Favorable remission induction rate with twice weekly doses of L-asparaginase.

Two dosage regimens of L-asparaginase were investigated to determine differences in the production of abnormal reactions and remission induction. Patients were randomly assigned to receive 200 i.u./kg daily for 14 days (Regimen A) or 1000 i.u./kg twice weekly for 2 weeks (Regimen B). All were in relapse and refractory to several chemotherapeutic agents. Medianduration of diseasewas 11 months in RegimenA and 16 months in Regimen B. Three out of 16 patients in Regimen A and 7 out of 16 in Regimen B achieved a complete remission. Median duration of unmaintained remission was 33 days in Regimen A and 40 days in Regimen B. Upon relapse, reinduction was attempted in 9 patients at the original dosage. Complete remission was achieved in 1 out of 3 in Regimen A and 1 out of 6 in Regimen B (duration, 31 and 180 days, respectively). Six patients in each regimen experiencedabnormal side effects comprising hypersensitivity reactions (3 in Regimen A and 4 in Regimen B), nausea, vomiting, cough, cyanosis, abdominal pain, and fever. One patient in Regimen A developed hyperglycemia without pancreatitis. The B regimen of L-asparaginase permitted less frequent clinic visits and a favorable remission induction rate without significant increase in toxicity.