17p-CLLAllogeneic HSCT in 17p- CLL in First or Second Partial or Complete Remission at Transplant: a Non-interventional Prospective Study.

Objective: The aim is to determine early PFS after allogeneic HCT in first or second remission of 17p-/p53-mutated CLL within an epidemiologic study. Methods: Neither the decision for allogeneic transplantation nor specific treatment recommendations for patients with 17p-/p53-mutated CLL are part of the study. Instead, the study protocol refers to EBMT guidelines. Indications for allogeneic stem cell transplantation in chronic lymphocytic leukemia: the EBMT transplant consensus. Leukemia 21, 2007, 12-17). Minimal essential data (MED) A and B, defined by the EBMT, will be collected (www.ebmt.org). The rate of progression-free survival (PFS) at 1 year after HSCT was selected as primary endpoint. Death, clinical relapse or progression but not immune manipulations (taper of immunosuppression, DLI, rituximab) are considered as treatment failure for PFS. Patients without information on one-year follow up will be considered as having experienced treatment failure. The rate of PFS at 1 year will be calculated by dividing the number of patients without treatment failure by the number of patients who met all selection criteria. For the calculation of the sample size a fixed sample design was selected. The null hypothesis is that the success-rate for PFS is equal or less than 50%. Referring to the retrospective EBMT survey, PFS at one year after allogeneic HCT is expected to be 70%. According to Fleming-A'Hern (1982) the null hypothesis can be rejected with a power of 80% and an alpha error of 5% if a minimum of 24 out of 37 informative patients did not experience treatment failure during the first year after allogeneic HCT (Machin et al, Sample Size Tables for Clinical Studies, Wiley-Blackwell, 3rd edition, 2009). Taking into account a 10% drop-out rate by violation of inclusion criteria the target number of patients to be included was set at 41 patients.