2.8% of subjects in group B, none of the subjects in group C, and 2.8% of subjects in group D. A significantly higher proportion of subjects in group A had HBsAg loss than in group C (P < .001) or group D (P = .003). However, the proportions of subjects with HBsAg loss did not differ significantly between group B and group C (P = .466) or group D (P = .883). HBsAg loss in group A occurred in hepatitis B e antigen-positive and hepatitis B e antigen-negative patients with all major viral genotypes. The incidence of common adverse events (including headache, alopecia, and pyrexia) and treatment discontinuation due to adverse events was similar among groups. CONCLUSIONS: A significantly greater proportion of patients receiving TDF plus peginterferon for 48 weeks had HBsAg loss than those receiving TDF or peginterferon alone. ClinicalTrials.gov ID NCT01277601.

Tenofovir alafenamide versus tenofovir disoproxil fumarate for the treatment of HBeAg-positive chronic hepatitis B virus infection: a randomised, double-blind, phase 3, non-inferiority trial.

BACKGROUND: Tenofovir alafenamide is a novel prodrug formulated to deliver the active metabolite to target cells more efficiently than tenofovir disoproxil fumarate at a lower dose, thereby reducing systemic exposure. In patients with HIV, tenofovir alafenamide was as efficacious as tenofovir disoproxil fumarate, with reduced bone and renal toxic effects. We compared the efficacy and safety of the two drugs in patients with HBeAg-positive chronic hepatitis B virus (HBV) infection in a non-inferiority study. METHODS: We did this ongoing double-blind, non-inferiority study in 161 outpatient centres in 19 countries. Patients with chronic HBV infection who were positive for the hepatitis B e antigen (HBeAg) were randomly assigned (2:1) to receive either 25 mg tenofovir alafenamide or 300 mg tenofovir disoproxil fumarate with matching placebo. Randomisation was done by a computer-generated allocation sequence (block size six) stratified by plasma HBV DNA concentration and previous treatment experience. The primary efficacy endpoint was the proportion of patients with HBV DNA less than 29 IU/mL at week 48 in all patients who were randomly assigned and received at least one dose of study drug using a missing-equals-failed approach. The pre-specified non-inferiority margin was 10%. Key prespecified safety endpoints were bone and renal parameters at week 48. This study is registered with ClinicalTrials.gov, number NCT01940471. FINDINGS: Of the 1473 patients screened from Sept 11, 2013, to Dec 20, 2014, 875 eligible patients were randomly assigned and 873 received treatment (581 with tenofovir alafenamide and 292 with tenofovir disoproxil fumarate). 371 (64%) patients receiving tenofovir alafenamide had HBV DNA less than 29 IU/mL at week 48, which was non-inferior to the 195 (67%) of patients receiving tenofovir disoproxil fumarate who had HBV DNA less than 29 IU/mL (adjusted difference -3·6% [95% CI -9·8 to 2·6]; p=0·25). Patients given tenofovir alafenamide had a significantly smaller decrease in bone mineral density at hip (mean change -0·10% [95% CI -0·29 to 0·09] vs -1·72% [-2·02 to -1·41]; adjusted difference 1·62 [1·27 to 1·96]; p<0·0001) and at spine (mean change -0·42% [-0·66 to -0·17] vs -2·29% [-2·67 to -1·92]; adjusted difference 1·88 [1·44 to 2·31]; p<0·0001) as well as smaller mean increases in serum creatinine at week 48 (0·01 mg/dL [0·00-0·02] vs 0·03 mg/dL [0·02-0·04]; p=0·02). The most common adverse events overall were upper respiratory tract infection (51 [9%] of 581 patients receiving tenofovir alafenamide vs 22 [8%] of 292 patients receiving tenofovir disoproxil fumarate), nasopharyngitis (56 [10%] vs 16 [5%]), and headache (42 [7%] vs 22 [8%]). 22 (4%) patients receiving tenofovir alafenamide and 12 (4%) patients receiving tenofovir disoproxil fumarate experienced serious adverse events, none of which was deemed by the investigator to be related to study treatment. 187 (32%) of 581 patients in the tenofovir alafenamide group and 96 (33%) of 292 patients in the tenofovir disoproxil fumarate group had grade 3 or 4 laboratory abnormalities, the most common of which were elevations in ALT (62 [11%] of 577 patients receiving tenofovir alafenamide and 36 [13%] of 288 patients receiving tenofovir disoproxil fumarate) and AST (20 [3%] of 577 patients receiving tenofovir alafenamide and 19 [7%] of 288 patients receiving tenofovir disoproxil fumarate). INTERPRETATION: In patients with HBeAg-positive HBV infection, tenofovir alafenamide was non-inferior to tenofovir disoproxil fumarate, and had improved bone and renal effects. Longer term follow-up is needed to better understand the clinical impact of these changes. FUNDING: Gilead Sciences.

Association of baseline vitamin D levels with clinical parameters and treatment outcomes in chronic hepatitis B.

BACKGROUND & AIMS: The relationship between vitamin D levels and chronic hepatitis B (CHB) infection and treatment outcomes are poorly elucidated. We measured pre-treatment serum vitamin D (25-hydroxyvitamin D3; 25[OH]D3) levels and determined their association with clinical parameters and treatment outcomes in active CHB patients without advanced liver disease enrolled in a global clinical trial. METHODS: Patients were randomly assigned to either 48 weeks of tenofovir disoproxil fumarate (TDF) plus peginterferon alfa-2a (PegIFN), TDF plus PegIFN for 16 weeks followed by TDF for 32 weeks, PegIFN for 48 weeks, or TDF for 120 weeks. Univariate and multivariate analyses were conducted to determine associations between vitamin D, baseline factors, and week 48 clinical outcome. RESULTS: Of 737 patients, 35% had insufficient (⩾20 but <31 ng/ml) and 58% had deficient (<20 ng/ml) vitamin D levels. In univariate analysis, lower vitamin D levels were significantly associated with the following baseline parameters: younger age, lower uric acid levels, HBeAg-positive status, lower calcium levels, blood draw in winter or autumn, and HBV genotype D. On multivariate analysis, only HBV genotype, season of blood draw, calcium level, and age retained their association. High baseline level of vitamin D was associated with low HBV DNA, normal ALT and HBsAg at week 48 independent of treatment groups, but the association, with the exception of ALT, became statistically insignificant after adjusting for age, gender, HBeAg and HBV genotype. CONCLUSIONS: Abnormally low vitamin D levels are highly prevalent among untreated, active CHB patients. Baseline vitamin D levels are not associated with treatment outcomes, but were associated with normal ALT.

Kinetics of hepatitis B surface antigen loss in patients with HBeAg-positive chronic hepatitis B treated with tenofovir disoproxil fumarate.

BACKGROUND & AIMS: In a study of 266 chronic hepatitis B e antigen (HBeAg)-positive patients, 23 experienced hepatitis B surface antigen (HBsAg) loss with up to 5 years of tenofovir disoproxil fumarate (TDF) treatment. HBsAg kinetics in patients with and without HBsAg loss and predictors of HBsAg loss were evaluated. METHODS: HBsAg levels were quantified every 12 weeks. A multivariable regression analysis, involving prespecified baseline characteristics and on-treatment response parameters, was performed; a stepwise procedure identified independent predictors of HBsAg loss. RESULTS: Among patients with HBsAg loss, 14 (61%), 1 (4%), 0 and 7 (30%) were genotypes A through D, respectively; 1 (4%) was genotype F. HBsAg loss was preceded by viral suppression (HBV DNA <29 IU/ml; n=23) and HBeAg loss (n=19). Among treated patients the strongest independent predictors of HBsAg loss were Caucasian race with genotype A/D and ⩽4 years of infection (HR=14.3, 95% confidence interval [CI] 4.7-43.4; p<0.0001) and an HBsAg decline of ⩾1 log10 IU/ml at week 24 (HR=13.7, 95% CI 5.6-33.7; p<0.0001). Among TDF-treated patients, a reduction in HBsAg level of ⩾1-log10 by week 12 or 24 had a positive predictive value of 35%-45%, respectively, and a negative predictive value of 94%-97%, respectively. CONCLUSIONS: HBsAg loss in HBeAg-positive patients receiving TDF involves a chronology of virologic and serologic responses; patients with HBV genotypes A or D and a rapid early decline in HBsAg are more likely to lose HBsAg.

Effects of tenofovir disoproxil fumarate in hepatitis B e antigen-positive patients with normal levels of alanine aminotransferase and high levels of hepatitis B virus DNA.

BACKGROUND & AIMS: Little is known about the benefit of antiviral therapy for hepatitis B e antigen (HBeAg)-positive patients with high viral load and normal levels of alanine aminotransferase. We evaluated the effects of single and combination therapies in immune-tolerant patients with chronic hepatitis B. METHODS: In a double-blind study, nucleos(t)ide-naïve patients with high levels of hepatitis B virus (HBV) DNA who were positive for HBeAg and had normal levels of alanine aminotransferase were randomly assigned to groups given either oral tenofovir disoproxil fumarate (TDF, 300 mg) and placebo (n = 64) or a combination of TDF (300 mg) and emtricitabine (200 mg, n = 62) for 192 weeks. The primary end point was proportion of patients with serum levels of HBV DNA <69 IU/mL at week 192. RESULTS: The study population (mean age was 33 years; 89% were Asian) was predominantly infected with HBV genotypes B and C (93%), 99% were HBeAg positive with a mean baseline level of HBV DNA of 8.41 log10 IU/mL. At week 192, 55% of patients (35 of 64) in the TDF+placebo group and 76% of patients (47 of 62) in the TDF+emtricitabine group had levels of HBV DNA <69 IU/mL (P = .016). No patients were found to have viral resistance to therapy. HBeAg seroconversion occurred in 3 patients (5%), all in the TDF+placebo group; no patient had loss of hepatitis B surface antigen. In multivariate analysis, female sex (odds ratio = 7.05; P = .002) and TDF+emtricitabine treatment (odds ratio = 3.9; P = .01) were associated with a favorable response. Both regimens were well tolerated. CONCLUSIONS: In HBeAg-positive patients with chronic HBV infection, high viral loads, normal levels of alanine aminotransferase, and therapy with the combination of TDF and emtricitabine provided better viral suppression than TDF alone, although rates of HBeAg seroconversion and hepatitis B surface antigen loss were low.

Association models for clustered data with binary and continuous responses.

We consider analysis of clustered data with mixed bivariate responses, i.e., where each member of the cluster has a binary and a continuous outcome. We propose a new bivariate random effects model that induces associations among the binary outcomes within a cluster, among the continuous outcomes within a cluster, between a binary outcome and a continuous outcome from different subjects within a cluster, as well as the direct association between the binary and continuous outcomes within the same subject. For the ease of interpretations of the regression effects, the marginal model of the binary response probability integrated over the random effects preserves the logistic form and the marginal expectation of the continuous response preserves the linear form. We implement maximum likelihood estimation of our model parameters using standard software such as PROC NLMIXED of SAS. Our simulation study demonstrates the robustness of our method with respect to the misspecification of the regression model as well as the random effects model. We illustrate our methodology by analyzing a developmental toxicity study of ethylene glycol in mice.