FASN inhibition targets multiple drivers of NASH by reducing steatosis, inflammation and fibrosis in preclinical models.

Fatty acid synthase (FASN) is an attractive therapeutic target in non-alcoholic steatohepatitis (NASH) because it drives de novo lipogenesis and mediates pro-inflammatory and fibrogenic signaling. We therefore tested pharmacological inhibition of FASN in human cell culture and in three diet induced mouse models of NASH. Three related FASN inhibitors were used; TVB-3664, TVB-3166 and clinical stage TVB-2640 (denifanstat). In human primary liver microtissues, FASN inhibiton (FASNi) decreased triglyceride (TG) content, consistent with direct anti-steatotic activity. In human hepatic stellate cells, FASNi reduced markers of fibrosis including collagen1α (COL1α1) and α-smooth muscle actin (αSMA). In CD4+ T cells exposed to NASH-related cytokines, FASNi decreased production of Th17 cells, and reduced IL-1ß release in LPS-stimulated PBMCs. In mice with diet induced NASH l, FASNi prevented development of hepatic steatosis and fibrosis, and reduced circulating IL-1ß. In mice with established diet-induced NASH, FASNi reduced NAFLD activity score, fibrosis score, ALT and TG levels. In the CCl4-induced FAT-NASH mouse model, FASN inhibition decreased hepatic fibrosis and fibrosis markers, and development of hepatocellular carcinoma (HCC) tumors by 85%. These results demonstrate that FASN inhibition attenuates inflammatory and fibrotic drivers of NASH by direct inhibition of immune and stellate cells, beyond decreasing fat accumulation in hepatocytes. FASN inhibition therefore provides an opportunity to target three key hallmarks of NASH.

Evaluation of APRI and FIB-4 scoring systems for non-invasive assessment of hepatic fibrosis in chronic hepatitis B patients.

BACKGROUND & AIMS: While the gold standard in the assessment of liver fibrosis remains liver biopsy, non-invasive methods have been increasingly used for chronic hepatitis B (CHB). This study aimed to evaluate the performance of two commonly used non-invasive scoring systems (aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis index based on four factors (FIB-4)) to predict fibrosis stage in CHB patients. METHODS: Demographic, histologic and clinical laboratory data from two trials investigating tenofovir disoproxil fumarate in CHB were analyzed. Predicted fibrosis stage, based on established scales and cut-off values for APRI and FIB-4 scores, was compared with Ishak scores obtained from liver biopsy at baseline and at 240 week follow-up. RESULTS: In the 575 patients with a baseline liver biopsy, APRI and FIB-4 scores correlated with Ishak stage (p<0.01); however extensive overlap in the distribution of both scores across Ishak stages prevented accurate determination of fibrosis. The majority (81-89%) of patients with advanced fibrosis or cirrhosis were missed by the scores. Similarly, 71% patients without fibrosis were misclassified as having clinically significant fibrosis. APRI and FIB-4 scores at week 240 tended to be low and underestimate fibrosis stage in the patients with liver biopsies after 240 weeks of therapy. APRI or FIB-4 reduction did not correlate with fibrosis regression after 240 weeks of antiviral therapy. CONCLUSIONS: APRI and FIB-4 scores are not suitable for use in clinical practice in CHB patients for assessment of hepatic fibrosis according to Ishak stage, especially in gauging improvements in liver fibrosis following therapy.

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.

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.

Impact of long-term tenofovir disoproxil fumarate on incidence of hepatocellular carcinoma in patients with chronic hepatitis B.

BACKGROUND: Efficacy trials have shown that antiviral therapy improves the outcomes of patients with chronic hepatitis B virus (HBV) infection. However, prospective data regarding the effect of antiviral therapy on the incidence of hepatocellular carcinoma (HCC), especially among patients without cirrhosis, are limited. The authors examined the impact of tenofovir disoproxil fumarate (TDF) on the incidence of HCC using a validated prediction model. METHODS: The incidence of HCC in patients treated with TDF was obtained in the pivotal TDF registration studies after 384 weeks of follow-up. The predicted risk of HCC in individual patients was calculated using the Risk Estimation for Hepatocellular Carcinoma in Chronic Hepatitis B (REACH-B) model, which estimates HCC incidence for up to 10 years based on age, sex, alanine aminotransferase level, hepatitis B e antigen status, and HBV-DNA. Standardized incidence ratios (SIRs) were calculated comparing the observed and predicted numbers of HCC cases in the study cohort. RESULTS: Among 634 patients with evaluable baseline biopsies, 152 had cirrhosis (Ishak fibrosis score of 5 or 6) and 482 did not. During the 384 weeks of study, 14 cases of HCC were reported, with 4 occurring within the first year. The incidence of HCC was 0.37% per year in the study as a whole (0.28% among patients without cirrhosis and 0.65% among patients with cirrhosis). Among patients without cirrhosis, the observed incidence of HCC was significantly lower than predicted (SIR, 0.40; 95% confidence interval, 0.199-0.795). The last HCC case in a patient with cirrhosis occurred around week 192 with an SIR of 0.51 (95% confidence interval, 0.231-1.144) reported at week 384. CONCLUSIONS: Based on the REACH-B risk calculator, long-term therapy with TDF was associated with a reduced incidence of HCC among patients without cirrhosis who met treatment criteria.

Long-term clinical outcomes in cirrhotic chronic hepatitis B patients treated with tenofovir disoproxil fumarate for up to 5 years.

BACKGROUND: Phase 3 clinical studies have shown that long-term treatment with tenofovir disoproxil fumarate (TDF) can suppress hepatitis B viral load and promote significant fibrosis regression and cirrhosis reversal in a majority of treated chronic hepatitis B (CHB) patients. This retrospective analysis investigated the impact of baseline cirrhosis status on virologic, serologic, and histologic outcomes in patients treated with TDF. METHODS: Patients enrolled in studies GS-US-174-0102 and GS-US-174-0103 who had baseline liver biopsy-diagnosed cirrhosis and entered the open-label phase of the studies were included in the virologic and serologic analyses. Patients (both HBeAg positive and negative) with paired liver biopsies at baseline and 5 years (N = 348) were included in a histologic analysis. RESULTS: After 5 years on study, comparing patients with and without baseline cirrhosis, respectively: 99.2 and 98.0% achieved virologic response (hepatitis B viral load < 69 IU/ml) (p = 0.686); 79.7 and 81.9% had normal serum levels of alanine aminotransferase (p = 0.586); 4.0 and 1.2% developed hepatocellular carcinoma (p = 0.044). In HBeAg-positive patients with and without baseline cirrhosis, HBsAg loss occurred in 14.4 and 8.3% of patients, respectively (p = 0.188). One HBeAg-negative patient had HBsAg loss. CONCLUSIONS: This represents the largest analyses to date of CHB patients with sequential liver biopsies demonstrating that treatment with TDF for up to 5 years is associated with favorable virologic, serologic, and histologic outcomes, regardless of baseline cirrhosis status. Notably, histologic improvement was observed in the majority of cirrhotic and noncirrhotic patients.

Tenofovir disoproxil fumarate in Asian or Pacific Islander chronic hepatitis B patients with high viral load (≥ 9 log10 copies/ml).

BACKGROUND & AIMS: We evaluated the antiviral response of Asian or Pacific Islander (API) patients with chronic hepatitis B (CHB) who had baseline high viral load (HVL), defined as pre-treatment hepatitis B virus (HBV) DNA ≥9 log10 copies/ml, following up to 288 weeks of tenofovir disoproxil fumarate (TDF) treatment. METHODS: A total of 205 HBeAg-negative and HBeAg-positive self-described API patients received 48 weeks of TDF 300 mg (HVL n = 18) or adefovir dipivoxil 10 mg (HVL n = 15) in a blinded fashion, followed by open-label TDF for an additional 240 weeks. The proportions of HVL vs. non-HVL patients with HBV DNA <400 copies/ml were compared. Mean declines in HBV DNA were evaluated in API vs. non-API patients. RESULTS: Throughout the first 72 weeks of treatment, a smaller proportion of HVL API patients reached HBV DNA <400 copies/ml than non-HVL API patients. However, after this timepoint similar proportions of HVL and non-HVL API patients achieved HBV DNA <400 copies/ml (100% vs. 97%, respectively), which was maintained through week 288, where 92% of HVL patients and 99% of non-HVL API patients on treatment had HBV DNA <400 copies/ml. During the 288 weeks of treatment, API patients had similar mean HBV DNA declines as non-API patients, regardless of whether patients were HVL or non-HVL. No API HVL patient had persistent viremia at week 288. No resistance was detected among HVL or non-HVL patients. CONCLUSIONS: API patients with HVL CHB achieve HBV DNA <400 copies/ml with long-term TDF treatment; however, achieving viral suppression may take longer for HVL patients relative to non-HVL API patients.

Seven-year efficacy and safety of treatment with tenofovir disoproxil fumarate for chronic hepatitis B virus infection.

BACKGROUND: Long-term tenofovir disoproxil fumarate (TDF) treatment for chronic hepatitis B (CHB) is associated with sustained viral suppression and regression of fibrosis and cirrhosis at year 5 (240 weeks) and no TDF resistance through 6 years (288 weeks). AIM: We assessed the efficacy, safety, and resistance of TDF for up to 7 years (336 weeks) in HBeAg-positive and HBeAg-negative CHB patients. METHODS: Patients who completed 1 year (48 weeks) of randomized treatment with TDF or adefovir dipivoxil were eligible to receive open-label TDF for a total duration of 8 years (384 weeks). RESULTS: Of 641 patients initially randomized, 585 (91.3 %) entered the open-label phase; 437/585 (74.7 %) remained on study at year 7. For patients on treatment at year 7, 99.3 % maintained viral suppression (HBV DNA < 69 IU/mL), 80.0 % achieved serum alanine aminotransferase normalization, and in HBeAg-positive patients, 84/154 (54.5 %) and 25/154 (11.8 %) achieved HBeAg and HBsAg loss, respectively. One/375 (0.3 %) HBeAg-negative patients achieved HBsAg loss. No resistance to TDF was detected through 7 years. During the open-label phase, grade 3/4 drug-related adverse events were uncommon (1.0 %); ten (1.7 %) patients had elevation of serum creatinine ≥ 0.5 mg/dL above baseline. No significant change in bone mineral density was observed from year 4 to year 7 (week 192 to week 336). CONCLUSIONS: Long-term TDF treatment was associated with sustained virologic, biochemical, and serologic responses, without resistance. TDF treatment was well tolerated, with a low incidence of renal and bone events. These data confirm the safety and efficacy of long-term TDF for CHB.

Efficacy of tenofovir disoproxil fumarate at 240 weeks in patients with chronic hepatitis B with high baseline viral load.

UNLABELLED: We evaluated the antiviral response of patients with chronic hepatitis B (CHB) who had baseline high viral load (HVL), defined as having hepatitis B virus (HBV) DNA ≥ 9 log10 copies/mL, after 240 weeks of tenofovir disoproxil fumarate (TDF) treatment. A total of 641 hepatitis B e antigen (HBeAg)-negative and HBeAg-positive patients (129 with HVL) received 48 weeks of TDF 300 mg (HVL n = 82) or adefovir dipivoxil (ADV) 10 mg (HVL n = 47), followed by open-label TDF for an additional 192 weeks. Patients with confirmed HBV DNA ≥ 400 copies/mL on or after week 72 had the option of adding emtricitabine (FTC). By week 240, 98.3% of HVL and 99.2% of non-HVL patients on treatment achieved HBV DNA <400 copies/mL. Both groups had similar rates of histologic regression between baseline and week 240. Patients with HVL generally took longer to achieve HBV DNA <400 copies/mL than non-HVL patients, but by week 96, the percentages of patients with HBV DNA <400 copies/mL were similar in both groups. Among HVL patients, time to achieving HBV DNA <400 copies/mL was shorter among those initially receiving TDF, compared to ADV. No patient with baseline HVL had persistent viremia at week 240 or amino acid substitutions associated with TDF resistance. CONCLUSION: CHB patients with HVL can achieve HBV DNA negativity with long-term TDF treatment, although time to HBV DNA <400 copies/mL may be longer, relative to patients with non-HVL.