February 22, 2012
CTI has been involved in managing an Expanded Access Program for Voraxaze® (glucarpidase), for which BTG International Inc. recently received US Food and Drug Administration regulatory approval.
The program provided emergency use of glucarpidase within 24 hours for patients with methotrexate toxicity and impaired renal function under a treatment protocol. CTI has provided 24/7 coverage, managing more than 165 oncology sites in the US, and shipping drug for more than 115 patients. More than 30 team members were involved in this critical program and ensured that patients were able to receive this emergency treatment as rapidly as possible. Leading the Medical Management of the program, Dr. William Aronstein explained the pharmacology of the drug and the requisitioning process to many pharmacists and oncologists, sharing the available data, discussing the mechanism of action, and exploring treatment options for the patients. CTI also supported BTG during preparation of the Biologics License Application (BLA) for Voraxaze.
Voraxaze is indicated for the treatment of toxic plasma methotrexate concentrations (>1 micromole per liter) in patients with delayed methotrexate clearance due to impaired renal function. It works by cleaving methotrexate into inactive metabolites, thereby (according to the product information) reducing methotrexate levels ≥97% in as little as 15 minutes after intravenous administration. Voraxaze is the first and only drug that directly reduces toxic plasma methotrexate levels.
High dose methotrexate chemotherapy is used in the treatment of cancers including osteosarcoma, leukemia and lymphoma. Despite expert management, some patients receiving high dose methotrexate have impaired renal elimination of the drug; when toxic levels of methotrexate accumulate, they are at risk for complications that include lowered blood counts and mucositis.
The FDA approval was granted under priority review and is based on data from 290 patients (1 month to 85 years of age) treated in 2 single-arm, open label, multicenter trials. Efficacy was established on the basis of the pharmacodynamic endpoint of a rapid and sustained clinically important reduction (RSCIR) in plasma methotrexate concentration (≤1µmol/L within 15 minutes following glucarpidase administration and sustained for up to 8 days) in a subset of 22 treatment-evaluable patients in one of the two clinical studies. Ten of the 22 patients (45%) achieved RSCIR. Moreover, all evaluable patients showed a sustained, greater than 95% reduction in pre-treatment baseline methotrexate concentrations.
Executive Vice President and President, Consulting Services, Lynn Fallon, commented on the Expanded Access Program, stating ”This was an incredible opportunity for CTI to partner with BTG on this important program. Our team worked around the clock, weekends and holidays, sometimes even driving the drug shipment to the airport tarmac in order to reach patients in a timely fashion. CTI was able to help BTG provide use of a promising drug that was still under regulatory review and assist in preparation of the BLA. Congratulations to BTG!”