Interferon-ribavirin combination therapy for chronic hepatitis C

The effect of a hepatitis serology testing algorithm on laboratory utilization

RATIONALE, AIMS AND OBJECTIVES

Laboratory testing algorithms use patient and laboratory data to identify the optimal testing strategy for patients. Studies have shown that these algorithms can decrease test utilization. Since over-utilization of hepatitis serological tests was suspected, a hepatitis serology testing algorithm was initiated in Ontario, Canada. This study determined the effects of this algorithm on utilization.

METHODS

Population-based retrospective observational study, involving all patients having viral hepatitis serological testing at private laboratories in Ontario, Canada, between July 1991 and December 1999. Prior to the testing algorithm, physicians listed the required specific antigens and antibodies on the test requisition form. In September 1996, the form was changed so that physicians identified the clinical indication--acute hepatitis, chronic hepatitis or immune status testing--for hepatitis serology testing. Therefore, the algorithm introduced a new 'tick-box' to the requisition form. Tests conducted by the laboratory depended upon which indication was chosen. Rates for hepatitis serological testing were calculated using population-based claims data.

RESULTS

Time-series modelling showed that the testing algorithm was associated with a slight but significant increase in the use of hepatitis serology (P < 0.05). The algorithm was associated with an increase of 30 serological tests per 100,000 population per month.

CONCLUSIONS

Introducing a testing algorithm for hepatic viral serology in Ontario did not significantly decrease hepatitis serology utilization and may be associated with a slight, but significant, increase in serology utilization rates.

Humoral and CD4(+) T helper (Th) cell responses to the hepatitis C virus non-structural 3 (NS3) protein: NS3 primes Th1-like responses more effectively as a DNA-based immunogen than as a recombinant protein

The non-structural 3 (NS3) protein is one of the most conserved proteins of hepatitis C virus, and T helper 1 (Th1)-like responses to NS3 in humans correlate with clearance of infection. Several studies have proposed that DNA-based immunizations are highly immunogenic and prime Th1-like responses, although few head-to-head comparisons with exogenous protein immunizations have been described. A full-length NS3/NS4A gene was cloned in eukaryotic vectors with expression directed to different subcellular compartments. Inbred mice were immunized twice in regenerating tibialis anterior (TA) muscles with either plasmid DNA or recombinant NS3 (rNS3). After two 100 micrograms DNA immunizations, specific antibody titres of up to 12960 were detected at week 5, dominated by IgG2a and IgG2b. NS3-specific CD4(+) T cell responses in DNA-immunized mice peaked at day 13, as measured by proliferation and IL-2 and IFN-gamma production. Mice immunized with 1-10 micrograms rNS3 without adjuvant developed antibody titres comparable to those of the DNA-immunized mice, but dominated instead by IgG1. CD4(+) T cell responses in these mice showed peaks of IL-2 response at day 3 and IL-6 and IFN-gamma responses at day 6. With adjuvant, rNS3 was around 10-fold more immunogenic with respect to speed and magnitude of the immune responses. Thus, immunization with rNS3 in adjuvant is superior to DNA immunization with respect to kinetics and quantity in priming specific antibodies and CD4(+) T cells. However, as a DNA immunogen, NS3 elicits stronger Th1-like immune responses, whereas rNS3 primes a mixed Th1/Th2-like response regardless of the route, dose or adjuvant.

Cytokine network in nonresponding chronic hepatitis C patients with genotype 1: role of triple therapy with interferon alpha, ribavirin, and ursodeoxycholate

OBJECTIVE

(i) to characterize the profile of tumor necrosis factor alpha (TNF alpha), interleukin-6 (IL-6), IL 10, Fas-ligand and transforming growth factor beta (TGF beta), chronic hepatitis C (HCV) patients with genotype 1; (ii) to determine the influence of triple therapy (TT) with interferon alpha (IFN alpha) + ribavirin + ursodeoxycholic acid on these cytokines and (iii) to establish the relationship between the pro-inflammatory cytokines and the outcome of treatment.

DESIGN AND METHODS

22 patients infected with HCV-genotype 1 a/b and non responsive to IFN-alpha monotherapy were enrolled in the TT. The controls were 49 HCV naïve patients with genotype 1 a/b. Cytokine levels were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

The baseline TNF alpha values (pg/mL) in the sustained responders (SRs) (63+/-3) were significantly lower than non-responders (NRs) (140+/-16) (p < 0.001). Baseline Fas (ng/mL) levels were also lower in SRs (4.3+/-0.2) than NRs (5.4+/-0.4) (p < 0.05).

CONCLUSIONS

Fas and TNF alpha may be used as serological markers of inflammation and effectiveness of therapy.

Cytokines as predictors for sustained response and as markers for immunomodulation in patients with chronic hepatitis C

OBJECTIVES

(i) To characterize serum cytokine levels of tumor necrosis factor alpha (TNF alpha), interleukin 6 (IL 6), IL 8 and IL 12 in non-cirrhotic patients with chronic hepatitis C, (ii) to correlate the levels of these cytokines with the degree of the disease at the basal level, (iii) to correlate these levels with the response to therapy, (iv) to compare profiles of cytokines in monotherapy (MT) versus combination therapy (CT), and (v) to compare the immunomodulatory effects of MT versus CT.

DESIGN AND METHODS

47 patients were enrolled in the study. The controls were 120 volunteers (recruited from students and staff) that did not present HCV RNA positive and were not known to suffer any other metabolic disease. Thirty patients formed the other group of controls, with alcoholic liver disease (ALD). Serum cytokine levels were assessed using enzyme-linked immunosorbent assay (ELISA).

RESULTS

The sustained responders (SRs) have basal values much lower than relapsed responders (RRs) and non-responders (NRs) regardless of the therapy.

CONCLUSIONS

Cytokines can be used as non-invasive markers for sustained response and as monitors for the outcome of therapy.

Current and future therapies of hepatitis C

With recent advances in the treatment of chronic hepatitis C, patients with elevated aminotransferase levels, detectable HCV RNA in the serum, and chronic inflammation are candidates for therapy. The best initial therapy is interferon plus ribavirin, achieving a sustained response rate in 40% of patients. The duration of therapy should be based on HCV genotype (48 weeks for genotype 1; 24 weeks for other genotypes). Serum HCV RNA should be measured at week 24 to assess response and guide further therapy in patients with genotype 1 infection. Patients unsuitable for combination therapy can be treated with interferon monotherapy. Side effects, dose modification and discontinuation are generally more frequent with interferon plus ribavirin, but can be managed with close follow-up and careful monitoring. With rapid developments in treatment, new therapies will require careful prospective evaluation according to HCV genotype and viral-load characteristics. Recommendations for therapy will probably change every few years, and novel approaches may provide effective therapy for most patients with hepatitis C.

Prevalence of HIV, hepatitis B, and hepatitis C in people with severe mental illness

OBJECTIVES

This study assessed seroprevalence rates of HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV) among individuals with severe mental illness.

METHODS

Participants (n = 931) were patients undergoing inpatient or outpatient treatment in Connecticut, Maryland, New Hampshire, or North Carolina.

RESULTS

The prevalence of HIV infection in this sample (3.1%) was approximately 8 times the estimated US population rate but lower than rates reported in previous studies of people with severe mental illness. Prevalence rates of HBV (23.4%) and HCV (19.6%) were approximately 5 and 11 times the overall estimated population rates for these infections, respectively.

CONCLUSIONS

Elevated rates of HIV, HBV, and HCV were found. Of particular concern are the high rates of HCV infection, which are frequently undetected. Individuals with HCV infection commonly fail to receive appropriate treatment to limit liver damage and unknowingly may be a source of infection to others.

High-dose interferon plus ribavirin in chronic hepatitis C not responding to recombinant alpha-interferon

BACKGROUND

Recently, the combination treatment of recombinant alpha-interferon plus ribavirin has been proposed for chronic hepatitis C patients unresponsive to previous therapy with recombinant alpha-interferon alone.

AIM

To determine the effectiveness of the combination therapy for the re-treatment of chronic hepatitis C patients unresponsive to previous interferon therapy. Immediate and long-term follow-up data are reported.

PATIENTS AND METHODS

A series of 100 patients with chronic hepatitis C not responding to recombinant alpha-interferon 3 MU tiw, were randomly assigned to two groups of 50 patients each: Group A, treated with recombinant alpha-interferon therapy for an additional six months but at a double dosage (6 MU tiw) in association with ribavirin. Group B, same treatment as group A but without ribavirin. All patients responsive to therapy were then followed-up for at least 12 months. At the end of the treatment and at the end of the follow-up period, we distinguished between complete responses (return to normal of alanine aminotransferase with undetectable serum HCV-RNA] and biochemical responses (return to normal of alanine aminotransferase still with detectable viraemia).

RESULTS

Side-effects were observed only in patients treated with recombinant alpha-interferon plus ribavirin: 12% discontinued the therapy due to haemolytic anaemia. In group A, the percentages of end-of-treatment complete response, end-of-treatment biochemical response, sustained complete response, and sustained biochemical response, were 38%, 20%, 8%, and 14%, respectively, whilst in group B, these percentages were 12%, 16%, 6%, and 16%, respectively.

CONCLUSION

The results indicate that in patients with chronic hepatitis C unresponsive to previous recombinant alpha-interferon therapy, re-treatment with higher recombinant alpha-interferon doses, either alone or in combination with ribavirin, lead to mild long-term benefit. However, the satisfactory end of treatment complete response in group A suggests that a significant percentage of patients are sensitive to the combination therapy; and that a more aggressive therapeutic protocol in this selected subset of patients could result in a larger number of long-lasting responses leading, in turn, to a more favourable cost-effect ratio.

Hepatitis C: retreatment and treatment of patients with renal failure

This paper addresses two difficult issues in the treatment of hepatitis C: patients who fail to achieve a sustained response after the first course of treatment, and those who simultaneously suffer from chronic renal failure. With the recent improvements in firstline treatment, retreatment is mainly applicable to those who have previously received 6-month of interferon monotherapy at 3 MU thrice weekly. For those who had an end-of-treatment response but relapsed, there is a choice between interferon monotherapy at increased dose and/or duration of treatment, or a 6-month course of combination therapy. Retreatment of non-responders is generally unsuccessful, but some patients may respond to interferon-alpha 3 MU and ribavirin 1.0-1.2 g/day. For patients with chronic renal failure and hepatitis C, combination treatment is not possible because ribavirin is contraindicated. Interferon given at a dose of 1.5 MU thrice weekly was reported to be fairly well tolerated by patients who were on dialysis and resulted in end-of-treatment and sustained biochemical and virological response in some cases. Interferon given in the usual doses may be associated with severe adverse effects in patients with renal failure, and can precipitate allograft rejection in patients who have undergone renal transplantation.

Combination Interferon alfa-2b/ribavirin therapy for the treatment of hepatitis C: nursing implications

An effective new therapeutic option consisting of Intron A (Interferon alfa-2b, recombinant; Schering Corporation, Kenilworth, NJ) Injection and Rebetol (Ribavirin, USP) Capsules is now available for the initial therapy of patients with hepatitis C and for patients who had previously responded to alpha interferon but subsequently relapsed. The combination of recombinant interferon alfa-2b/ribavirin therapy increases hepatitis C viral clearance 10-fold in hepatitis C relapse patients and almost threefold in previously untreated patients compared with alpha interferon monotherapy. There is no synergistic toxicity apparent with the two-drug combination. Ribavirin does not significantly worsen the side effects associated with interferon alfa-2b, which are predictable, manageable, and reversible. The major side effects of combination therapy include flulike symptoms, neutropenia, psychiatric disorders, and anemia; however, these side effects are well known and can be managed with dose modifications and nursing intervention. The assistance of nurses in patient education, in side effect management, in hematologic parameter monitoring, and in medication dosing and administration is crucial to maximizing patient compliance and therapy outcome.

Interferon plus ribavirin in chronic hepatitis C non-responders to recombinant alpha-interferon

The aim of this study was to evaluate the most appropriate therapeutic protocol for patients with chronic hepatitis C not responding to a previous course of recombinant interferon alpha-2b (rIFN). Sixty patients were randomly assigned to two groups of 30 subjects each: group A was treated with double dose of the same type of rIFN (6 MU t.i.w.) plus ribavirin for 6 months; group B was treated with the same rIFN dose and duration as group A, but without ribavirin. An end of treatment complete response (ETCR) was defined as alanine transaminase (ALT) normalization with undetectable serum HCV-RNA at the end of the treatment, while an end of treatment biochemical response (ETBR) as ALT normalization with still detectable viraemia. The two groups were homogeneous. The patients with ETCR or ETBR were than followed-up for at least 1 year. A sustained biochemical response (SBR) was defined as the persistence of normal ALT with still detectable viraemia after a 12-month follow-up, and a sustained complete response (SCR) as the persistence of normal ALT with undetectable viraemia. Side-effects were only observed in patients treated with rIFN plus ribavirin: four cases (13%) discontinued the therapy owing to haemolytic anaemia. Combination therapy induced an ETCR in 11 patients (37%) and an ETBR in six (20%), while a SCR was observed in two subjects (7%) and a SBR in four (13%). The use of a double dose of rIFN alone obtained an ETCR in four cases (13%) and an ETBR in five (17%), with a SCR in two (7%) and a SBR in three (10%). Hence, both combination therapy and single treatment with higher rIFN doses were unable to show statistically significant long-term benefits in patients with chronic hepatitis C resistant to a previous course of rIFN treatment.

Incidence and treatment of hepatitis C virus infection in children with haemophilia in Poland

In 80% of children with haemophilia treated in our department, screening tests showed the presence of antibodies against the hepatitis C virus (HCV). HCV RNA was detected in serum in 41% of cases. In 20% of cases there were periodic increases in the level of alanine aminotransferase (ALT) activity, and in these cases liver biopsy was performed after factor concentrate replacement. No haemorrhagic complications or pain complaints were reported either during the biopsy or immediately afterwards. In all cases histopathological examination revealed chronic hepatitis type C - chronic mild hepatitis and chronic minimal hepatitis. Eight boys were treated with interferon (INF) alpha. In two cases this therapy was successful. No HCV RNA was detected in serum and transaminase activity was normal during the year following interferon treatment.

Response to retreatment with interferon-alpha plus ribavirin in chronic hepatitis C patients is independent of the NS5A gene nucleotide sequence

OBJECTIVE

Interferon-alpha plus ribavirin is an effective treatment for chronic hepatitis C patients. We evaluated whether the response to this combined therapy correlated with the presence of mutations in a region of 372 nucleotides within the NS5A gene.

METHODS

Sixty-two patients, 42 nonresponders and 20 relapsers to a previous course of interferon-alpha, received 3 million units thrice weekly of interferon-alpha-2b and 1-1.2 g daily of ribavirin for 12 months. Basal biochemical and virological (HCV RNA and genotype) parameters were determined. Clinical examinations were carried out at 1, 2, 3, 6, and 12 months. In addition, nucleotide sequencing of the NS5A gene was determined for viral samples obtained from 38 of these patients at the baseline of the combined therapy, as well as in 15 of them before initiating the previous course of interferon as monotherapy.

RESULTS

On finishing the 12 months, 36 patients (58.1%) had normal aminotransferases and 25 (40.3%) cleared viremia. Nucleotide sequencing indicated the same level of genetic variability within the group of responder and nonresponder patients all along the 124 amino acid residues of the NS5A gene studied. Neither the type of amino acid substitution nor the number of them was significantly different in one group relative to the other.

CONCLUSIONS

Therapy with interferon-alpha-2b plus ribavirin was well tolerated, achieving an end-of-treatment response in 25 (40.3%) patients. Response did not correlate with the presence of mutations in the NS5A gene analyzed, including the interferon sensitivity determining region (ISDR) and its flanking sequences.

Interferon alpha-2B and ribavirin in combination for patients with chronic hepatitis C who failed to respond to, or relapsed after, interferon alpha therapy: a randomized trial

PURPOSE

To assess the efficacy of interferon alpha-2b and ribavirin in combination in the treatment of patients with chronic hepatitis C who had either failed to respond to therapy with interferon alpha (nonresponders), or who had relapsed after interferon therapy (relapsers).

SUBJECTS AND METHODS

Four hundred patients with chronic hepatitis C (200 nonresponders and 200 relapsers) were randomly assigned in equal numbers to receive either subcutaneous administration of recombinant interferon alpha-2b (3 million units three times per week) and ribavirin (1,000 to 1,200 mg/daily orally) or interferon alpha-2b alone (6 million units three times per week). Both ribavirin and interferon alpha-2b were given for 24 weeks. The patients were then followed for an additional 24 weeks.

RESULTS

At the end of the treatment period, normalization of serum alanine aminotransferase levels and absence of hepatitis C virus RNA were seen in 21% of nonresponders and in 39% of relapsers who were treated with interferon alpha-2b and ribavirin, compared with 5% of nonresponders (P = 0.001) and 9% of relapsers treated with interferon alpha-2b alone (P <0.001). At the end of follow-up, 14% of nonresponders and 30% of relapsers treated with the combination therapy had a sustained response, compared with 1% of nonresponders (P = 0.001) and 5% of relapsers treated with interferon alpha alone (P <0.001).

CONCLUSIONS

A 24-week course of treatment with interferon alpha-2b and ribavirin offers a chance of sustained response, whereas retreatment with interferon alpha-2b alone does not give satisfactory results. The role of long-term therapy in inducing prolonged remission remains to be explored.

Combination therapy for chronic hepatitis C: interferon and ribavirin

Hepatitis C virus (HCV) infection is one of the commonest causes of liver cirrhosis and hepatocellular carcinoma. This review deals with treatment of chronic HCV infection with a combination of interferon and ribavirin. Recent trials have shown that approximately 40% of patients will clear HCV with combination treatment. This is an important advance in the treatment of this serious viral infection.

Chronic hepatitis C virus infections in brazilian patients: association with genotypes, clinical parameters and response to long term alpha interferon therapy

The present study assessed the clinical significance of hepatitis C virus (HCV) genotypes and their influence on response to long term recombinant-interferon-alpha (r-IFN-alpha) therapy in Brazilian patients. One hundred and thirty samples from patients previously genotyped for the HCV and with histologically confirmed chronic hepatitis C (CH-C) were evaluated for clinical and epidemiological parameters (sex, age, time of HCV infection and transmission routes). No difference in disease activity, sex, age or mode and time of transmission were seen among patients infected with HCV types 1, 2 or 3. One hundred and thirteen of them were treated with 3 million units of r-IFN-alpha, 3 times a week for 12 months. Initial response (IR) was significantly better in patients with genotype 2 (100%) and 3 (46%) infections than in patients with genotype 1 (29%) (p < 0. 005). Among subtypes, difference in IR was observed between 1b and 2 (p < 0.005), and between 1b and 3a (p < 0.05). Sustained response (SR) was observed in 12% for (sub)type 1a, 13% for 1b, 19% for 3a, and 40% for type 2; significant differences were found between 1b and 2 (p < 0.001), and between 1b and 3a (p < 0.05). Moreover, presence of cirrhosis was significantly associated with non response and response with relapse (p < 0.05). In conclusion, non-1 HCV genotype and lack of histological diagnosis of cirrhosis were the only baseline features associated with sustained response to treatment. These data indicate that HCV genotyping may have prognostic relevance in the responsiveness to r-IFN-alpha therapy in Brazilian patients with chronic HCV infection, as seen in other reports worldwide.

Paricalcitol Injection and Ribavirin/Interferon Alfa-2b

Each month, subscribers to The Formulary® receive print and electronic versions of at least six monographs reviewing new drug entities or related drugs within a category. Some reviews take a second look at currently available drugs, whereas other preliminarily evaluate agents about to be released–just in time for use with your Pharmacy and Therapeutics Committee or for counter detailing. The monographs are prepared by clinical and drug-information pharmacists and are reviewed by expert pharmacists and physicians. Through the cooperation of The Formulary, Hospital Pharmacy has arranged to publish selected reviews in this column. If you would like more information about The Formulary or its related electronic bulletin board, known as the F.I.X.® (Formulary Information Exchange, write to: The Formulary, 33971 Selva Road, Suite 250, Dana Point CA 92629; or call 1-800-322-4349.

Hepatitis C virus NS3/4A protease

Despite an urgent medical need, a broadly effective anti-viral therapy for the treatment of infections with hepatitis C viruses (HCVs) has yet to be developed. One of the approaches to anti-HCV drug discovery is the design and development of specific small molecule drugs to inhibit the proteolytic processing of the HCV polyprotein. This proteolytic processing is catalyzed by a chymotrypsin-like serine protease which is located in the N-terminal region of non-structural protein 3 (NS3). This protease domain forms a tight, non-covalent complex with NS4A, a 54 amino acid activator of NS3 protease. The C-terminal two-thirds of the NS3 protein contain a helicase and a nucleic acid-stimulated nucleoside triphosphatase (NTPase) activities which are probably involved in viral replication. This review will focus on the structure and function of the serine protease activity of NS3/4A and the development of inhibitors of this activity.

Interferon alpha with ribavirin for the treatment of chronic hepatitis C in non-responders or relapsers to interferon monotherapy

BACKGROUND

A more effective therapy for chronic hepatitis C virus-infected patients is needed.

AIM

To evaluate the efficacy, tolerance and timing of response to interferon alpha plus ribavirin in 60 patients with no response or reactivation after interferon alpha alone.

METHODS

Sixty patients, 42 non-responders and 18 relapsers, received 3 million units three times weekly of interferon alpha-2b plus 1-1.2 g ribavirin daily, for 6 months. Basal biochemical and virological (HCV RNA and genotype) parameters were determined. Clinical examination, recording adverse effects, and laboratory tests, including viraemia, were carried out at 1, 2, 3 and 6 months.

RESULTS

A significant (P < 0.001) progressive decrease of HCV RNA and alanine transaminase (ALT) levels was observed during treatment. On finalizing the sixth month, 42 patients (70%) had normal ALT and 26 (43.3%) were HCV RNA negative. Of these 26 complete responders, in 20 the viraemia was undetectable by the third month, while a late clearance at the sixth month of treatment was observed in six patients. Response rates were higher in previous responders to interferon alone (P < 0.05). Mild adverse effects appeared in 46 patients (79.6%), but only three were withdrawn due to serious side-effects. Significantly (P < 0.001), haemoglobin and leucocytes decreased, and bilirubin, ferritin and uric acid increased in the first month of treatment, with no changes thereafter.

CONCLUSIONS

Interferon alpha plus ribavirin progressively decreased HCV RNA and ALT levels, achieving a complete response in the six months of treatment in 26 (43.3%) patients. This combined therapy was well tolerated.