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GASTROENTEROLOGY 1998;115:255-256 GASTROENTEROLOGY NEWS
New Therapy Packs Powerful One-Two Punch Against HCV
A leading hepatologist refers to the recently approved combination antiviral
therapy for chronic Hepatitis C (HCV) as a significant breakthrough.
Rebetron, manufactured by Schering-Plough Corp., (Kenilworth, NJ) consists
of a 6-month course of interferon injections combined with ribavirin capsules.
It was approved by the FDA in June for adult Hepatitis C patients who initially
respond to and later relapse with standard treatment (interferon alone).
An estimated 4 million Americans are believed to be infected with HCV. The
virus is responsible for about 10,000 deaths a year in this country, and is
the leading indication for liver transplantation.
Interferon alone eliminates the virus in only 10%-20% of patients, but another
25%-40% respond and subsequently relapse. In patients for whom the FDA approved
the therapy, nearly half experienced a sustained remission (6 months or more)
when administered the interferon/ribavirin combination in trials held in both
the United States and Europe, roughly 10-fold better than the patients who received
interferon alone.
Although the FDA approved the therapy specifically for the subgroup of patients
who relapse after responding to interferon alone, physicians will be able to
prescribe the treatment for patients as a first course. While the FDA has not
yet reviewed the data, Willis C. Maddrey of the University of Texas Southwestern
Medical Center in Dallas notes that published results out of Europe suggest
that naive patients respond better to the combination.
From 20% to 40% of HCV patients develop cirrhosis, but the clinical complications
often take as many as 20 years to present. Maddrey points out that patients
who are not cirrhotic have shown a substantially higher response rate to the
treatment than those who are in a later stage of the disease. "I cannot see
a patient right now and accurately predict that he will or won't develop cirrhosis
in 20 years," Maddrey says. "But I can say that if you take your chances and
don't get treated, and you develop cirrhosis, you're going to be much more resistant
to treatment."
Of course, the new treatment won't be for everyone. The side effects of the
combination therapy are potentially serious, because ribavirin causes a nonimmune
hemolytic anemia, with an average drop in hemoglobin of about 2 g. "It's important
for physicians to plan for that, to test patients' hemoglobin levels before
treatment and at 2 and 4 weeks, and not to use this drug in anyone who couldn't
stand a moderate drop in hemoglobin," says Maddrey.
The combination therapy is also expensive, estimated at $6400-$8600 for the
6-month course. But Maddrey suspects that cost-efficacy studies will ultimately
support the new therapy's use.
As for the slight majority of HCV patients who don't respond to the Rebetron,
Maddrey predicts that the next breakthrough will come with the addition, not
substitution, of another antiviral drug, possibly a protease inhibitor, to the
combination treatment. "It's similar to what occurred in AIDS, where we did
well with AZT for awhile, but the real breakthrough came when we added a protease
inhibitor to the AZT," he says. "We feel that multidrug therapy is the wave
of the future, and that hitting this virus in two or three sites gives us a
much better chance of eradication."
GASTROENTEROLOGY 1998;115:255-256
© 1998 by The American Gastroenterological Association
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