The US Food and Drug Administration has accepted Enzon Pharmaceutical Inc.’s supplemental biologics license application (sBLA) seeking approval for an expanded label for its paediatric oncology product, Oncaspar, as a first-line therapy for the treatment of patients with acute lymphoblastic leukaemia (ALL).

Currently, Oncaspar is indicated for patients with ALL who require L-asparaginase in their treatment regimen, but have developed hypersensitivity to the native forms of L-asparaginase. The company anticipates that the FDA will take action on the sBLA during the third quarter of 2006, states an Enzon release.

"Today's announcement further demonstrates our renewed commitment to optimising the potential of our marketed products and to children stricken with cancer. Oncaspar is an important drug today in the treatment of paediatric ALL and we believe this filing supports a greater role for this therapy. We look forward to working closely with the FDA throughout this review process and making the therapeutic advantages of Oncaspar available as a first-line treatment for ALL patients," said Jeffrey H. Buchalter, Enzon's chairman and chief executive officer

Enzon is supporting its application for this expanded indication based on data from two randomised studies conducted by the Children's Cancer Group (CCG), CCG-1962 and CCG-1991, with safety data from more than 2,000 patients.

CCG-1962 is a randomised controlled study comparing Oncaspar versus native L-asparaginase (Elspar) for the first-line treatment of paediatric ALL patients. The observed advantages of Oncaspar versus native L-asparaginase in CCG-1962 included a lower incidence of neutralising antibodies, more rapid clearance of lymphoblasts from the bone marrow, and a more convenient dosing schedule. Enzon is using the data from CCG-1962 to support its sBLA for Oncaspar with efficacy data from 118 patients, added the release.

Oncaspar is a PEG-enhanced version of the naturally occurring enzyme L-asparaginase. L-asparaginase is an enzyme that depletes the amino acid asparagine, which certain leukaemic cells are dependent upon for survival. Oncaspar was granted a marketing license by the US Food and Drug Administration in February 1994 to treat patients with acute lymphoblastic leukaemia who require L-asparaginase in their treatment regimen, but have developed hypersensitivity to native forms of L-asparaginase.

Enzon Pharmaceuticals Inc. is a biopharmaceutical company dedicated to the development and commercialisation of therapeutics to treat patients with cancer and other life-threatening diseases.