Mobilisation of haemopoietic progenitors in CML: a second course of intensive chemotherapy does not improve Ph-negativity in stem cell harvests

Chronic myeloid leukemia in the Netherlands: a population-based study on incidence, treatment, and survival in 3585 patients from 1989 to 2012

OBJECTIVE

To assess the impact and results of treatment of CML in the general population, we conducted a population-based, nationwide study on 3585 CML patients diagnosed between 1989 and 2012 in the Netherlands.

METHODS

Patient demographics were obtained from the Netherlands Cancer Registry. Information on age, gender, year of diagnosis, first treatment, and date of death were recorded. Overall survival (OS) was adjusted for death rates in the normal population.

RESULTS

Incidence in males decreased slightly from 1.2 per 100.000 person years (PY) in 1989-2000 to 0.9 in 2001-2012. For females, incidence remained stable with 0.7 per 100.000 PY in both periods. Incidence was age dependent and highest in males in the last decades of life. Treatment before 2000 mainly consisted of chemotherapy, while after 2007 TKI use was 88%. Five-year relative survival was only 36% before the introduction of TKIs but significantly increased to 79% after the introduction of TKI.

CONCLUSIONS

This study gives insight into CML incidence, treatment, and survival in routine care in the Netherlands. Although OS improved since the introduction of TKIs, there is still room for further improvement.

Long term outcome of Ph+ CML patients achieving complete cytogenetic remission with interferon based therapy moving from interferon to imatinib era

Interferon α (IFNα) prolongs survival of CML patients achieving CCyR and potentially synergizes with TKIs. We report on the molecular status and long term outcome of 121 patients who were treated in Italy between 1986 and 2000 with IFNα based therapy and who obtained CCyR. After a median follow up of 16.5 years, 74 (61%) patients were switched to standard imatinib: 48 (65%) lost the CCyR on IFNα, and 36 (75%) are alive and in CCyR; 26 (35%) were switched to imatinib when they were still in CCyR on IFNα, and all 26 are alive and in CCyR. Forty-seven patients (39%) were never switched to imatinib: 24 (51%) continued and 23 (49%) discontinued IFNα, respectively, and 39/47 (83%) are alive and in CCyR. At last follow-up, the BCR-ABL transcripts level was available in 96/101 living patients (95%) The BCR-ABL:ABL ratio was between 0.1 and 0.01% (MR(3.0) ) in 17%, and less than 0.01% (MR(4.0) ) in 81% of patients. No patient was completely molecular negative (MR(4.5) or MR(5.0) ). The OS at 10 and 20 years is 92 and 84%, respectively. This study confirms that CCyR achieved with IFNα and maintained with or without imatinib or any other therapy significantly correlates with long term survival in CML patients who mostly have MR(4.0) . Complete molecular response (MR(4.5) or MR(5.0) ) seems to be unnecessary for such a long survival. This study further supports development of studies testing the clinical effect of the combinations of TKIs with IFNα.

High-vs low-dose cytarabine combined with interferon alfa in patients with first chronic phase chronic myeloid leukemia. A prospective randomized phase III study

A prospective randomized phase III study was performed to evaluate whether intensified cytarabine would induce a higher response rate and longer event-free interval as compared to low-dose cytarabine in chronic myeloid leukemia (CML). One hundred and eighteen patients with CML in early chronic phase entered the study. Twenty-eight out of 32 patients assigned to group A received two cycles of a combination of intensified cytarabine and idarubicin followed by interferon alfa (IFN-α) maintenance, 28 patients in group B received standard treatment by a combination of low-dose cytarabine and IFN-α. Forty-nine patients with a human leukocyte antigen-identical sibling donor proceeded to allogeneic stem cell transplantation (allo-SCT) and nine patients were excluded from the analysis. Hematological response was observed in 97% of the patients in group A vs 86% of the patients in group B during the first year of treatment. In group A, 16 patients (50%) achieved a major cytogenetic response, which compared to seven patients (25%) with a major cytogenetic response in group B. With a median follow-up of 58 months (range 34–76), event-free survival was not significantly different between arms A and B. The estimated 5-year survival rate was 56% in the intensified arm and 77% in the low-dose arm (P = 0.05). Recipients of allo-SCT showed a 5-year estimated survival rate of 55%. Although intensified cytarabine induced a higher initial percentage of major and complete cytogenetic responses, responses were not sustained by IFN-α maintenance therapy.

Identification of genes potentially involved in disease transformation of CML

In patients with chronic myeloid leukemia (CML) who do not reach a (near) complete cytogenetic response, the disease progresses over several years from an indolent, chronic phase into a rapidly fatal blast crisis. Events that are responsible for this transformation process are largely unknown. To identify changes in gene expression that occurred during the course of the disease, we performed cDNA subtraction on sequentially stored peripheral blood mononuclear cell pellets, collected throughout the course of disease of a single CML patient. In total, 32 differentially expressed sequences were identified, of which 27 corresponded to known genes. On quantitative PCR, eight of these genes, YWHAZ, GAS2, IL8, IL6, PBEF1, CCL4, SAT and MMRN, showed comparable differential expression in additional CML patient samples. This set of genes can be considered as a starting point for further research on causes of disease transformation in CML and may lead to new targets in the treatment of resistant CML.

Autologous hematopoietic cell transplantation for chronic myelogenous leukemia

Experimental and clinical evidence for persistence of polyclonal Philadelphia chromosome negative (Ph-) progenitors in chronic myelogenous leukemia (CML) patients has provided the rationale for autologous transplantation. Clinical trials of autologous transplantation suggest that this procedure can induce cytogenetic remissions in a subset of patients and may be associated with longer-than-expected patient survival. Most autologous transplant recipients, however, continue to have evidence of persistent leukemia. Recent reports indicating that it is possible to collect sufficient numbers of Ph- peripheral blood stem cells for autologous transplantation from most patients in complete cytogenetic remission on imatinib treatment have rekindled interest in autologous transplantation in CML. Additional approaches to eliminate residual disease in autografts and to sustain cytogenetic response after transplantation, however, will be required to achieve long-term restoration of Ph- hematopoiesis. Several promising methods to improve purging of the autograft and for more effective elimination of residual leukemia are being explored.