Leukemia cure on the horizon?
Curing leukemia is no longer a dream, especially for leukemia types related to a single known genetic defect, argued Dr. Pia Raanani, Head of Hematology Division at the Rabin Medical Center, Petah Tikva, Israel.
“For instance, treatment of chronic myeloid leukemia [CML], which is caused by a BCR-ABL mutation, has undergone a revolutionary change with the introduction of tyrosine kinase inhibitors such as imatinib, dasatinib and nilotinib. The use of these agents has changed overall survival as well as the quality of life of CML patients,” she said. “Ongoing studies are evaluating a potential cure, defined as absence of long-term leukemia relapse after treatment discontinuation.”
CML patients who had maintained a major or complete molecular response (MMR/CMR) with undetectable BCR-ABL levels for at least 2 years were enrolled in treatment discontinuation studies. “Current data from France, Australia, Japan and Korea suggest that nearly 40 percent of patients remained in remission for up to 4 years without treatment. Although relapse rates ranged from 22 to 39 percent at 1 year to 60 percent at 4 years, we are working on new therapeutic approaches for patients who are in long-term remission to prevent relapse,” noted Raanani. [Blood 2013;122:515-522; ASH 2013 Annual Meeting, abstract 3998]
Cure rates of acute promyelocytic leukemia (APL), which is related to the PML-RARA gene, have also increased considerably with the use of retinoic acid and arsenic trioxide, and more recently some targeted agents.
“Hairy cell leukemia, associated with the BRAF mutation, is another type of leukemia with a good potential for cure using targeted and biological therapies,” she added. “To quote Winston Churchill, ‘this is not the end, not even the beginning of the end. But it is, perhaps, the end of the beginning’ when we look ahead towards cure of those and other leukemias.”