Posttransplantation Treatment BCR/ABL transcript levels have served as early predictors for hematologic relapse following transplantation. These should facilitate risk-adapted approaches with immunosuppression or TK inhibitor(s), or a combination of the two. Donor leukocyte infusions (without any preparative chemotherapy or GVHD prophylaxis) can induce hematologic and cytogenetic remissions in patients with CML who have relapsed after allogeneic SCT. Imatinib can control CML that has recurred after allogeneic SCT but is sometimes associated with myelosuppression and recurrence of severe GVHD. Imatinib after allogeneic SCT is being studied for prevention of relapse in patients with advanced disease at the time of transplantation (., patients at high. | Chapter 104. Acute and Chronic Myeloid Leukemia Part 15 Posttransplantation Treatment BCR ABL transcript levels have served as early predictors for hematologic relapse following transplantation. These should facilitate risk-adapted approaches with immunosuppression or TK inhibitor s or a combination of the two. Donor leukocyte infusions without any preparative chemotherapy or GVHD prophylaxis can induce hematologic and cytogenetic remissions in patients with CML who have relapsed after allogeneic SCT. Imatinib can control CML that has recurred after allogeneic SCT but is sometimes associated with myelosuppression and recurrence of severe GVHD. Imatinib after allogeneic SCT is being studied for prevention of relapse in patients with advanced disease at the time of transplantation . patients at high risk for relapse patients undergoing reduced-intensity transplants or patients with slow reduction of BCR ABL message following transplantation. Imatinib has also been combined with donor lymphocytes to induce rapid molecular remissions in CML patients with disease relapse after allogeneic SCT. Of interest are studies with newer TK inhibitors following transplantation for imatinib-resistant CML. Imatinib Mesylate Imatinib mesylate Gleevec functions through competitive inhibition at the ATP binding site of the Abl kinase in the inactive conformation which leads to inhibition of tyrosine phosphorylation of proteins involved in Bcr Abl signal transduction. It shows specificity for Bcr Abl the receptor for platelet-derived growth factor and Kit tyrosine kinases. Imatinib induces apoptosis in cells expressing Bcr Abl. In newly diagnosed CML imatinib 400 mg d is more effective than IFN-a and cytarabine. The complete hematologic remission rate at 18 months of patients treated with imatinib was 97 compared to 69 in patients treated with IFN-a and cytarabine. Similarly the complete cytogenetic remission rate was 76 with imatinib compared to 14 with IFN-a and cytarabine. All .
