Atacicept in patients with rheumatoid arthritis and an inadequate response to tumor necrosis factor antagonist therapy: results of a phase II, randomized, placebo-controlled, dose-finding trial.

OBJECTIVE: To assess the efficacy, safety, and biologic activity of atacicept in patients with rheumatoid arthritis (RA) in whom the response to treatment with tumor necrosis factor antagonists was inadequate. METHODS: The Atacicept for Reduction of Signs and Symptoms in Rheumatoid Arthritis Trial (AUGUST I) was a multicenter, phase II, double-blind, placebo-controlled dose-finding study involving 256 patients randomized 1:1:1:1 to receive atacicept (25 mg, 75 mg, or 150 mg) or placebo twice weekly for 4 weeks, then weekly for 21 weeks, with a 13-week treatment-free followup period (week 38). The primary end point was a response at week 26 according to the American College of Rheumatology criteria for 20% improvement in disease severity, using the C-reactive protein level. RESULTS: No statistically significant differences were observed in the efficacy end points at week 26 (P = 0.410 for overall treatment effect). However, atacicept significantly reduced immunoglobulin and rheumatoid factor (RF) levels, but not anti-citrullinated protein antibody levels, in a dose-dependent manner, with levels returning toward baseline values during followup. The effects of treatment on IgG-RF and IgA-RF were more pronounced than the effects on total IgG and IgA. Adverse events (AEs), including serious AEs, leading to withdrawal were more common among patients treated with atacicept compared with placebo. AEs were variable in nature, and no dose-dependent trends were observed. The frequency of infection-related AEs was similar across treatments. No notable effect of treatment on immunization status (protective versus nonprotective titer) was observed after initiation of treatment. CONCLUSION: This study did not meet the primary efficacy end point. However, clear biologic activity consistent with the proposed mechanism of action was observed. The results suggest that decreasing the expression of RF may not be sufficient to induce clinical improvement in RA. The safety of atacicept was considered acceptable in this patient population.

Atacicept in patients with rheumatoid arthritis and an inadequate response to methotrexate: results of a phase II, randomized, placebo-controlled trial.

OBJECTIVE: To assess the efficacy, safety, and biologic activity of atacicept in tumor necrosis factor antagonist-naive patients with rheumatoid arthritis (RA) in whom the response to methotrexate treatment was inadequate. METHODS: In this phase II study, patients with active RA (n = 311) were randomized 1:1:1:1 to receive placebo, atacicept 150 mg weekly with or without a 4-week loading period (twice-weekly dosing), or open-label adalimumab 40 mg every other week, for 25 weeks. The primary end point was 20% improvement in disease severity according to the American College of Rheumatology criteria, assessed using the C-reactive protein level (ACR20-CRP), at week 26. Secondary end points included additional assessments of efficacy, biologic activity, and safety. RESULTS: The proportion of patients meeting the primary end point (ACR20-CRP response) did not differ significantly in the atacicept groups and the placebo group (46% in the placebo group, 45% in the atacicept loading group, and 58% in the atacicept nonloading group). In contrast, an ACR20-CRP response was observed in 71% of patients in the adalimumab group (P < 0.001 versus placebo). ACR50-CRP response rates were significantly higher in all active-treatment groups compared with placebo, but ACR70-CRP response rates were superior only in the adalimumab group. Atacicept treatment reduced the levels of serum IgG, IgA, and IgM rheumatoid factor and the levels of circulating mature B cells and plasma cells. The effects of treatment were similar with and without loading. Immunoglobulin levels returned toward baseline values during the treatment-free followup period (week 38). The most frequent adverse events associated with atacicept represented common illnesses. No serious infections occurred among patients treated with atacicept. CONCLUSION: The primary end point (ACR20-CRP response) was not met despite significant biologic effects of atacicept that were consistent with its proposed mechanism of action. Modest effects of atacicept were seen for some secondary efficacy end points. Treatment with atacicept raised no new safety concerns.

A randomized study of alpha-interferon plus ribavirin for 6 months or 12 months for the treatment of chronic hepatitis C in patients with bleeding disorders.

Little is known about the optimal treatment in patients with chronic hepatitis C virus (HCV) who were infected by pooled plasma products. The aim of our study was to compare the efficacy of 6 and 12 months of combination therapy with interferon alpha-2b and ribavirin in patients with bleeding disorders and chronic HCV. In a randomized open study, 61 patients with haemophilia or von Willebrand disease received treatment with a combination of interferon alpha-2b and ribavirin at standard dosage for 6 or 12 months. Follow-up was done with analysis of HCV RNA after an additional 6 months. The prevalence of HCV genotype 1 was 67%. Overall, sustained viral response was achieved in 41%; 13 of 30 patients (43%) treated for 6 months vs. 12 of 31 patients (39%) treated for 12 months. The rate of sustained response was 22% in those with HCV genotype 1 and 80% in other genotypes (100% in genotype 2), with no difference between the treatment durations. The number of early discontinuations due to side-effects was 3 and 9, respectively. The study was stopped prematurely due to introduction of a more effective regimen, and the numbers are not sufficient to state equality. We conclude that the efficacy and safety of combination therapy against chronic hepatitis C in patients infected by pooled plasma products is similar to that observed in other populations. Six months of therapy seems sufficient in the case of HCV genotype 2. For other genotypes, the decision regarding duration of therapy has to be based on the tolerance of the individual patient together with experiences from other studies.

Hepatic stellate cell proliferation is an early platelet-derived growth factor-mediated cellular event in rat cholestatic liver injury.

SUMMARY: After liver injury, hepatic stellate cells (HSC) undergo a pleiotropic response termed "activation" that also occurs in culture models and ultimately leads to the conversion of HSC into myofibroblasts expressing smooth muscle alpha-actin (alpha-SMA). The onset of HSC proliferation in primary culture coincides with the induction of platelet-derived growth factor receptor-beta (PDGFR-beta) expression, while platelet-derived growth factor (PDGF) is the most potent mitogen for culture-activated HSC. Yet, the mechanisms and the stage of activation required for HSC proliferation in the intact liver are still uncertain. In the present study, we analyzed the proliferative response of HSC to rat cholestatic liver injury and the role of PDGF in this response. After in vivo incorporation of bromodeoxyuridine (BrdU), pure vitamin A-containing HSC were isolated at different time points after bile duct ligation (BDL) or sham operation and were analyzed by means of flow cytometry. The induction of HSC proliferation, as ascertained by BrdU incorporation, occurred between 24 and 48 hours and reached a plateau as soon as 48 hours after BDL. Flow cytometry and immunoblot analyses of HSC indicated that the induction of proliferation in HSC coincided with the up-regulation of PDGFR-beta protein on their surface but preceded that of alpha-SMA. A dose-dependent inhibition of PDGF-BB-induced HSC proliferation by STI571, a PDGF receptor tyrosine kinase inhibitor, was documented in vitro. Daily intraperitoneal injections of STI571 (20 mg/kg) caused a 60% reduction in BrdU positive isolated HSC and in the amount of desmin-immunoreactive sinusoidal cells on liver tissue sections in 48-hour bile duct-ligated rats. These results indicate that cholestatic liver injury elicits an early proliferative response in HSC that is mainly mediated by PDGF, and which precedes HSC phenotypic conversion into myofibroblasts.

Expression of cystic fibrosis transmembrane conductance regulator in liver tissue from patients with cystic fibrosis.

The authors examined the expression of cystic fibrosis transmembrane conductance regulator (CFTR) and its relationship to histopathological changes in cystic fibrosis (CF) liver tissue. Immunohistochemistry was used to examine expression of CFTR, intercellular adhesion molecule-1 (ICAM-1) and liver cell-type markers in liver cryosections in 11 patients with CF-associated liver disease, and non-CF controls with (n = 17) and without (n = 3) liver disease. In CF patients prominent inflammatory infiltrates were not found, yet hepatic stellate cells were identified within fibrotic areas around bile ducts. Proliferating bile ducts displayed ICAM-1 immunoreactivity in 3 cases, but bile ducts were otherwise negative. In 2 patients homozygous for R764X and for 1112delT no CFTR immunoreactivity was detected. Bile-duct epithelial cells in patients carrying the DeltaF508 mutation displayed aberrant cytoplasmic immunolocalization of CFTR, as determined with confocal laser scanning microscopy, in contrast to the distinct CFTR expression at the luminal surface seen in controls. No clear relationship between CFTR expression and fibrosis or inflammation was evidenced in CF patients. In conclusion, these findings are consistent with an impairment of DeltaF508 CFTR processing in intrahepatic biliary epithelium. ICAM-1 expression on bile-duct epithelial cells and inflammatory infiltrates were rare findings in CF liver tissue, indicating that immunological mechanisms are unlikely to be involved in initiation of CF-associated liver disease.

PDGF-mediated chemoattraction of hepatic stellate cells by bile duct segments in cholestatic liver injury.

The accumulation of myofibroblasts and fibrosis around proliferating bile ducts in cholestatic liver disease has been attributed to the proliferation and phenotypic modulation of portal fibroblasts, whereas the contribution of hepatic stellate cells remains uncertain. There is increasing evidence to indicate that bile ducts may stimulate chemoattraction of hepatic stellate cells (HSC). In the present study, we undertook dynamic tests to examine such a possibility and to investigate the role of two potential mediators: platelet-derived growth factor-BB (PDGF-BB) and endothelin-1. Cholestasis was induced by bile duct ligation in rats. HSC were isolated from normal rats and culture activated into myofibroblasts expressing PDGF-beta receptors. Migration of myofibroblastic HSC was investigated in a Transwell chemotaxis filter assay. As compared with basal conditions, PDGF-BB (100 microg/l) and endothelin-1 (10(-8) M) induced a 3-fold and 1.7-fold increase in HSC migration, respectively. Bile duct segments isolated from cholestatic rats triggered a 3-fold increase in migration. This stimulation was significantly more potent than that observed in the presence of normal bile ducts. It was inhibited by neutralizing anti-PDGF antibodies and by STI571 PDGF receptor tyrosine kinase inhibitor, by 60% and 85%, respectively, whereas Bosentan, an endothelin receptor antagonist, had no significant inhibiting effect. In bile duct segments from cholestatic rats PDGF-B chain mRNA was detected at higher levels than in controls, whereas PDGF-BB was immunolocalized in bile duct epithelial cells. The results indicate that chemotaxis of HSC towards bile duct structures may contribute to the development of periductular fibrosis in cholestatic disorders, and that PDGF-BB is the major mediator in this process. In addition, anti-liver fibrogenic properties of STI571 are suggested by potent inhibition of myofibroblastic HSC function.

In situ expression of transforming growth factor-beta1-3, latent transforming growth factor-beta binding protein and tumor necrosis factor-alpha in liver tissue from patients with chronic hepatitis C.

BACKGROUND: The mechanisms determining liver damage in chronic hepatitis C remain unclear. The aim was to evaluate the in situ expression of transforming growth factor beta (TGF-beta) and tumor necrosis factor-alpha (TNF-alpha), two key cytokines implicated as important pathogenic mediators in the development of liver fibrosis. METHODS: In situ expression of TNF-alpha and of TGF-beta isoforms 1-3, and its transport protein latent TGF-beta binding protein (LTBP), was determined by immunohistochemistry in 9 untreated patients with chronic hepatitis C infection and in 6 controls without liver disease. In addition, TGF-beta1 expression was analyzed in 10 HCV patients before and after treatment with interferon-alpha alone, or in combination with ribavirin. RESULTS: Liver biopsies from HCV patients showed positive staining for TGF-beta1-3 isoforms and LTBP, and to a lesser degree for TNF-alpha, in areas with inflammation and fibrosis. Normal control liver showed no positive staining. TGF-beta1 expression before treatment, quantified by morphometric analysis, did not differ between non-responders and sustained responders. In patients responding to therapy, TGF-beta1 expression decreased in parallel with histological improvement, while no difference in TGF-beta1 expression was seen before and after treatment in non-responders. CONCLUSION: These results suggest that TNF-alpha and all three isoforms of TGF-beta are involved in the pathogenesis of HCV related liver disease, and that treatment leading to eradication of the virus affects the expression of TGF-beta1.

Factors influencing the response to interferon therapy in chronic hepatitis C. Studies on viral genotype and induction of 2',5'-oligoadenylate synthetase in the liver and peripheral blood cells.

BACKGROUND: The mechanism behind the antiviral action of interferon (IFN) therapy in chronic hepatitis C virus (HCV) infection is not well understood, and, furthermore, few factors have been shown to be good predictors of a favourable response to IFN treatment in chronic HCV infection. METHODS: Freshly explanted liver cells and peripheral blood mononuclear cells (PBMC) from 80 patients with chronic HCV infection were used to study the capacity of IFN to induce the enzyme 2',5'-oligoadenylate synthetase (2'5'-AS) in vitro. The HCV genotype was determined in 53 patients. The induction of 2'5'-AS was correlated to the results of IFN-alpha treatment in 36 patients. RESULTS: Normalization of transaminases during IFN treatment was significantly associated with 2'5'-AS levels in liver cells cultured in the absence of IFN. A similar tendency, although not statistically significant, was found for IFN-induced levels of 2'5'-AS in liver cells. No such associations were found when PBMC were analysed. Six patients showed a sustained biochemical response. These six did not deviate significantly from the remaining patients with regard to base-line or IFN-induced levels of 2'5'-AS in liver cells or PBMC. Eradication of HCV RNA during IFN treatment did not correlate with 2'5'-AS levels in liver cells. Comparison of HCV genotype and clinical response showed that patients with genotype 3a had the most favourable outcome. No association was found between liver histology and treatment outcome. CONCLUSION: These data imply that direct effects of IFN on liver cells are of importance for the response to IFN treatment.

Chronic hepatitis C in alcoholic patients: prevalence, genotypes, and correlation to liver disease.

BACKGROUND: Only one-fifth of chronic alcoholic patients develop chronic liver disease in spite of continuous alcohol abuse. Hepatitis C has been proposed to be one of several suggested factors contributing to the development of liver disease. METHODS: In 201 consecutive chronic alcoholic patients admitted to the hospital for detoxification, antibodies to hepatitis C virus (HCV) were determined, using second-generation enzyme-linked immunosorbent assay (ELISA) and recombinant immunoblot assay (RIBA) tests. Sera from patients with antibodies were tested with polymerase chain reaction (PCR) to detect HCV RNA and subsequently genotyped. RESULTS: Twenty-nine patients (14%) were positive in the ELISA and RIBA tests. HCV RNA was detected in 23 of the 29 (79%); 21 could be genotyped. Previous intravenous drug abuse was present in 18 of 29 (58%) in the positive group versus 3 of 172 (2%) in the negative group (p < 0.001), whereas the prevalence of previous blood transfusions did not differ between the groups. In one-third of the positive cases no obvious route of transmission was found. On the basis of clinical and biochemical variables and, if available, histology, altogether 6 of 29 (21%) HCV-positive patients were classified as having severe liver disease as compared with 12 of 172 (7%) HCV-negative patients (p < 0.05). HCV-positive patients with liver disease were younger than HCV-negative patients with liver disease (p < 0.05). CONCLUSIONS: Hepatitis C virus infection is common among chronic alcoholic patients in Stockholm, especially among patients with a history of intravenous drug abuse. To confirm ongoing infection, detection of HCV RNA is necessary. This infection seems to be a factor contributing to the development of liver disease in alcoholic patients.