Patient 2:
Patient 2 is a 17-year-old male with T-cell ALL. During his third dose of pegaspargase, he had a grade 3 hypersensitivity reaction. An asparaginase activity panel was drawn 7 days after the dose, and he had undetectable asparaginase activity with anti-asparaginase antibodies present. He clinically tolerated a pegaspargase desensitization, but like patient 1, was unable to regain sufficient asparaginase activity. For every dose of pegaspargase, 6 doses of recombinant Erwinia asparaginase 40 mg (25 mg/m2) IM every 48 hours was substituted.11
Due to complaints of nausea during and after receiving his recombinant Erwinia asparaginase injections, an ammonia level was obtained prior to the second dose of the fifth and final course and was found to be 325 µmol/L (ULN 30 µmol/L). He was also initiated on lactulose 20 grams by mouth 4 times daily titrated to three soft stools per day. He reported improvement of symptoms after initiation of lactulose, and subsequent ammonia decreased to 136 µmol/L. An NSAA was measured before dose five and was markedly elevated at 0.84 IU/mL, however this level was not resulted in time to modify his final remaining dose.