MIAMI BEACHLong-term follow-up of 23 patients with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) in first complete remission showed a relatively low relapse rate at 3 years when treated with allogeneic bone marrow transplant from HLA-matched siblings, D.S. Snyder, MD, reported at the American Society of Hematology (ASH) annual meeting.
Being positive for the Philadelphia chromosome is an extremely poor-risk factor for pediatric and adult ALL patients, said Dr. Snyder, of the City of Hope National Medical Center, Duarte, California.
In this study, from City of Hope and Stanford University, patients were treated between 1984 and 1997. All patients but one were conditioned with fractionated total body irradiation (TBI) (1,320 cGy) and high-dose etoposide(Drug information on etoposide) (60 mg/kg). One patient received high-dose cyclophosphamide(Drug information on cyclophosphamide) instead of etoposide, and another patient received both drugs.
Nine patients died following transplanttwo from relapsed leukemia and seven from transplant-related causes. The 3-year probabilities of disease-free survival and relapse were 65% and 12%, respectively. The 3-year probabilities for patients who were transplanted after 1992 were 81% and 11%, respectively.
The study did not show any differ-ences in risks of relapse or disease-free survival based on the expression of p190 vs p210 bcr-abl oncogene, Dr. Snyder said, and the relatively low relapse rate may reflect enhanced antileukemic activity of etoposide/TBI, compared to cyclophosphamide-based regimens.
He noted that the favorable disease-free survival for patients transplanted after 1992 may be explained by improvements in supportive care, specifically the prevention and treatment of fungal and cytomegalovirus (CMV) infections.