[Comparison of polyethylene glycol conjugated asparaginase and L-asparaginase for treatment of childhood acute lymphoblastic leukemia].

OBJECTIVE

To evaluate efficacy and side-effect of polyethylene glycol conjugated asparaginase (PEG-Asp) containing VDPAP regimen in newly diagnosed childhood acute lymphoblastic leukemia (ALL).

METHODS

One hundred and thirty five children with newly diagnosed ALL were randomized assignments to receive PEG-Asp containing VDPAP regimen or L-asparaginase containing VDLP regimen as control for induction therapy. The VDPAP regimen consisted of daunomycin on day 1, 2, prednisone for 28 days, vincristine once a week for 4 weeks, and PEG-Asp(2500 IU/m2) intramuscularly once every two weeks for 4 weeks. In the VDLP regimen, the PEG-Asp was substituted by L-asparaginase (6000 IU/m2, three times a week for 2 weeks). The pharmacokinetics of PEG-Asp was investigated in 11 patients in VDPAP group.

RESULTS

The complete remission (CR) rates were 84.6% and 89.4%, total response rates were 92.3% and 93.9% (P < 0.05, respectively), and the incidence of adverse effects was 95.6% and 98.5% (P > 0.05) in the VDPAP and VDLP group, respectively. The major adverse effect was allergic response (4.4% and 5.9% in the VDPAP and VDLP group, respectively) and others included coagulopathy and gastrointestinal symptoms. Pharmacokinetics showed that the half-life of PEG-Asp was (170 +/- 45) hours [about (7 +/- 2) days], the serum PEG-Asp activity levels > 0.1 IU/ml throughout induction.

CONCLUSION

The effectiveness of PEG-Asp and L-asparaginase for treatment of pediatric ALL is similar and no difference in adverse effect. The advantage of PEG-Asp is more prolonged effect and convenient.