A 5-year follow-up of patients with chronic myeloid leukemia ( CML ) who began continuous treatment with Imatinib ( Glivec / Gleevec ) reports that the drug can induce durable hematologic and cytogenetic responses in a high proportion of patients.
When the drug first was developed by Brian J Druker, at the Oregon Health & Science University Cancer Institute, the overall survival rate for patients with chronic myelogenous leukemia taking this new experimental drug was unknown.
" We've completely changed the outlook for patients with this disease. Before Imatinib, patients were fortunate if they lived five years. Now, we've given patients a hopeful future," said Druker, the principal investigator for the study.
Today, after five years, the overall survival of 553 subjects randomized to receive Imatinib as their initial therapy is nearly 90 percent, 95 percent if only deaths related to chronic myelogenous leukemia are considered.
Just 5 percent of subjects discontinued Imatinib because of side effects.
The results are published in the New England Journal of Medicine ( NEJM ).
This study also shows that the risk of relapse has trended downward during the past three years. In the study's fifth year, less than 1 percent of patients progressed from the chronic phase to more advanced phases of the disease.
" This trend, coupled with the low risk of relapse, means that the possibility of long-term survival with chronic myelogenous leukemia is increasingly likely," Druker said.
The five-year study was conducted at 117 centers in 16 countries.
Imatinib is a signal transduction inhibitor that interferes with the enzymes that trigger the growth of cancerous cells.
Imatinib acts on CML cells by inhibiting the disease-causing enzyme BCR-ABL that tells cells to grow and divide.
Imatinib has also been approved for people with advanced gastrointestinal stromal tumors, dermatofibrosarcoma protuberans, Philadelphia chromosome-positive acute lymphoblastic leukemia, certain forms of myeloproliferative disorders, hypereosinophilic syndrome, and aggressive systemic mastocytosis.
Source: Oregon Health & Science University, 2006