Fosamprenavir paediatric dosing approved in US for ages 4 weeks to <6 years

On 27 April 2012, the Food and Drug Administration approved dosing recommendations for use of fosamprenavir (Lexiva) oral suspension in pediatric patients.

Data submitted to FDA included three studies to support a new dosing regimen for fosamprenavir (FOS), with ritonavir (RTV), in combination with other antiretroviral drugs, for the treatment of HIV-1 infection in pediatric patients from at least 4 weeks to less than 6 years of age.

The fosamprenavir label now includes dosing for pediatric patients aged at least 4 weeks to 18 years. The dosage of fosamprenavir should be calculated based on body weight (kg) and not exceed the recommended adult dose.

Twice daily dosage regimens by weight with ritonavir are as follows:

  • For protease inhibitor-naïve pediatric patients (greater than or equal to 4 weeks of age) and
  • For protease inhibitor-experienced pediatric patients greater than or equal to 6 months of age. (fosamprenavir plus ritonavir is not recommended for protease inhibitor experienced pediatric patients less than 6 month of age.)
Less than 11 kg FOS 45 mg/kg plus RTV 7 mg/kg
11 kg to less than 15 kg FOS 30 mg/kg plus RTV 3 mg/kg
15 kg to less than 20 kg FOS 23 mg/kg plus RTV 3 mg/kg
Greater than and equal to 20 kg FOS 18 mg/kg plus RTV 3 mg/kg

Alternatively, protease inhibitor naïve children 2 years of age and older can be administered fosamprenavir (without ritonavir) 30 mg/kg twice daily. Fosamprenavir should only be administered to infants born at 38 weeks gestation or greater and who have attained a post-natal age of 28 days. For pediatric patients, pharmacokinetic and clinical data:

  • Do not support once-daily dosing of fosamprenavir alone or in combination with ritonavir.
  • Do not support administration of fosamprenavir alone or in combination with ritonavir for protease inhibitor-experienced children younger than 6 months of age.
  • Do not support twice-daily dosing of fosamprenavir without ritonavir in pediatric patients younger than 2 years of age.

Other sections were updated to include safety and activity data from the three open label trials in pediatric subjects aged at least 4 weeks to 18 years.

The complete updated labeling will be posted soon to on the FDA web site. Fosamprenavir is an HIV protease inhibitor manufactured by GlaxoSmithKline.

Links to other websites are current at date of posting but not maintained.