Therapy of chronic myeloid leukaemia can benefit from the activation of stem cells: simulation studies of different treatment combinations

BACKGROUND Newly diagnosed patients with chronic myeloid leukaemia (CML) are currently treated with tyrosine kinase inhibitors (TKIs) such as imatinib, nilotinib or dasatinib. However, incomplete eradication of residual disease is a general problem of long-term TKI therapy. Activation of mouse haematopoietic stem cells by interferon-\textgreeka (IFN\textgreeka) stimulated the discussion of whether a combination treatment leads to accelerated eradication of the CML clone. METHODS We base our simulation approach on a mathematical model describing human CML as a competition phenomenon between normal and malignant cells. We amend this model to incorporate the description of IFN\textgreeka activity and simulate different scenarios for potential treatment combinations. RESULTS We demonstrate that the overall sensitivity of CML stem cells to IFN\textgreeka activation is a crucial determinant for the benefit of a potential combination therapy. We furthermore show that pulsed IFN\textgreeka together with continuous TKI administration is the most promising strategy for a combination treatment in which the therapeutic benefit prevails adverse side effects. CONCLUSION Our modelling approach is a highly beneficial tool to quantitatively address the competition between normal and leukaemic haematopoiesis in treated CML patients. We derive testable predictions for different experimental settings that are suggested before the clinical implementation of the combination treatment.