L-Asparaginase (L-ASP) Related Toxicities with Asparaginase Erwinia Chrysanthemi in a Large Compassionate Use Protocol.

L-asparaginase (L-ASP) is an important component of multi-agent chemotherapy for treatment of Acute Lymphoblastic Leukemia (ALL) in children and young adults. The pegylated E. coli derived form, Oncaspar^® (PEG-ASP), is most commonly used because of its longer half-life and lower immunogenicity compared to the native enzyme; however, clinical hypersensitivity reactions still occurs in 10–30% of patients (pts) requiring its discontinuation. Asparaginase Erwinia Chrysanthemi (Erwinaze™) is an L-ASP derived from a different bacterium and is immunologically distinct from the E. coli L-ASP. We conducted a compassionate use trial of Erwinaze in pts with ALL and hypersensitivity to native E. coli or PEG-ASP to collect safety information.

Pts of any age with ALL or lymphoblastic lymphoma (LBL) who developed a Grade ≥2 clinical hypersensitivity reaction to PEG-ASP or native E. coli ASP (Elspar^®) were eligible. Pts with a history of pancreatitis, previous allergic reaction to Erwinaze, or pregnant, were excluded. The study was IRB approved at each institution and pts/family provided informed consent/assent. Safety information on Erwinaze-related adverse events (AEs) were captured on Case Report Forms (CRFs) submitted to the Sponsor when the pt completed his/her entire Erwinaze treatment plan. AEs may have also been reported directly by the investigational sites.

Between February 2006 and November 2011, 1,368 pts were treated with Erwinaze. CRFs were received in 893 pts and 47 additional AEs were received from patients for which a CRF was not obtained. The average age was 9.6 years (range 1–66). The majority of patients (63.5%) were male. Of the pts for which CRFs were received (893); 77.6% were able to conclude their Erwinaze treatment. Discontinuation was due to allergic reaction in 8.8%; other AEs 4.7%; at the physician or patient discretion 7.5%; and missing information in 1.3%. Anaphylaxis was reported in 8 pts (0.9%) and Grade ≥2 clinical hypersensitivity reactions in 130 (13.8%). The incidence of pancreatitis was 3.9%, hemorrhagic or thrombosis abnormalities 2.4%, hyperglycemia 3.6% and elevation in liver enzymes 3.5%. There were 18 deaths on study; 11 disease progression, 3 intracranial hemorrhage, 4 other individual reports.

This is the largest study of pts treated with Erwinaze to determine the toxicity profile. Erwinaze was well tolerated with no unexpected toxicities identified beyond those associated with L-Asp treatment. This compassionate use trial permitted the continuation and completion of asparaginase treatment in 77.6% of pts with hypersensitivity reactions to E. coli formulations. Final results will be available for presentation.

Plourde:Jazz Pharmaceuticals: Employment, Equity Ownership. Mercedes:Jazz Pharmaceuticals: Employment. Corn:EUSA Pharma: Employment.