State-of-the-art in the treatment of chronic myeloid leukaemia:

Pregnancy Outcomes in Chronic Myeloid Leukemia: A Single Center Experience

PURPOSE

The aim of the current work was to report the effect of imatinib on pregnancy in patients with chronic myeloid leukemia (CML).

METHODS

Data were collected between January 1998 and December 2014. One hundred four patients met inclusion criteria, and we report the results of 104 pregnancies-conceived by the participant or partner-while being on imatinib therapy for CML.

RESULTS

Fifty-eight patients were male and 46 were female. Eighty-three patients, 20 patients, and one patient were had CML in the chronic phase, accelerated phase, or blast phase, respectively. Of 46 female patients, 21 underwent abortion (spontaneous, n = 36.9; elective termination, n = 8.6%). In the case of full-term pregnancy in the female partners of male patients with CML, all outcomes were uneventful. Of 46 female patients, 25 had full-term pregnancy outcomes. During the pre-imatinib era (total n = 6), patients were treated with hydroxyurea, interferon-alpha, and therapeutic leukapheresis. A total 10 of 19 pregnant patients continued on imatinib until their delivery and experienced the following outcomes: normal full-term deliveries (n = 7), preterm delivery (n = 1), omphalocele (n = 1), and craniosynostosis (n = 1). Of those who discontinued imatinib after counseling (n = 9), eight patients had full-term normal delivery, of which two patients required leukapheresis and one patient expired. All patients who continued on imatinib while pregnant were in complete cytogenetic response and major molecular response (MMR) before pregnancy, during pregnancy, and postpregnancy. Of nine patients who discontinued imatinib, two lost MMR during the third trimester and all of these patients were in complete cytogenetic response and MMR before pregnancy.

CONCLUSION

It is clear that there is no standard of care for the best treatment of CML in the case of pregnancy. Interferon and/or leukapheresis will be included as treatment options. Patients can have normal pregnancies even with the administration of imatinib at the risk of congenital anomalies, intervention for which can be done after birth.

Onset of chronic myeloid leukemia with complex karyotype in a pregnant patient: case report and revision of literature

Approximately 10%–12% of patients in chronic-phase chronic myeloid leukemia (CP-CML) have additional chromosomal aberrations at diagnosis; moreover, CML occurs in up to 10% of pregnancy-associated leukemias, with an annual incidence of 1 per 100,000 pregnancies. In this report we describe the case of a 36-year-old female with CP-CML diagnosed in the 18th week of pregnancy and with a new complex variant translocation t(4;9;22;21)(q24;q34;q11;q22) and an additional chromosomal aberration t(1;20)(p36;p11). In consideration of her pregnancy, the patient strictly monitored her blood cell count without any specific treatment. At 32 weeks of pregnancy, the patient delivered via cesarean section a healthy baby girl. After 10 days from childbirth, dasatinib was started at a standard dosage of 100 mg/day and 3 months later complete cytogenetic response and major molecular response were obtained, with the achievement of an optimal response according to European Leukemia Net recommendations and showing efficacy of this tyrosine kinase inhibitor (TKI) in the presence of a complex karyotype.

Rational drug repurposing using sscMap analysis in a HOX-TALE model of leukemia

Drug discovery and development are often hampered by lack of target identification and clinical tractability. Repurposing of approved drugs to life-threatening diseases such as leukemia is emerging as a promising alternative approach. Connectivity mapping systems link approved drugs with disease-related gene signatures. Relevant preclinical models provide essential tools for system validation and proof-of-concept studies. Herein we describe procedures aimed at generating disease-based gene signatures and applying them to established cross-referencing databases of potential candidate drugs. As a proof of principle, we present the identification of Entinostat as a candidate drug for the treatment of HOX-TALE-related leukemia.

Automating crystallographic structure solution and refinement of protein-ligand complexes

High-throughput drug-discovery and mechanistic studies often require the determination of multiple related crystal structures that only differ in the bound ligands, point mutations in the protein sequence and minor conformational changes. If performed manually, solution and refinement requires extensive repetition of the same tasks for each structure. To accelerate this process and minimize manual effort, a pipeline encompassing all stages of ligand building and refinement, starting from integrated and scaled diffraction intensities, has been implemented in Phenix. The resulting system is able to successfully solve and refine large collections of structures in parallel without extensive user intervention prior to the final stages of model completion and validation.

How I treat leukemia during pregnancy

Leukemia in pregnancy remains a challenging therapeutic prospect. The prevalence is low at ∼1 in 10 000 pregnancies, and as a result data are limited to small retrospective series and case reports, rendering evidence-based recommendations for management strategies difficult. The management of the leukemias in pregnancy requires close collaboration with obstetric and neonatology colleagues as both the maternal and fetal outcomes must be taken into consideration. The decision to introduce or delay chemotherapy must be balanced against the impact on maternal and fetal survival and morbidity. Invariably, acute leukemia diagnosed in the first trimester necessitates intensive chemotherapy that is likely to induce fetal malformations. As delaying treatment in this situation is usually inappropriate, counseling with regard to termination of pregnancy is often essential. For chronic disease and acute leukemia diagnosed after the second trimester, therapeutic termination of the pregnancy is not inevitable and often, standard management approaches similar to those in nongravid patients can be used. Here, the management of the acute and chronic leukemias will be addressed.

[Tyrosine kinases in etiopathogenesis and therapy of malignant diseases--C-kit activating mutations]

In the last 15 years, the introduction of molecular biology methods and techniques for identifying mutations and measuring gene expression levels of mutated genes since recently, have enabled precise molecular diagnostics, classification and assessment of prognosis and therapeutic response of malignant disease to specific therapies. The increased knowledge of the cancer genome and the introduction of multiple new technologies in cancer research have significantly improved the drug discovery process, leading to key success in targeted cancer therapeutics, including tyrosine kinase inhibitors. Tyrosine kinase inhibitors are the molecular targeted neoadjuvant and adjuvant therapy of various malignancies. Many more results which are expected from ongoing trials are necessary to specify the appropriate dosages, stages at which to start the treatment, and which therapeutic combinations to apply.

Delivery of therapeutic shRNA and siRNA by Tat fusion peptide targeting BCR-ABL fusion gene in Chronic Myeloid Leukemia cells

Gene silencing by RNA interference (RNAi) is a promising therapeutic approach for a wide variety of diseases for which the biological cause is known. The main challenge remains the ineffective RNAi delivery inside the cells. Non-viral gene delivery vectors have low immunogenicity compared to viral vectors, but are constrained by their reduced transfection efficiency. Silencing of the bcr-abl gene expression by RNAi confers therapeutic potential in Chronic Myeloid Leukemia (CML), but is limited by the cytotoxicity of the existing delivery methods. Here, we present evidence that the fusion between the cell penetrating peptide (CPP) HIV-Tat (49-57) and the membrane lytic peptide (LK15), Tat-LK15, mediates high transfection efficiency in delivering short hairpin RNA (shRNA) and small interfering RNA (siRNA) targeting the BCR-ABL oncoprotein in K562 CML cells. Our results show that shRNA complexes induce a more stable gene silencing of bcr-abl when compared to silencing mediated by siRNA complexes. In addition, silencing of the BCR-ABL oncoprotein by both shRNA and siRNA delivered by Tat-LK15 is more efficient and longer lasting than that achieved using Lipofectamine and more importantly without considerable cytotoxicity. In these terms Tat-LK15 can be an alternative to DNA/siRNA delivery in difficult-to-transfect leukemic cells.

Mechanisms of Resistance to Imatinib and Second-Generation Tyrosine Inhibitors in Chronic Myeloid Leukemia

Targeted therapy in the form of selective tyrosine kinase inhibitors (TKI) has transformed the approach to management of chronic myeloid leukemia (CML) and dramatically improved patient outcome to the extent that imatinib is currently accepted as the first-line agent for nearly all patients presenting with CML, regardless of the phase of the disease. Impressive clinical responses are obtained in the majority of patients in chronic phase; however, not all patients experience an optimal response to imatinib, and furthermore, the clinical response in a number of patients will not be sustained. The process by which the leukemic cells prove resistant to TKIs and the restoration of BCR-ABL1 signal transduction from previous inhibition has initiated the pursuit for the causal mechanisms of resistance and strategies by which to surmount resistance to therapeutic intervention. ABL kinase domain mutations have been extensively implicated in the pathogenesis of TKI resistance, however, it is increasingly evident that the presence of mutations does not explain all cases of resistance and does not account for the failure of TKIs to eliminate minimal residual disease in patients who respond optimally. The focus of exploring TKI resistance has expanded to include the mechanism by which the drug is delivered to its target and the impact of drug influx and efflux proteins on TKI bioavailability. The limitations of imatinib have inspired the development of second generation TKIs in order to overcome the effect of resistance to this primary therapy. (Clin Cancer Res 2009;15(24):7519-27).

Translational research in complex etiopathogenesis and therapy of hematological malignancies: the specific role of tyrosine kinases signaling and inhibition

During the recent genomics and proteomics era, high-resolution, genome-wide approaches have revealed numerous promising new drug targets and disease biomarkers, accelerating and emphasizing the need for targeted molecular therapy compounds. Significant progress has been made in understanding the pathogenesis of hematological malignancies there by, revealing new drug targets. Introduction of multiple new technologies in cancer research have significantly improved the drug discovery process, leading to key success in targeted cancer therapeutics, including tyrosine kinase inhibitors. The studies of receptor tyrosine kinases and their role in malignant transformation are already translated from the preclinical level (cell-based and animal models) to clinical studies, enabling the more complete understanding of tumor cell biology and improvement of tumor therapy.

Current Therapies for Chronic Myeloid Leukemia

Management strategies for patients with chronic-phase chronic myeloid leukemia (CML) have changed dramatically since the introduction of imatinib into clinical trials in 1998. Imatinib is generally accepted, at present, to be the most appropriate initial therapy for newly diagnosed chronic-phase CML; however, a proportion of patients will not respond adequately. Many of these patients may benefit from alternative treatment strategies, including second- and third-generation BCR-ABL kinase inhibitors and allogeneic hematopoietic stem cell transplantation (HSCT). Additionally, with continued improvements in molecular monitoring, it is much more clinically routine to measure ongoing treatment efficacy or characterize pending disease relapse via molecular analysis. The challenge is to now combine molecular monitoring information with timely treatment decisions to achieve the best possible outcomes. Additionally, unanswered questions about HSCT remain, and include (1) What is the role of allogeneic HSCT in CML? (2) What type of transplant, reduced-intensity or myeloablative, should be performed? The goal of this article is to provide an overview of where we stand in the treatment of CML in 2008.