Substituting pegaspargase with recombinant Erwinia asparaginase after hypersensitivity reactions: case series of Canadian adult patients with acute lymphoblastic leukemia.

Asparaginase treatment for acute lymphoblastic leukemia/lymphoblastic lymphoma is often discontinued or interrupted due to hypersensitivity reactions (HSRs) or silent inactivation, with inferior clinical outcomes. In those instances, consensus experts recommend switching to an immunogenically distinct asparaginase preparation. This case series details experiences of 4 adult patients who developed HSRs or silent inactivation while receiving modified Dana-Farber Cancer Institute (DFCI) protocols involving pegaspargase and consequently switched to crisantaspase (JZP458), a recombinant Erwinia asparaginase that was well tolerated without evidence of cross-immunological activity in 3 out of 4 cases, and with achievement of adequate serum asparaginase levels. Although limited to 4 patient cases, these data suggest that switching to crisantaspase after HSRs or silent inactivation of pegaspargase may represent a viable therapeutic option in adults, with close monitoring to ensure effective asparaginase levels. Dedicated clinical studies are needed to examine DFCI lymphoblastic leukemia protocols in more diverse patient populations.