Background: Pegylated asparaginase (P-Asp) though integral to acute lymphoblastic leukemia (ALL) therapy is often not accessible to patients in developing countries. We share our clinical experience with generic P-Asp along with monitoring of asparaginase activity.
Methods: In this prospective observational study, patients ≤18 years of age with ALL were assigned to receive either generic P-Asp or native asparaginase (N-Asp) in a non-randomized manner. Treatment protocol was based on ALL BFM-95 backbone. The dose of P-Asp was 1500 IU/m2 by intravenous route during induction (Ia) and re-induction (IIa) phase of therapy.
Results: N-Asp or P-Asp was administered to 52 and 54 of the 106 eligible patients respectively. Demographic and disease characteristics were comparable in both arms. The mean trough levels for N-Asp and P-Asp were 156.87 ± 22.35 IU/L and 216.03 ± 73.40 IU/L, respectively (p value <0.001) and all patients achieved therapeutic levels during Ia. Incidence of asparaginase-attributable toxicity was similar in the two arms in both phases of treatment, although hospitalization due to noninfectious causes was more common in P-Asp arm during Ia (13% versus 0%, p value, 0.01). Clinical hypersensitivity and silent inactivation were not observed during Ia while these occurred in 13% and 5% of patients in the N-Asp arm and P-Asp arms of IIa, respectively. The 2-year event free survival for P-Asp and N-Asp groups was 84% and 80.7%, respectively (p value 0.85).
Conclusion: Generic P-Asp was observed to be efficacious and well tolerated in our patients and adequate therapeutic levels were sustained for 2 weeks.
Keywords: Asparaginase; acute lymphoblastic leukemia; children; hypersensitivity; pegylated.