Arrival of Protease Inhibitors Offers Hepatitis C Patients New Options, New Questions
By Richard Robinson
Published Online: Monday, November 12, 2012
Infectious Disease
Source- HCPLive
With
the arrival of protease inhibitors for hepatitis C, patients now have more
treatment options than ever before. How should physicians advise them on the
risks and benefits of these new treatments? Andrew Muir, MD, of Duke University
Medical Center in Durham, NC, reviewed the state of the field and offered his
own guidelines in a “Hepatology Update” session at The Liver Meeting, the
63rd Annual Meeting of the American Association for the Study of
Liver Diseases (AASLD).
The combination of treatments available now
means that “we can cure most of the patients we see,” Muir said. A critical
question in planning treatment is whether, and when, to begin with one of the
protease inhibitors. According to Muir, the question now is, “Do we treat now or
do we wait?”
There are multiple factors that influence the likely
response to the two new protease inhibitors, boceprevir and telaprevir. A
patient’s race is a principle factor affecting treatment, with African-Americans
less likely to respond to treatment with these medications than whites.
Nonetheless, Muir noted, the average benefit is still expected to be better in
these patients than for no treatment.
Other factors shown in trials to
reduce response are presence of fibrosis or cirrhosis, and viral genotype, with
genotype 1a being more difficult to treat than 1b.
IL28B genotype is
also an important factor. Patients with the CC genotype respond the best, while
those with either CT or TT do less well. Patients with the CC genotype are much
more likely to be eligible for short-duration therapy, and that often influences
their decision to move forward with treatment.
“If you have that early
response, you have an excellent chance of being cured. It just doesn't happen to
everybody,” said Muir.
For patients who are treatment-experienced, a
major predictor of benefit is response to prior therapy. Patients who originally
did well but then relapsed are likely to do best, while those with only a
partial or null response do worse. Patients who relapse “have a great chance of
being cured, even in patients with cirrhosis. This is not true for cirrhotic
patients who are partial- or non-responders. In these patients, response to
protease inhibitor treatment is very low,” Muir said. “We have to accept the
fact that these patients have a very low likelihood of being cured. Patients
need to understand that in making decisions.”
The adverse effects of the
protease inhibitors must also be considered. Among them, the potential for
anemia is significant. “This is one of the key things we have learned in the
last few months. We have to think about this as we advise patients,” Muir
said.
The clinician should anticipate a 4 to 6 gram per deciliter drop
in hemoglobin from baseline, he said. In other words, physicians should “plan
for anemia.”
Treatment strategies include a reduction in the ribavirin
dose, and adding erythropoietin. From the results of a randomized comparison
trial, their efficacy appears to be identical. “They are both reasonable
options,” Muir said, but noted that erythropoietin is not approved by the FDA
for this indication.
Omitting ribavirin altogether is usually not a good
idea, because “you don't want to put them in a position that you have to stop
ribavirin,” said Muir. “My first reduction is down to 600 milligrams” of
ribavirin, he said, with weekly monitoring until the hemoglobin is stable.
“Embrace dose reduction and you can have great response
rates.”
Reduction of peginterferon-alpha is also reasonable if the
patient is anemic.
Finally, Muir noted that protease inhibitors may have
a higher rate of serious adverse events (AEs) outside of clinical trials,
according to recent studies, which showed that serious AEs occurred in almost
half the patients on telaprevir, and almost 40% of patients on boceprevir,
leading to premature discontinuations in about a quarter of patients.
He
also pointed out that the patient must be able to take the medications
scrupulously every seven to nine hours, and attend regular follow-up visits for
monitoring.
For his own patients who do not fit the criteria used in the
trials, Muir said that he is more likely to recommend transplantation if they
are not responding well to first-line treatment.
“Peginterferon and
ribavirin remain the backbone of treatment.” But with the new treatment options,
“our conversations with patients are getting longer,” he said.
http://www.hcplive.com/conferences/aasld-2012/Arrival-of-Protease-Inhibitors-Offers-Hepatitis-C-Patients-New-Options-New-Questions
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