A Refined Population Pharmacokinetic Model-Based Guideline for Individualized PEGasparaginase Dosing in Pediatric
Leiah J Brigitha1,2, Karen Zaky1, Rob Pieters1
1Princess Máxima Center for Pediatric Oncology, Utrecht, the Netherlands ; and.
Insights
A new population pharmacokinetic model-based guideline for pegaspargase dosing in acute lymphoblastic leukemia significantly reduced dose adjustments needed to achieve target levels. This improved dosing strategy demonstrates high adherence and practicality for clinical integration.
Area of Science:
- Pediatric Oncology
- Pharmacokinetics
- Pharmacodynamics
Background:
- Individualized pegaspargase dosing was implemented in the Dutch Childhood Oncology Group ALL11 protocol for acute lymphoblastic leukemia.
- An older, pragmatic guideline for pegaspargase dosing was in use.
- A new population pharmacokinetic model-based guideline was developed to enhance individualized pegaspargase dosing.
Purpose of the Study:
- To develop and evaluate a population pharmacokinetic model-based guideline for individualized pegaspargase dosing.
- To compare the effectiveness, adherence, and toxicity of the new guideline against the old guideline.
Main Methods:
- The new guideline involved 1 individualized dose for standard-risk and 14 for medium-risk patients after induction, targeting trough activity levels of 100–250 IU/L.
- Effectiveness, adherence, and toxicity were assessed and compared between the new and old dosing guidelines.
- Data from 92 patients (714 samples) in the new group and 509 patients (4539 samples) in the old group were analyzed.
Main Results:
- The new guideline achieved target trough activity levels in 32% of patients after the first dose, compared to 13% with the old guideline (P < 0.001).
- Fewer dose reductions were needed with the new guideline (median 3 vs. 5 for medium-risk patients; 2 vs. 4 for continuous dosing, P < 0.001).
- Adherence to the new guideline exceeded 99%, and toxicity, including elevated serum alanine transaminase, was comparable or lower than the old guideline.
Conclusions:
- The new pegaspargase dosing guideline simplifies achieving and maintaining target trough activity levels, requiring fewer dose adjustments.
- The guideline's high adherence rate confirms its practicality and ease of integration into clinical practice.
- This model-based approach improves individualized pegaspargase dosing in acute lymphoblastic leukemia treatment.
Background:
In the Dutch Childhood Oncology Group ALL11 protocol, PEGasparaginase dosing was individualized for standard-risk and medium-risk patients with acute lymphoblastic leukemia. After using our pragmatic old guideline, we aimed to improve individualized PEGasparaginase dosing by developing a population pharmacokinetic model-based dosing guideline.
Method:
After the 3 doses of 1500 IU/m 2 administered in induction, standard-risk patients received 1 individualized dose and medium-risk patients 14, targeting trough activity levels between 100 and 250 IU/L. The effectiveness, adherence, and toxicity of our new dosing guideline was assessed and compared with the old guideline.
Results:
In total, 92 patients (714 samples) were included in the new dosing group and 509 patients (4539 samples) were included in the old dosing group. Comparing the effectiveness, we found that 32% (22/67) of patients in the new and 13% (47/354) of patients in the old dosing group were within the target range after the first individualized dose ( P < 0.001). Among medium-risk patients, a median of 3 dose reductions was needed to reach and maintain levels within the target range in the new dosing group compared with 5 in the old dosing group ( P < 0.001). With a continuous PEGasparaginase dosing schedule, target trough activity levels were reached after 2 dose reductions in the new group versus 4 in the old dosing group. The adherence to the new guideline was >99%, with 6/714 recommended doses deviating from the guideline. With exception of a lower proportion of patients with increased (≥grade 3) serum alanine transaminase (34% new vs 64% old, P < 0.05) in the new dosing group, toxicity was comparable between guidelines.
Conclusions:
With the new dosing guideline, fewer dose-reduction steps are necessary to reach and remain within the target. The high adherence rate emphasized its simplicity and practicality, confirming that it can be easily integrated into clinical practice.
