Monday, December 17, 2012

Ribavirin dose reduction, erythropoietin combat HCV anemia

By: NEIL OSTERWEIL, Family Practice News Digital Network

BOSTON – Anemia developed significantly more often among patients with hepatitis C virus infection and compensated cirrhosis than among noncirrhotic patients during triple therapy in a randomized, open-label trial of treatment-naive patients, but in most instances the anemia was effectively treated.

In an anemia management subanalysis of a study comparing sustained virologic response (SVR) rates in cirrhotic and noncirrhotic patients treated with boceprevir (Victrelis), pegylated interferon alfa-2b (Peg-Intron), and ribavirin (RBV), 57% of patients with cirrhosis and anemia treated with a ribavirin dose reduction had an SVR, compared with 64% of those treated with erythropoietin. Among noncirrhotic patients with anemia, the respective SVR rates were 73% and 72%; none of the differences was significant, Dr. Eric J. Lawitz reported at the annual meeting of the American Association for the Study of Liver Diseases.

Courtesy US. Dept of Veterans Affairs

"Sustained viral responses are comparable in cirrhotic patients when anemia is managed by ribavirin dose reduction or erythropoietin," said Dr. Eric J. Lawitz.

"Sustained viral responses are comparable in cirrhotic patients when anemia is managed by ribavirin dose reduction or erythropoietin," said Dr. Lawitz, medical director and principal investigator at Alamo Medical Research in San Antonio, Tex., adding that ribavirin dose reductions should be the initial strategy for managing anemia, followed, if necessary, by erythropoietin.

In the trial, 687 treatment-naive patients with hepatitis C virus (HCV) infections were treated for 4 weeks with pegylated interferon (PEG-IFN) alfa-2b and RBV, then 24 or 44 weeks of boceprevir added in. Baseline hemoglobin levels ranged from 12 g/dL to15 g/dL for women, and from 13 g/dL to15 g/dL for men.

Patients with a hemoglobin level approaching 10 g/dL or less (tested from baseline through week 48) were randomized to either ribavirin dose reduction (249 patients) in 200-mg increments (first increment of 400 mg for initial 1,400-mg daily doses) at the investigators’ discretion, or to erythropoietin (251 patients) at 40,000 U/wk, modifiable to 20,000 U/wk or 60,000 U/wk at the investigator’s discretion. The remaining patients received anemia prophylaxis but were not randomized.

If the hemoglobin level dropped to 8.5 g/dL, patients could receive the other treatment as a secondary intervention, and patients with a hemoglobin level of 7.5 g/dL were discontinued from all study drugs.

Primary efficacy measures for all patients (cirrhotic and noncirrhotic) in each anemia strategy group were identical, with 82% having an end-of-treatment response, 71% having an SVR, and 10% experiencing relapse.

Among cirrhotic vs. noncirrhotic patients, rates were 68% vs. 76% for end-of-treatment response , 55% vs. 64% for SVR, and 18% vs. 11% for relapse.

Patients with cirrhosis were significantly more likely to require a secondary anemia intervention (44% vs. 26%, P = .009). Among noncirrhotic patients (but not cirrhotic patients), a secondary anemia intervention was associated with a greater likelihood of SVR (80% vs. 70% for only one intervention, P = .05).

Serious adverse events occurred in 20% of cirrhotic patients and 12% of noncirrhotic patients, but only one study death occurred. The noncirrhotic patient died of a cardiac arrest, which was considered to be unrelated to therapy.

Treatment-emergent adverse events occurred in 3% of patients with cirrhosis and 2% of those without cirrhosis. Drug discontinuation for adverse events occurred in 17% of cirrhotic patients, and 16% of noncirrhotic patients.

Cirrhotic patients were more likely to have hemoglobin concentrations ranging from 6.5 to 8.0 g/dL than were noncirrhotic patients, but no patient in either group had a hemoglobin concentration below 6.5 g/dL.

Neutrophil counts in the range of 500-749/mm3 occurred in 24% of cirrhotic patients and 27% of noncirrhotic patients, and counts below 500/mm3 were seen in 20% and 12%.

Platelet counts from 25,000 to 49,999/mm3 occurred in 22% of cirrhotic patients and 2% of noncirrhotic patients. Counts below 25,000/mm3 were seen in 3% vs. less than 1%, respectively. Transfusion rates were similar between the groups.

The study was funded by Merck Sharp & Dohme, which manufactures boceprevir. Dr. Lawitz disclosed receiving grant and research support from the company.

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