Reduced-intensity conditioning safe with stem cell transplant in CML

December 10, 2007

NEW YORK (Reuters Health) - A reduction in intensity of the conditioning regimen prior to hematopoietic stem cell transplantation does not significantly reduce overall survival and allows adequate disease control in chronic myelogenous leukemia (CML), researchers report in the November 1st issue of Blood.

Nevertheless, Dr. Partow Kebriaei and colleagues at the University of Texas M. D. Anderson Cancer Center in Houston point out that their study results underscore the need for alternative treatment strategies for CML patients with advanced disease.

The investigators evaluated outcomes of 64 CML patients with advanced-phase disease not eligible for intensive myeloablative conditioning therapy due to older age or comorbid conditions.

Stem cell donor type was matched/related in 30 patients and matched/unrelated in 30 patients. Four patients were mismatched related. All patients were treated with fludarabine-based reduced-intensity conditioning regimens prior to hematopoietic stem cell transplantation.

Median follow-up was seven years. At five years, overall survival was 33% and progression-free survival was 20%, Dr. Kebriaei's team reports.

Incidence of treatment-related mortality was 33% at 100 days, 39% at 2 years and 48% at 5 years after stem cell transplantation.

Disease stage at the time of transplant was the only significant predictor for both overall survival and progression-free survival.

"Reduced-intensity conditioning hematopoietic stem cell transplantation provides adequate disease control in chronic phase CML patients, but alternative treatment strategies need to be explored in patients with advanced disease," the authors conclude. "Treatment-related mortality rates are acceptable in this high-risk population but increase over time."

Dr. Kebriaei's group suggests that "incorporation of tyrosine kinase inhibitors into therapy may downstage patients prior to hematopoietic stem cell transplantation, and their use as maintenance following ...transplantation may help to prevent relapse."