Children and adolescents could benefit from unrelated donor stem cell transplantation

The Institute for Quality and Efficiency in Health Care (IQWiG) has informed the Federal Joint Committee about new study results on the potential benefit of unrelated donor stem cell transplantation in patients with acquired severe aplastic anaemia. These results could change the conclusion of an IQWiG final report already presented in April 2007. The Institute evaluated this study, which was conducted in Japan and has only recently become available, and published its findings in the form of a working paper on 19 February 2008. This study is so far the only prospective study with a control group: it compared a total of 52 patients under the age of 18, with severe or very severe aplastic anaemia, who had failed to respond to an initial course of immunosuppressive therapy (IST). Subsequently, 31 of these patients underwent unrelated donor stem cell transplantation. The remaining 21 patients, who lacked suitable donors, received a second course of IST.

Only about 10% of patients responded to repeated IST

Regarding the primary endpoint of the study, "failure free survival”, the authors reported almost dramatic differences: whereas only 9.5% of patients receiving repeated IST responded fully or partially to therapy within 6 months according to the definition in the study, this was achieved by 83.9% of the transplanted patients, without disease recurrence or the death of patients. However, the difference in the overall number of survivors over a period of 5 years was only marginal (IST: 95.2%; transplantation: 93.5%).

In the opinion of IQWiG, the certainty of results in the study is limited, among other things, by the fact that the treatment groups were not fully comparable and differed regarding gender and disease severity. Nevertheless, the Institute now classifies the relevance of unrelated donor transplantation differently and now sees indications of an (additional) benefit compared with a second course of IST, at least in children and adolescents.

In April 2007, on the basis of the study data available up to this time point, IQWiG had come to the conclusion that a reliable evaluation of unrelated donor stem cell transplantation was not possible, as robust data were lacking. In the final report, the Institute had already referred to the Japanese study that they have now evaluated. However, the study could not be considered at that time, because it had not been fully published and could not be interpreted with sufficient certainty.

Contact: +49 (0) 221-35685 0; E-mail: info@iqwig.de