NEW ORLEANS—A modified form of erythropoietin(Drug information on erythropoietin) (epoetin alfa, EPO) may allow for less frequent dosing in anemic cancer patients than currently available forms of the drug.
The drug, novel erythropoiesis stimulating protein (NESP), has a significantly longer half-life than recombinant human EPO (rHuEPO). It has already been shown to have a two- to threefold longer half-life when used in patients with chronic renal failure.
That longer half-life provides similar benefits for cancer patients, said John Glaspy, MD, associate professor of medicine, University of California, Los Angeles (UCLA) School of Medicine, and medical director, Bowyer Surgical Oncology Center.
Dr. Glaspy presented the results of a phase I/II study of the new agent at the 36th Annual Meeting of the American Society of Clinical Oncology (ASCO).
Half-life of More Than 40 Hours
“The results suggest we will have an EPO agent that can be dosed over 2 or 3 weeks for cancer patients.” Dr. Glaspy said. In chronic renal failure patients, EPO has a half-life of about 18 hours, compared with more than 40 hours for NESP.
Dr. Glaspy noted that NESP was designed by modifying the primary sequence of EPO to increase the carbohydrate content, which affects its half-life. Phase III studies in patients with chronic renal failure proved that the agent maintains hemoglobin levels with doses given as infrequently as once every 2 to 3 weeks.
Dr. Glaspy presented results of a randomized, open-label, dose-escalation study of NESP in patients with nonmye-loid malignancies and anemia secondary to multiple cycles of chemotherapy. The cancer patients were randomized to receive either NESP or rHuEPO.
NESP was given in doses of 0.5, 1.0, 1.5, 2.25 or 4.5 µg/kg administered subcutaneously once weekly for 12 weeks. NESP treatment was initiated on day 1 of the first cycle of chemotherapy. Recombinant human EPO was administered subcutaneously at standard doses of 150 U/kg three times weekly, also for 12 weeks.
At the end of 12 weeks, the mean half-life for NESP among 96 patients ranged from 37.2 to 42.2 hours from the lowest to the highest doses, respectively. The half-life for the various doses was similar to those found in studies among chronic renal failure patients, Dr. Glaspy pointed out. Analysis of data from patients receiving rHuEPO was not yet complete.
While the findings are preliminary, they suggest that oncologists will soon have an agent that can be administered less frequently, Dr. Glaspy said. “I think you might be able to give this every 3 weeks, depending on the patient,” he noted.
