A desensitization protocol in children with L-asparaginase hypersensitivity

Area of Science:

• Oncology
• Pediatric Hematology/Oncology
• Pharmacology

Background:

• L-asparaginase is a crucial chemotherapeutic agent for various malignant diseases.
• Hypersensitivity reactions to L-asparaginase occur in 5% to 45% of patients, often necessitating treatment cessation.
• Managing L-asparaginase hypersensitivity is critical for effective cancer treatment in pediatric populations.

Purpose of the Study:

• To evaluate the safety and efficacy of a desensitization protocol for children experiencing hypersensitivity to native E. coli L-asparaginase.
• To determine if continued administration of native E. coli L-asparaginase is feasible following a desensitization regimen.
• To assess the potential for safe re-challenge with L-asparaginase in pediatric patients with a history of allergic reactions.

Main Methods:

• A cohort of 9 pediatric patients with leukemia or Langerhans cell histiocytosis and prior L-asparaginase hypersensitivity underwent desensitization.
• Pre-medication included intravenous dexamethasone and pheniramine hydrogen maleate administered one hour before L-asparaginase infusions.
• A graded dose escalation of native E. coli L-asparaginase was administered intravenously over 4 hours per dose, totaling 20 hours.

Main Results:

• None of the 9 patients experienced recurrent hypersensitivity reactions after undergoing the desensitization protocol.
• Patients received a median of 6 subsequent doses (68 doses total) of native E. coli L-asparaginase without adverse events.
• The desensitization protocol demonstrated a high success rate in preventing allergic reactions during continued L-asparaginase therapy.

Conclusions:

• The implemented desensitization protocol is safe and effective for managing L-asparaginase hypersensitivity in pediatric cancer patients.
• This protocol enables the continued use of native E. coli L-asparaginase, crucial for maintaining therapeutic efficacy.
• Desensitization represents a viable strategy to overcome hypersensitivity barriers in L-asparaginase treatment.