The US Food and Drug Administration (FDA) has approved Rylaze® (asparaginase erwinia chrysanthemi [recombinant]-rywn) to be administered on a Monday/Wednesday/Friday (MWF) intramuscular (IM) dosing schedule, in addition to a previously approved dosing regimen (25 mg/m2 IM every 48 hours).

Rylaze is indicated for use as part of a multi-agent chemotherapeutic regimen for the treatment of acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LBL) in adult and pediatric patients 1 month of age and older who have developed hypersensitivity to E. coli-derived asparaginase.

The MWF dosing option was approved under the Real-Time Oncology Review pilot program based on pharmacokinetic data from the IM administration portion of a phase 2/3 study (AALL1931; Identifier: NCT04145531). The trial was designed to assess the tolerability and efficacy of Rylaze at various dosages and routes of administration.

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Findings demonstrated a positive benefit-to-risk profile for a dosing regimen of 25 mg/m2 IM on Monday morning and Wednesday morning, and 50 mg/m2 on Friday afternoon. Efficacy was defined as achievement and maintenance of nadir serum asparaginase activity (NSAA) above the level of 0.1 U/mL by simulation in a virtual population. The analysis showed that more than 90% of patients achieved NSAA of at least 0.1 U/mL by simulation.

The safety profile of Rylaze was consistent with that observed for patients with ALL/LBL who receive asparaginase with chemotherapy (eg, neutropenia, anemia, or thrombocytopenia). There were no new safety signals observed.


  1. Jazz Pharmaceuticals announces US FDA approval of Monday/Wednesday/Friday intramuscular dosing schedule for Rylaze® (asparaginase erwinia chrysanthemi (recombinant)-rywn). News release. Jazz Pharmaceuticals. Accessed November 18, 2022.
  2. Maese LD, Loh ML, Choi MR, et al. Efficacy and safety of intramuscular (IM) recombinant Erwinia asparaginase in acute lymphoblastic leukemia (ALL) or lymphoblastic lymphoma (LBL): The Children’s Oncology Group (COG) AALL1931 study. Published online June 2, 2022. Journal of Clinical Oncology. doi:10.1200/JCO.2022.40.16_suppl.7001
  3. Rylaze. Package insert. Jazz Pharmaceuticals; 2022. Accessed November 18, 2022.

This article originally appeared on MPR