Basiliximab in pediatric liver transplantation: a pharmacokinetic-derived dosing algorithm

Area of Science:

• Pharmacology and Immunology
• Transplantation Medicine

Background:

• Basiliximab is an immunosuppressive monoclonal antibody used in organ transplantation.
• Optimizing basiliximab dosing in pediatric liver allograft recipients is crucial for efficacy and safety.
• Previous dosing regimens (mg/m2) showed variability in pharmacokinetics and immunodynamics in children.

Purpose of the Study:

• To determine optimal basiliximab dose regimens for pediatric liver allograft recipients.
• To assess the pharmacokinetics and immunodynamics of basiliximab in this population.
• To establish safe and effective dosing strategies for infants, children, and adolescents.

Main Methods:

• Pharmacokinetic and immunodynamic assessment of basiliximab in 37 pediatric de novo liver allograft recipients.
• Two dosing strategies were evaluated: 12 mg/m2 and fixed doses (10 mg for infants/children, 20 mg for adolescents).
• Blood samples analyzed for basiliximab and soluble interleukin-2 receptor (IL-2R) concentrations over 12 weeks; anti-idiotype antibodies screened.

Main Results:

• Basiliximab clearance was approximately 50% lower in children < 9 years compared to adults, independent of age, weight, or BSA up to specific thresholds.
• Fixed-dose regimens resulted in longer CD25 saturation durations (37 days) compared to mg/m2 dosing (27 days), with less age-related bias.
• Ascites fluid drainage influenced basiliximab exposure; supplemental doses may be needed for patients with large ascites volume.

Conclusions:

• A fixed-dose regimen of two 10-mg doses for pediatric patients < 35 kg and two 20-mg doses for those >= 35 kg is recommended.
• The first dose should be administered within 6 hours post-organ perfusion, with the second dose on day 4 post-transplant.
• Basiliximab was safe, well-tolerated, and effective in pediatric liver transplant recipients, with no significant adverse events reported.