FDA approves Schering-Plough's Pegintron to treat paediatric hepatitis C
This article was originally published in Scrip
The US FDA has granted Schering-Plough's combination therapy of Pegintron (peginterferon alfa-2b) and Rebetol (ribavirin) marketing approval for use in previously untreated patients three years and older with chronic hepatitis C (HCV).
The company says that this represents the first and only approved peginterferon in combination with ribavirin for treating children with paediatric hepatitis C in the US. The only other treatment for treating paediatric hepatitis C is the company's conventional Intron A (interferon alfa-2b) in combination with ribavirin – which was approved for treating children aged over one year in 1998.
"With the FDA approval of Pegintron combination therapy for this new indication, US physicians now have access to the current standard of care for hepatitis C or use in treating their paediatric patients. Thankfully, the number of children with hepatitis C is small, although this chronic infection over time can lead to serious liver damage," said Dr Robert Speigel, chief medical officer and senior vice-president of Schering-Plough Research Institute.
About 130,000 children are infected with hepatitis C in the US. The most common mode of infection is through mother-to-foetus transmission – which occurs in four to 10% of HCV infected mothers.
Pegintron was first approved in 2001, both as a monotherapy and for use in combination with Rebetol. Peginterferon (pegylated interferon) is comprised of a large molecule of poly(ethylene glycol) covalently attached to a recombinant IFN- alpha, resulting in an active molecule with a longer half life, better pharmacokinetic profile and better virological response than an unconjugated interferon.
The approval of Pegintron for paediatric indication is based on data from a clinical trial in 107 previously untreated patients aged three to 17 with chronic hepatitis C and compensated liver disease. Patients infected with HCV genotypes one or four, and those with HCV genotypes three with a HCV RNA greater than 600,000 IU/ml (which is regarded as a high viral load), received 48 weeks of therapy, while those with HCV genotypes two or three with HCV RNA less than 600,000 IU/ml received 24 weeks of therapy.
The dose of Pegintron was 60μg/m2 of body surface area/week subcutaneously in combination with 15mg/kg of body weight/day of Rebetol, orally in two divided doses.
The study looked at the proportion of patients who achieved a sustained viral load (SVR), which is defined as the loss of detectable HCV RNA during treatment and its continued absence for at least six months after stopping therapy
Of the patients with HCV genotypes one, four and three (high viral load) who received 48 weeks of treatment, 55% achieved a sustained viral response. As previously seen in adult patients, sustained viral response in paediatric patients with HCV genotype two or three (low viral load) was much higher in those with genotype one; the sustained viral response rate was 90 percent in children with HCV genotype two or three (low viral load).
During the 48 week therapy course, weight loss and growth retardation was common. Furthermore, some of children who experienced growth inhibition during therapy did not regain normal growth velocity six months after the end of the treatment.