 Using the data of the PBSCT group in the former European mantle cell study as baseline in a proportional hazard model, the improvement for the time to treatment failure expected by the new strategy can be expressed by reduction of relative risk rr. A risk reduction to 52 which would correspond to a improvement of 20 in failure free survival after 3 years seems to be a clinical relevant improvement. For a working significance level alpha0.05 and a power of 95 the number of events necessary for a one sided fixed sample trial is about 105. During this study the time to treatment failure will be monitored using an equivalent one-sided triangular sequential test. 