Autologous stem cell transplantation after conditioning with yttrium-90 ibritumomab tiuxetan BEAM in refractory non-Hodgkin diffuse large B-cell lymphoma: results of a prospective, multicenter, phase II clinical trial

We thank Drs. Procházcka and Hlusí for their interest in our paper1 and for their comments. Our study included 31 patients, and 30 received the proposed treatment. The study was designed to evaluate not only the safety and efficacy of the treatment but also, very importantly, its feasibility. For this reason, an intent-to treat design seems to be more appropriate since it provides additional information on the real possibility of applying the treatment to a refractory patient population. However, in our study, only one patient did not proceed to autologous stem cell transplantation (ASCT) due to disease progression. Thus, we believe that the information in the manuscript clearly describes the efficacy of the procedure in this particular study. Patient evaluation after ASCT was performed using PET/CT based on Cheson 2007 criteria,2 as is stated in the manuscript. The statement provided by the authors concerning evaluation of responses is incorrect. As described in the manuscript, detailed information on the response at Day +100 is given for all patients receiving the study treatment: 21 patients responded and the remainder died either from acute toxicity or disease progression. Overall survival (OS) and progression-free survival (PFS) curves were plotted according to Cheson 2007 definitions. However, after reviewing the figures we realized there was an error in the title. Figure 1 should be named “Progression-free survival” and Figure 2 “Overall survival”, respectively. We thank Drs. Procházcka and Hlusí for bringing our attention to this issue, which has now been corrected. Importantly, this does not change the numbers described for survival in the manuscript (OS 63% and PFS 61%, both at 3 years). Finally, our data build upon the value of adding radioimmunotherapy to the conditioning treatment for refractory DLBCL patients as has been shown by others.3 However, as is usually the case for phase II studies, caution should be used in applying this in daily clinical practice until results from randomized trials are available.