CML survival comparable for front-line family donor HSCT, best available drug therapy
medwireNews: A phase III clinical trial has identified several factors that may help physicians decide between tyrosine kinase inhibitors (TKIs) and allogeneic haematopoietic stem cell transplantation (HSCT) for patients with chronic myeloid leukaemia (CML).
The CML-IIIA study investigators suggest in Leukemia that HSCT should be considered for patients with a familial donor as a first- or second-line treatment rather than only as a rescue option.
“Without the expense of early excess mortality, patients with newly diagnosed high-risk CML and non-responders to first-line TKI can benefit from an early low-risk HSCT through improved long-term survival, shorter time of treatment, a higher rate of molecular remissions and lower health-care costs”, they write.
“Our data fit with a recent comparison in the imatinib era.”
The authors report that the 166 patients with newly diagnosed CML with a matched family donor who were randomly assigned to undergo primary HSCT had comparable survival to the 261 patients who were given the best available drug treatment, with 10-year probabilities of 0.76 versus 0.69.
Drug treatment consisted of interferon plus hydroxyurea and cytosine arabinoside in the pre-TKI era, with 84% of patients who did not undergo allogeneic HSCT given imatinib or a second-generation TKI where feasible.
And survival did not differ between the HSCT and best drug treatment groups for the 48 patients who experienced blast crisis, the researchers observe.
However, survival probability was contingent on the patient Euro score for disease risk, and transplant risk, as defined by an adapted European Group for Blood and Marrow Transplantation (EMBT) score.
Patients who underwent HSCT with an adapted EMBT score of 0–1 had a 10-year survival probability of 0.85 and this was significantly higher than the 10-year probabilities for those given best drug treatment who had a high-risk or non-high-risk Euro scores, at 0.41 and 0.73, respectively.
But survival was comparable for HSCT patients with adapted EMBT score of 2 or 3–4, with 10-year probabilities of 0.70 and 0.68, and both the high-risk and non-high risk Euro score patients given drug therapy.
Nevertheless, the HSCT and drug treatment groups were also comparable in terms of Karnofsky score and symptoms, report R Hehlmann (Medizinische Fakultät Mannheim der Universität, Heidelberg, Germany) and co-authors.
In addition, patients who underwent HSCT were significantly more likely to both achieve molecular remission (56 vs 39%) and be free from drug treatment (56 vs 6%) than those given TKIs.
Thus, the investigators suggest that HSCT might be a good alternative to rescue chemotherapy for patients who fail first-line TKI treatment and have a low transplant risk score and a family donor, whereas drug therapy and supportive care would be a better option for patients with advanced disease and a high transplant risk score.
“The overall strategy should involve close cooperation between local physicians, treatment centers and transplant teams”, the researchers believe.
“The concept of donor versus no donor should probably change to a risk-adapted strategy, defined by disease and transplant risk for acquired hematological disorders in general”, they recommend.
medwireNews is an independent medical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2015
Leukemia 2015; Advance online publication