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.