Phase-III study on the value of allogeneic stem cell transplantation in poor-risk chronic lymphocytic leukemia (GCLLSG/GCTSG CLL-X2 trial)

• Applicant: Professor Dr. Peter Dreger
• Subject Area: Hematology, Oncology
• Term: from 2008 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 43618699

Patients with high- or very high-risk chronic lymphocytic leukemia (CLL) face a dismal prognosis. Although conventional (immuno-)chemotherapy can induce responses, the majority of patients will die from their disease within few years. Allogeneic stem cell transplantation (allo-SCT) has been shown to provide long-term disease control and possibly cure in selected patients with CLL. However, due to the lack of controlled trials, the clinical value of allo-SCT for the treatment of CLL is largely unclear. In this trial, we will study the benefit of allo-SCT for patients with unfavourable CLL using a risk-stratified randomized phase-III study design: Patients with an HLA-identical donor who have relapsed between 6 and 24 months after intensive therapy (=high-risk, Stratum 1) will be truly randomized to receive chemotherapy or allo-SCT consolidation after having responded to 3 cycles of appropriate salvage chemotherapy. Patients with purine-analogue-refractory disease (=very high-risk, Stratum 2) will be biologically randomized by donor availability between non-transplant and allo-SCT consolidation. Primary endpoint is 2-year eventfree survival, which is expected to be improved by 30% with allo-SCT in both strata. The trial will include 145 patients in Stratum 1, and 106 patients in Stratum 2. Based on trial conduct within the German CLL Study Group and the German Cooperative Transplant Study Group, this approach offers the unique opportunity to investigate if allo-SCT could change the unfavourable natural course of poor-risk CLL.

• DFG Programme: Clinical Trials