“…18 This cut-off of ≥ 0.1 IU/mL has been confirmed and used in many clinical trials. 9,19,[22][23][24] The question arises whether a lower threshold, for example of 0.05 IU/mL, also leads to complete asparagine depletion. Rizzari and colleagues showed that trough asparaginase activity levels of < 0.05 IU/mL, obtained either with native E. Coli or Erwinia asparaginase, resulted in serum and CSF asparagine depletion in children with ALL.…”