The U.S. Food and Drug Administration (FDA) has approved Rylaze [asparaginase erwinia chrysanthemi (recombinant)-rywn)] as a component of chemotherapy for patients with acute lymphoblastic leukemia and lymphoblastic lymphoma who are allergic to the E. coli-derived asaparaginase products that are most commonly used for treatment.

One component of the chemotherapy regimen for these blood cancers is the enzyme asparaginase. However, it is estimated that 20% of patients are allergic to the standard E. coli-derived asparaginase.

The FDA approval of Rylaze is based on positive data from an ongoing phase 2/3 single-arm, open-label, multicenter, dose confirmation study evaluating pediatric and adult patients with ALL or lymphoblastic lymphoma who are allergic to E. coli-derived asparaginases. The study is being conducted in two parts. The first part is investigating the intramuscular (IM) route of administration, including a Monday-Wednesday-Friday dosing schedule. The second part remains active to further confirm the dose and schedule for the intravenous (IV) route of administration. The FDA approval of Rylaze was based on data from the first of three IM cohorts, which maintained nadir serum asparaginase activity (NSAA) greater than 0.1 U/mL at 48 hours using IM doses 25 mg/m2. The results of modeling and simulations showed that for a dosage of 25 mg/m2 IM every 48 hours, the proportion of patients maintaining NSAA ≥ 0.1 U/mL at 48 hours would be 93.6%.

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