Head-to-head study shows greater efficacy, less toxicity in newly diagnosed patients
In the first head-to-head scientific study of Gleevec and interferon, results show remarkably greater response and less toxicity for Gleevec in patients newly diagnosed with chronic myelogenous leukemia (CML). The study is being presented at the 38th Annual Meeting of the American Society of Clinical Oncology in Orlando, Fla.
"This information will undoubtedly affect how any physician treats patients diagnosed with CML," said Brian Druker, M.D., JELD-WEN Chair of Leukemia Research at Oregon Health & Science University and lead investigator of the study.
CML is one of four common types of leukemia, affecting about 5,000 Americans each year. Before Gleevec was approved by the Food and Drug Administration in May 2001, interferon was regarded as the standard treatment for the disease.
The study tracked 1,106 newly diagnosed CML patients at 177 centers in 16 countries who were either given Gleevec or interferon. After 12 months, approximately 83 percent of the Gleevec patients experienced a major cytogenetic response (meaning a reduction of leukemia cells in their blood), compared with 20 percent of patients on interferon. Approximately 68 percent of the Gleevec patients achieved a complete cytogenetic response (no leukemia cells present) compared with 7 percent of patients on interferon. Also, only about 1 percent of Gleevec patients saw their disease progress, compared with 7 percent of the interferon patients. Finally, less than 1 percent of Gleevec patients were taken off the study due to intolerance, compared with 23 percent of the interferon patients.
"The trouble with interferon is that it is not well tolerated. Patients taking interferon generally feel like they have a bad case of the flu all the time," said Druker. Interferon, a naturally occurring hormone that must be injected by patients each day of treatment, generally keeps the worst symptoms of CML at bay, but is not a cure for most patients. In contrast, Gleevec, a pill taken once a day, has shown few side effects and reduces or eliminates signs of the disease for most CML patients when treated early.
Druker, in collaboration with scientists at Novartis, helped to develop Gleevec to target the molecular cause of CML, an errant protein called Bcr-Abl. Druker performed the laboratory testing of the drug and led the clinical trials. Last year the FDA broke a record for cancer therapy by approving Gleevec for CML patients who failed interferon in less than three months. Earlier this year, the FDA approved Gleevec for treatment of gastrointestinal stromal tumors, a deadly form of intestinal cancer.