Response: Drug treatment and allografting as first-line therapy in young patients with CML

Thanks for your comment on our report.¹  Indeed, there is no rule without exceptions. We agree and have already stated in our report that patients' preference, very low transplantation risk, and economic reasons may be possible exceptions.

Transplantation-related mortality and years lost due to transplantation weigh heavily also in very young patients. Published data do not support the notion that this patient group has a lower risk of transplantation-related mortality. Early mortality rates for chronic phase children in recent series range around 20%.^2,–4  In addition, the 14 patients younger than 20 years in our study provide no evidence that these patients are different from the rest of the study population (1 each of 5 transplanted and of 9 drug-treated patients died). A definite cure by allografting is not supported by long-term observations, which report a relapse rate of 1% per year.⁵  Although allografting has improved in recent years due to better patient selection, better HLA-typing, better donor availability, and better supportive care, drug treatment has also improved to a 5-year survival rate of 89% under imatinib with no serious late toxicities observed thus far.⁶  Considering the development of even more efficacious drugs, the prospects of long-term survival with modern drug treatment have to be weighed against early mortality after allografting. Allografting has to be discussed after imatinib failure or suboptimal response.

At present, there is no indication that the years of life lost due to transplantation are compensated later on. The prospects of allografting also in young patients will depend on how much early mortality is accepted by patients in the face of alternative treatments with potentially better long-term perspectives.