DC Vaccination in CML

The aim of this phase I/II trial is induction of anti leukemic T cell immunity in a clinical situation of "minimal residual disease". This might be a strategy to immunologically eradicate the residual leukemia cells. Patients to be included are chronic phase bcr/abl+ CML (chronic myeloid leukemia) patients in stable cytogenetic and/or molecular remission. These patients can be included if they have: 1. not achieved a CMR (complete molecular response) or 2. achieved bcr/abl \< 10% on qPCR (quantitative polymerase chain reaction) (=MCyR) (Major cytogenic Response), but less than a CCyR (complete cytogenic Response). Autologous DC (Dendritic cells), generated under GMP (Good manufacturing conditions) conditions, are used as a vaccine. These DC constitutively express all putative tumor antigens. In order to ensure sufficient presentation of distinct CML-related antigens, particularly in good responders to TKIs, DC are additionally pulsed with peptides from bcr/abl, WT-1 (Wilms Tumor Protein) and proteinase-3. Monitoring of T cell reactivity against these peptides can then serve as surrogate marker for anti leukemic immunity induced by the vaccine. Vaccination is performed with 10\^7 DC i.d. (intra dermal) in weeks 1, 3, 5, 8, 11, 14, 17, 20, 23 and 26. KLH (keyhole limpet hemocyanin) is used as an adjuvant for vaccine preparations in weeks 3, 5 and 8 (and 11).