Among infant patients with acute lymphoblastic leukemia (ALL), monitoring pegaspargase pharmacokinetics by serum asparaginase activity (SAA) appears to be an effective strategy for determining therapy efficacy, according to research presented at the 2022 American Society of Pediatric Hematology/Oncology Conference.

Asparaginase is a cornerstone of ALL treatment, and therapy efficacy monitoring through SAA is commonplace among older patients. Given that infants receive reduced body surface area–dosage compared with older patients, and further that long-term infant outcomes are generally poor, understanding the usefulness of SAA monitoring in this patient population is an important goal.

For this report from the Children’s Oncology Group Trial, AALL15P1, researchers evaluated usefulness of SAA monitoring among infants with ALL who received pegaspargase. Dosage varied in the study cohort and increased with patient age.

Continue Reading

Overall, of 78 patients enrolled to AALL15P1, 34 had 60 total SAA measurements. The authors measured SAA levels at induction (30 readings), interim maintenance (17 readings), and delayed intensification part 1 (13 readings).

Analysis showed that all patient SAA levels were greater than 0.1 IU/mL, which is the commonly used minimal therapeutic threshold. Moreover, 92% of patients had SAA levels greater than 0.4 IU/mL, which is considered the optimal therapeutic threshold.

Patients younger than 6 months had mean SAA levels of 0.57 IU/mL, while patients aged 6-11 months and older than 12 months had mean SAA levels of 0.82 IU/mL and 1.31 IU/mL, respectively (P <.001). No drug hypersensitivity reactions were noted.

“Ongoing analysis will assess for correlation of SAA levels with patient demographic factors and incidence of pegaspargase associated toxicities, and further evaluate pharmacokinetic modeling,” the authors noted.

Disclosure: The study author(s) declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Read more of Hematology Advisor’s coverage of ASPHO 2022 by visiting the conference page.


Faulk K, Kairalla J, Devidas M, et al. Pegaspargase levels in infants with acute lymphoblastic leukemia: a report from the Children’s Oncology Group Trial AALL15P1. Poster presented at: 2022 American Society of Pediatric Hematology/Oncology (ASPHO) Conference; May 4-7, 2022. Abstract 212.