View clinical trials related to BCR-ABL Positive.
Filter by:Patients newly diagnosed with chronic phase chronic myeloid leukemia undergo treatment with TK inhibitors (TKI). A possible cause of TK failure is represented by the insufficient recovery of normal Ph- hematopoiesis during TKI treatment, with consequent severe cytopenias that limit TKI adequate administration. Although rare, this event happens in a proportion of 4-5% of CML patients. Our hypothesis is to circumvent this peculiar condition by providing a normal hematopoiesis from a HLA-matched donor (Human Leukocyte Antigen). The transplant procedure is therefore intended in providing a sustained hematopoiesis that will allow an early treatment with an adequate dosing of TKI. The transplant procedure planned in our study is built on all available evidences to provide the lowest incidence of acute and chronic GvHD (Graft-versus-host disease). Therefore, a bone marrow will be the preferential source and a GvHD prophylaxis based on Anti-thrombocyte globulin (ATG) and Cyclosporine/Methotrexate will be used according to standard current experience in the field of family and unrelated donors. The pre-transplant TKI will be continued until aplasia will develop, in order to decrease the tumor load as much as possible.The use of TKIs shortly after transplant carries the risk of inhibiting the newly transplanted hematopoietic cells, as Kit, an important kinase in normal bone marrow cells, is frequently blocked by Abl inhibitors. The use of bosutinib as post-transplant therapy is justified by the lack of Kit inhibition that distinguishes bosutinib from all other TKIs, and which could allow a minimal inhibitory activity against the transplanted normal bone marrow.
Drug resistance resulting from emergence of Imatinib-resistant BCR-ABL clones is a significant problem in Ph positive ALL patients because after a very good initial response to one TKI inhibitor, many patients relapse within one year, relapse being almost always associated with a BCR-ABL kinase domain point mutation. The patients who relapse after treatment with one TKI can be rescued to remission with another TKI, but the second remission is usually shorter than the previous one. A more potent TKI inhibitor, and pan-active not only on all the BCR-ABL variants (including the second generation TKI resistant T315I mutant), but also on others molecular targets can do better. In this context, Ponatinib is a novel synthetic orally active tyrosine kinase inhibitor (TKI), specifically developed to inhibit BCR-ABL, the fusion protein that is the product of the Philadelphia chromosome (Ph) in chronic myeloid leukemia (CML) and in a subset of acute lymphoblastic leukemia (Ph+ ALL). It potently inhibits the BCR-ABL protein as well as mutated forms of the protein that arise in patients resistant to prior therapies with TKIs. Ponatinib has been demonstrated to inhibit all the mutations that have been detected so far, in vitro and in vivo and to uniformly suppress the emerge of single-mutant clones in a mutagenesis assay. In the Phase II study, 41% of Philadelphia chromosome positive acute lymphoblastic leukemia patients treated with Ponatinib achieved major hematologic response, 47% had a major cytogenetic response, 38% obtained a complete cytogenetic response, showing that Ponatinib provides significant benefit despite previous intolerance or refractoriness to other TKIs. The Phase I trial showed that patients with a more recent diagnosis had increased rates of major molecular response: 79% for 14 patients with 0 to 5 years since diagnosis vs. 29% for 14 patients with more than 5 to 9 years since diagnosis (P=0.02) and 27% for 15 patients with more than 9 to 24 years since diagnosis (P=0.009). These characteristics support the hypothesis for a role of Ponatinib not only in patients resistant to prior TKI therapy but also in untreated ALL Ph+ patients, in order to prevent the emergence of resistant caused by the selection of mutated Ph+ clones and in order to avoid rapid progression of the disease.