Some patients with chronic hepatitis C progress from a relatively benign condition to a life-threatening illness. Interferon has been used to try to prevent this but researchers have struggled to investigate its effects reliably. Ron Koretz from Granada Hills in the USA, tells us about the January 2013 update of the relevant Cochrane Review, outlining what the authors did to try to solve this and what they found.
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Interferon for interferon nonresponding and relapsing patients with chronic hepatitis C Updated
Published Online:
January 31, 2013
Antiviral treatment for chronic hepatitis C infections is currently judged as being successful if, at least six months after therapy, blood tests for hepatitis C viral RNA are negative; this has been called a sustained viral response. In the past, other outcomes for treatment have included improvements in biochemical tests (especially liver enzyme tests such as the serum alanine aminotransferase) or evidence of reduced inflammation and/or fibrosis on subsequent liver biopsies. All of these outcomes are tests, and it has been assumed that if the test gets better the patient will as well. However, there is no direct evidence that has proven that these outcomes are valid because there have been no long-term trials that have shown that an improvement in these tests translates into reduced mortality or morbidity. Patients who fail to have sustained viral responses after an initial course of therapy do become potential candidates for retreatment; some of them may be intolerant to ribavirin, and possibly even the newer protease inhibitors, so retreatment would have to be with interferon alone. It has also been speculated that long-term treatment (namely treatment for several years) might be beneficial; such long-term therapy would be further complicated if multiple drugs were used because of the additional drug toxicities and costs, so interferon alone could be considered.....
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Related-
Chronic hepatitis C: Interferon may be harmful in re-treatment
People with hepatitis C and chronic liver disease who relapsed or failed to respond to initial treatment are unlikely to improve on interferon retreatment. In fact, they may face an increased risk of dying sooner, and are likely to experience a variety of adverse effects, according to an updated systematic review published in The Cochrane Library.
Hepatitis C affects around 170 million people worldwide. In some cases, infection leads to chronic liver disease, liver failure or liver cancer, eventually resulting in death. Treatment is based on antiviral drugs.
Interferon monotherapy, meaning using interferon alone, is not the first choice of therapy for most clinicians, but it is used in some patients when other drugs cannot be used. Despite costing thousands of dollars to treat one patient for a year, there is currently little evidence that it works. Treatment is considered to have been successful if the virus cannot be detected in a patient's blood six months after treatment. This outcome is known as sustained viral response (SVR). However, it has never been confirmed that SVR leads to an improvement in the patient's disease state or their chances of survival.
The authors of the review analysed data from seven trials involving a total of 1,976 patients with chronic hepatitis C liver disease who were being retreated with interferon monotherapy having previously been treated unsuccessfully. When they included all trials in their analysis, the risk of death was no higher for interferon than for placebo or no treatment. However, the researchers also performed a further analysis, leaving out studies that had a high risk of bias and gave less reliable estimates of effect. For example, one of these trials was not blinded, was stopped before the planned number of patients had been enrolled, and did not have all of those who had been enrolled counted in the final analysis. This left the two largest trials, together incorporating 1,676 patients. Focusing only on these trials, the risk of death was significantly higher at 9.4% for interferon retreatment compared to 6.7% for placebo or no treatment.
"It was troubling to see that in those trials providing the most reliable estimates of treatment effects, interferon seemed to increase the risk of death," said lead researcher Ronald Koretz of Granada Hills in California, US. "Based on these results, interferon monotherapy cannot be recommended for chronic hepatitis C patients who have already failed one course of treatment and are being retreated. Furthermore, patients who are receiving interferon as part of a combination therapy should be informed about this potential adverse effect."
Interferon treatment did seem to reduce levels of hepatitis C virus in the blood compared to controls, resulting in what would be considered successful treatment or SVR. However, since this response was not associated with an improvement in disease or risk of death, the review suggests that SVR may be inadequate as an indicator of a successful treatment outcome. "Sustained viral response did not suggest that a patient who was destined to develop symptoms or death from hepatitis C was cured, at least in this setting. This tells us that as a treatment outcome it is not universally reliable and needs to be validated before it can be viewed as the goal of any therapy in other clinical scenarios," said Koretz.
Patients in the treatment group were also more likely to suffer adverse effects. Although the drug did appear to reduce the incidence of nonfatal internal bleeding, the researchers conclude that it is so expensive that it may be hard to justify based on this one small benefit.
http://www.eurekalert.org/pub_releases/2013-01/w-chc012813.php
Interferon May Be Harmful in Retreatment of Hepatitis C
Medscape
When patients with hepatitis C and chronic liver disease suffer relapses or fail to respond to initial treatment, monotherapy with interferon may not be a good idea, according to results from a recent meta-analysis. In fact, employing that approach may raise the risks for death and adverse effects.
The review is published in the January issue of the Cochrane Database of Systematic Reviews and was conducted by Ronald Koretz, MD, professor of medicine, digestive diseases and gastroenterology, David Geffen School of Medicine, University of California, Los Angeles, and colleagues.
"The widely-accepted treatment outcome for chronic hepatitis C is the sustained viral response (that is, no measurable viral RNA in blood six months after treatment). However, this surrogate outcome (as well as the previously employed biochemical and histologic ones) has never been validated," the authors write.
The lack of validation is not surprising, the authors say, because very few randomized clinical trials evaluating clinical outcomes (mortality or manifestations of cirrhosis) have been conducted, as patients usually do not die or develop cirrhosis until years after they have been infected.
Patients who undergo initial therapy but do not produce sustained viral responses become potential candidates for retreatment, the authors note, but for some patients in whom standard treatment with ribavirin or protease inhibitors cannot be tolerated, clinicians often consider retreatment with interferon to be a reasonable option.
All-Cause Mortality Worse
To find out more about the actual clinical effects of retreatment with interferon, the investigators reviewed data from 7 clinical trials in which monotherapy retreatment with interferon was compared with placebo or no treatment.
Two of the trials (the Hepatitis C Antiviral Long-term Treatment against Cirrhosis [HALT-C] and Evaluation of Peglntron in Control of Hepatitis C Cirrhosis [EPIC-3] trials) were considered to be at low risk for bias. Together, those trials included 1676 patients. Both assessed the clinical outcomes of patients with severe fibrosis who underwent long-term low-dose retreatment with pegylated interferon therapy.
The other 5 trials included a total of 300 patients and were considered to be at high risk for bias.
Dr. Koretz and colleagues report that when they included all trials with published outcomes in their review they saw no significant difference in all-cause mortality (78/843 [9.3%] vs 62/867 [7.2%]; risk ratio [RR], 1.30; 95% confidence interval [CI], 0.95 - 1.79; 3 trials). They also did not find a significant difference in hepatic-related mortality (41/532 [7.7%] vs 40/552 [7.2%]; RR, 1.07; 95% CI, 0.70 - 1.63; 2 trials).
However, when the reviewers included only the 2 trials considered at low risk for bias, they noted that all-cause mortality was significantly higher among patients who received interferon (78/828 [9.4%] vs 57/848 [6.7%]; RR, 1.41; 95% CI, 1.02 - 1.96).
They do note, however, that there was less variceal bleeding in patients who received interferon (4/843 [0.5%] vs 18/867 [2.1%]; RR, 0.24; 95% CI, 0.09 - 0.67; 3 trials). Still, the researchers comment that the prohibitive cost of interferon would not justify it for this indication alone.
Patients administered interferon were no more likely to develop ascites, encephalopathy, or hepatocellular carcinoma or to need liver transplants.
Only one of the trials included quality-of-life data, and in that trial pain scores were significantly worse in patients receiving interferon, the reviewers write. Patients receiving interferon were also more likely to suffer adverse effects, most commonly hematologic complications, infections, influenza-like symptoms, and rashes.
SVR a Surrogate Marker?
Interferon therapy did appear, however, to be associated with significantly better viral responses (20/557 [3.6%] vs 1/579 [0.2%]; RR, 15.38; 95% CI, 2.93 - 80.71; 4 trials). In addition, METAVIR activity scores, gauging degree of inflammation as well as the extent of fibrosis, also improved (36/55 [65%] vs 20/46 [43.5%]; RR, 1.49; 95% CI, 1.02 - 2.18; 2 trials). However, the reviewers say they saw no significant differences in histologic assessments of fibrosis.
The authors stress that the clinical data they reviewed were limited to patients with histologic evidence of severe fibrosis who were retreated with pegylated interferon.
"In this scenario, retreatment with interferon did not appear to provide significant clinical benefit and, when only the trials at low risk of bias were considered, retreatment for several years may even have increased all-cause mortality. Such treatment also produced adverse events," the authors note.
In conclusion, they write, "Two of the commonly employed surrogate markers, sustained viral response and markers of inflammation, failed to be validated since they improved even though the clinical outcomes did not (or may even have become worse). This failure to validate the sustained viral response in this group of patients with a low sustained viral response rate suggests that the presumed validity of the use of sustained viral responses in other groups of patients with chronic hepatitis C viral infections who receive treatment must be formally validated."
The authors have disclosed no relevant financial relationships.
Cochrane Database Syst Rev. 2013:1:CD003617.
Related-
Chronic hepatitis C: Interferon may be harmful in re-treatment
People with hepatitis C and chronic liver disease who relapsed or failed to respond to initial treatment are unlikely to improve on interferon retreatment. In fact, they may face an increased risk of dying sooner, and are likely to experience a variety of adverse effects, according to an updated systematic review published in The Cochrane Library.
Hepatitis C affects around 170 million people worldwide. In some cases, infection leads to chronic liver disease, liver failure or liver cancer, eventually resulting in death. Treatment is based on antiviral drugs.
Interferon monotherapy, meaning using interferon alone, is not the first choice of therapy for most clinicians, but it is used in some patients when other drugs cannot be used. Despite costing thousands of dollars to treat one patient for a year, there is currently little evidence that it works. Treatment is considered to have been successful if the virus cannot be detected in a patient's blood six months after treatment. This outcome is known as sustained viral response (SVR). However, it has never been confirmed that SVR leads to an improvement in the patient's disease state or their chances of survival.
The authors of the review analysed data from seven trials involving a total of 1,976 patients with chronic hepatitis C liver disease who were being retreated with interferon monotherapy having previously been treated unsuccessfully. When they included all trials in their analysis, the risk of death was no higher for interferon than for placebo or no treatment. However, the researchers also performed a further analysis, leaving out studies that had a high risk of bias and gave less reliable estimates of effect. For example, one of these trials was not blinded, was stopped before the planned number of patients had been enrolled, and did not have all of those who had been enrolled counted in the final analysis. This left the two largest trials, together incorporating 1,676 patients. Focusing only on these trials, the risk of death was significantly higher at 9.4% for interferon retreatment compared to 6.7% for placebo or no treatment.
"It was troubling to see that in those trials providing the most reliable estimates of treatment effects, interferon seemed to increase the risk of death," said lead researcher Ronald Koretz of Granada Hills in California, US. "Based on these results, interferon monotherapy cannot be recommended for chronic hepatitis C patients who have already failed one course of treatment and are being retreated. Furthermore, patients who are receiving interferon as part of a combination therapy should be informed about this potential adverse effect."
Interferon treatment did seem to reduce levels of hepatitis C virus in the blood compared to controls, resulting in what would be considered successful treatment or SVR. However, since this response was not associated with an improvement in disease or risk of death, the review suggests that SVR may be inadequate as an indicator of a successful treatment outcome. "Sustained viral response did not suggest that a patient who was destined to develop symptoms or death from hepatitis C was cured, at least in this setting. This tells us that as a treatment outcome it is not universally reliable and needs to be validated before it can be viewed as the goal of any therapy in other clinical scenarios," said Koretz.
Patients in the treatment group were also more likely to suffer adverse effects. Although the drug did appear to reduce the incidence of nonfatal internal bleeding, the researchers conclude that it is so expensive that it may be hard to justify based on this one small benefit.
http://www.eurekalert.org/pub_releases/2013-01/w-chc012813.php
Interferon May Be Harmful in Retreatment of Hepatitis C
Medscape
When patients with hepatitis C and chronic liver disease suffer relapses or fail to respond to initial treatment, monotherapy with interferon may not be a good idea, according to results from a recent meta-analysis. In fact, employing that approach may raise the risks for death and adverse effects.
The review is published in the January issue of the Cochrane Database of Systematic Reviews and was conducted by Ronald Koretz, MD, professor of medicine, digestive diseases and gastroenterology, David Geffen School of Medicine, University of California, Los Angeles, and colleagues.
"The widely-accepted treatment outcome for chronic hepatitis C is the sustained viral response (that is, no measurable viral RNA in blood six months after treatment). However, this surrogate outcome (as well as the previously employed biochemical and histologic ones) has never been validated," the authors write.
The lack of validation is not surprising, the authors say, because very few randomized clinical trials evaluating clinical outcomes (mortality or manifestations of cirrhosis) have been conducted, as patients usually do not die or develop cirrhosis until years after they have been infected.
Patients who undergo initial therapy but do not produce sustained viral responses become potential candidates for retreatment, the authors note, but for some patients in whom standard treatment with ribavirin or protease inhibitors cannot be tolerated, clinicians often consider retreatment with interferon to be a reasonable option.
All-Cause Mortality Worse
To find out more about the actual clinical effects of retreatment with interferon, the investigators reviewed data from 7 clinical trials in which monotherapy retreatment with interferon was compared with placebo or no treatment.
Two of the trials (the Hepatitis C Antiviral Long-term Treatment against Cirrhosis [HALT-C] and Evaluation of Peglntron in Control of Hepatitis C Cirrhosis [EPIC-3] trials) were considered to be at low risk for bias. Together, those trials included 1676 patients. Both assessed the clinical outcomes of patients with severe fibrosis who underwent long-term low-dose retreatment with pegylated interferon therapy.
The other 5 trials included a total of 300 patients and were considered to be at high risk for bias.
Dr. Koretz and colleagues report that when they included all trials with published outcomes in their review they saw no significant difference in all-cause mortality (78/843 [9.3%] vs 62/867 [7.2%]; risk ratio [RR], 1.30; 95% confidence interval [CI], 0.95 - 1.79; 3 trials). They also did not find a significant difference in hepatic-related mortality (41/532 [7.7%] vs 40/552 [7.2%]; RR, 1.07; 95% CI, 0.70 - 1.63; 2 trials).
However, when the reviewers included only the 2 trials considered at low risk for bias, they noted that all-cause mortality was significantly higher among patients who received interferon (78/828 [9.4%] vs 57/848 [6.7%]; RR, 1.41; 95% CI, 1.02 - 1.96).
They do note, however, that there was less variceal bleeding in patients who received interferon (4/843 [0.5%] vs 18/867 [2.1%]; RR, 0.24; 95% CI, 0.09 - 0.67; 3 trials). Still, the researchers comment that the prohibitive cost of interferon would not justify it for this indication alone.
Patients administered interferon were no more likely to develop ascites, encephalopathy, or hepatocellular carcinoma or to need liver transplants.
Only one of the trials included quality-of-life data, and in that trial pain scores were significantly worse in patients receiving interferon, the reviewers write. Patients receiving interferon were also more likely to suffer adverse effects, most commonly hematologic complications, infections, influenza-like symptoms, and rashes.
SVR a Surrogate Marker?
Interferon therapy did appear, however, to be associated with significantly better viral responses (20/557 [3.6%] vs 1/579 [0.2%]; RR, 15.38; 95% CI, 2.93 - 80.71; 4 trials). In addition, METAVIR activity scores, gauging degree of inflammation as well as the extent of fibrosis, also improved (36/55 [65%] vs 20/46 [43.5%]; RR, 1.49; 95% CI, 1.02 - 2.18; 2 trials). However, the reviewers say they saw no significant differences in histologic assessments of fibrosis.
The authors stress that the clinical data they reviewed were limited to patients with histologic evidence of severe fibrosis who were retreated with pegylated interferon.
"In this scenario, retreatment with interferon did not appear to provide significant clinical benefit and, when only the trials at low risk of bias were considered, retreatment for several years may even have increased all-cause mortality. Such treatment also produced adverse events," the authors note.
In conclusion, they write, "Two of the commonly employed surrogate markers, sustained viral response and markers of inflammation, failed to be validated since they improved even though the clinical outcomes did not (or may even have become worse). This failure to validate the sustained viral response in this group of patients with a low sustained viral response rate suggests that the presumed validity of the use of sustained viral responses in other groups of patients with chronic hepatitis C viral infections who receive treatment must be formally validated."
The authors have disclosed no relevant financial relationships.
Cochrane Database Syst Rev. 2013:1:CD003617.
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