Chronic myeloid leukaemia: a therapeutic challenge

Chronic myeloid leukemia: reminiscences and dreams

With the deaths of Janet Rowley and John Goldman in December 2013, the world lost two pioneers in the field of chronic myeloid leukemia. In 1973, Janet Rowley, unraveled the cytogenetic anatomy of the Philadelphia chromosome, which subsequently led to the identification of the BCR-ABL1 fusion gene and its principal pathogenetic role in the development of chronic myeloid leukemia. This work was also of major importance to support the idea that cytogenetic changes were drivers of leukemogenesis. John Goldman originally made seminal contributions to the use of autologous and allogeneic stem cell transplantation from the late 1970s onwards. Then, in collaboration with Brian Druker, he led efforts to develop ABL1 tyrosine kinase inhibitors for the treatment of patients with chronic myeloid leukemia in the late 1990s. He also led the global efforts to develop and harmonize methodology for molecular monitoring, and was an indefatigable organizer of international conferences. These conferences brought together clinicians and scientists, and accelerated the adoption of new therapies. The abundance of praise, tributes and testimonies expressed by many serve to illustrate the indelible impressions these two passionate and affable scholars made on so many people's lives. This tribute provides an outline of the remarkable story of chronic myeloid leukemia, and in writing it, it is clear that the historical triumph of biomedical science over this leukemia cannot be considered without appreciating the work of both Janet Rowley and John Goldman.

Management of molecular-targeted therapy for chronic myelogenous leukemia

PURPOSE

To provide primary care providers with guidelines on the evaluation and management of treatment for patients with chronic myelogenous leukemia (CML) with emphasis on the molecular-targeted therapy imatinib mesylate.

DATA SOURCES

Research-based articles in the medical literature, review articles, and clinical practice guidelines.

CONCLUSIONS

CML is a clonal stem cell disorder causing 5,000 new cases annually. Research on molecular-targeted therapy confirms that specific protein kinases have broad consequences for the development of future drugs to treat CML. The most recent discovery is a new compound, imatinib mesylate, which has become commercially available. Currently, the standard of care for CML is this agent. This therapy has changed management strategies for treatment of patients with the diagnosis of CML.

IMPLICATIONS FOR PRACTICE

Long-term observations and evaluations are needed for final determination of treatment effectiveness; thus, primary care providers will follow patients with CML in the community. Unforeseen toxicity may surface, requiring accurate assessment and evaluation. Primary care providers will be actively involved with providing symptom management for these patients.

Perspectives on the treatment of chronic phase and advanced phase CML and Philadelphia chromosome positive ALL(1)

Chronic myeloid leukaemia (CML) is a malignant disease of the bone marrow characterised by the presence of the Philadelphia (Ph) chromosome. About 20% of acute lymphoblastic leukaemia (ALL) patients also show this genetic abnormality. A new drug, imatinib (Glivec, Novartis Pharma AG, Basel, Switzerland, and formerly STI571) is having a profound effect on the treatment and management of all stages of CML and Philadelphia chromosome positive (Ph+) ALL. New treatment algorithms are being developed. Should imatinib replace or be combined with existing therapies? To address this question, we review the pros and cons of therapy with interferon-alpha (IFN-alpha), allogeneic transplantation, autologous transplantation, imatinib, and in the case of Ph+ ALL, chemotherapy and experimental approaches. Conservative and aggressive treatments will be discussed and new molecular methods of monitoring cytogenetic response and their significance will also be reviewed.

Abnormal levels of proinflammatory cytokines in serum and monocyte cultures from patients with chronic myeloid leukemia in different stages, and their role in prognosis

Interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), primarily monocyte-derived cytokines, form a group of proinflammatory cytokines with related and overlapping spectra of activities. The role of these cytokines in chronic myeloid leukemia (CML) has been investigated. A distinctive pattern of cytokine secretion has been found in chronic myeloid leukemia in chronic phase (CML-CP), in blastic crisis (CML-BC) and in normal subjects. Serum IL-6 levels in CML-CP and CML-BC were significantly raised compared with normal controls (p = 0.0026 for CML-CP and p = 0.0011 for CML-BC). IL-6 was significantly elevated in blastic crisis of CML (103.5 +/- 20.77 pg ml-1) compared with CML-CP (37.35 +/- 10.88 pg ml-1; p = 0.014). IL-6 serum levels were found to correlate significantly with peripheral blood monocyte counts and bone marrow blast and basophil counts. We have analysed monocyte/macrophage function with respect to their ability to produce IL-1, IL-6 and TNF-alpha, spontaneously as well as in response to LPS, in comparison with normal controls. A direct correlation of IL-6 levels in unstimulated and stimulated cultures with bone marrow blast and basophil counts has been observed. From these results it is inferred that the monocyte function is impaired in CML patients, and the cytokine secretion is deficient. Our limited data suggest that serum IL-6 levels may play an important role as a prognostic marker for CML.

Molecular monitoring of residual disease in chronic myelogenous leukemia patients after therapy

The degree of tumor load reduction after therapy, which is determined by the degrees of cytoreduction and cytogenetic response, is an important prognostic factor for patients with chronic myelogenous leukemia (CML). Conventional metaphase analysis is considered to be the "gold standard" for evaluating cytogenetic response. The frequency of cytogenetic analysis can be reduced considerably if patients are monitored by molecular methods, such as quantitative Southern blot, fluorescence in situ hybridization (FISH), quantitative western blot, or competitive reverse transcriptase polymerase chain reaction (RT-PCR). Molecular methods can be performed on peripheral blood specimens and are therefore less invasive than cytogenetic analyses of bone marrow metaphases. Furthermore these techniques are applicable to Ph-negative/BCR-AbL-positive cases. Results obtained by Southern blotting, western blotting, and FISH are readily quantifiable but their sensitivity is not generally superior to that of cytogenetic methods. RT-PCR is by far the most sensitive method. Quantitative RT-PCR analysis is the method of choice for monitoring patients after bone marrow transplantation (BMT). Using competitive PCR in patients after BMT, reappearance and/or rising levels of BCR-ABL transcripts can be detected prior to relapse. All complete cytogenetic responders to interferon-alpha are positive for BCR-ABL transcripts. The level of residual disease spans a range over found orders of magnitude. In both interferon-alpha-treated patients and patients after BMT a good correlation between BCR-ABL transcript numbers per microgram of RNA and cytogenetic results has been found. Variables in the competitive PCR assay may be controlled for by quantification of transcripts of the normal ABL gene as an internal standard. We suggest a stepwise strategy for diagnosis and follow-up of CML patients employing molecular methods.