Persistent complete molecular remission after nilotinib and graft-versus-leukemia effect in an acute lymphoblastic leukemia patient with cytogenetic relapse after allogeneic stem cell transplantation

Emerging tyrosine kinase inhibitors for the treatment of adult acute lymphoblastic leukemia

Introduction: The broadening of targeted and immunotherapeutic strategies markedly impacted on the management of acute lymphoblastic leukemia (ALL). The advent of tyrosine kinase inhibitors (TKIs) changed the history of Philadelphia-chromosome positive (Ph+) ALL. Nowadays, almost all Ph+ ALL patients treated with TKIs achieve a complete hematologic response, and most become minimal residual disease negative. In Ph- ALL, genomic profiling studies have identified a subtype associated with a high relapse risk and a transcriptional profile similar to that of Ph+ ALL, the so-called Ph-like ALL. Given the high prevalence of kinase-activating lesions in this subset, there is compelling evidence from experimental models and clinical observations favoring TKI administration.Areas covered: We discuss the main findings exploring the efficacy of TKIs in ALL.Expert opinion: The use of more potent TKIs will further enhance the inhibitory activity on leukemia cells and increase the possibility of eradicating the disease at a molecular level. In the future, 'combined' approaches of different inhibitors may be considered to prevent/avoid resistance and/or mutations. A rapid identification of Ph-like ALL patients is needed to propose early TKI-based intervention. Several questions remain open, including the initial TKI choice in Ph+ ALL and whether Ph-like ALL patients might benefit from immunotherapy.

Recent advances in Bcr-Abl tyrosine kinase inhibitors for overriding T315I mutation

BCR-ABL is a gene produced by the fusion of the bcr gene and the c-abl proto-oncogene and is considered to be the main cause of chronic myelogenous leukemia (CML) production. Therefore, the development of selective Bcr-Abl kinase inhibitors is an attractive strategy for the treatment of CML. However, in the treatment of CML with a Bcr-Abl kinase inhibitor, the T315I gatekeeper mutant disrupts the important contact interaction between the inhibitor and the enzyme, resistant to the first- and second-generation drugs currently approved, such as imatinib, bosutinib, nilotinib, and dasatinib. In order to overcome this special resistance, several different strategies have been explored, and many molecules have been studied to effectively inhibit Bcr-Abl T315I. Some of these molecules are still under development, and some are being studied preclinically, and still others are in clinical research. Herein, this review reports some of the major examples of third-generation Bcr-Abl inhibitors against the T315I mutation.

Selective inhibitors of nuclear export (SINE)--a novel class of anti-cancer agents

Dysregulation of the nucleo-cytoplasmic transport of proteins plays an important role in carcinogenesis. The nuclear export of proteins depends on the activity of transport proteins, exportins. Exportins belong to the karyopherin β superfamily. Exportin-1 (XPO1), also known as chromosomal region maintenance 1 (CRM1), mediates transport of around 220 proteins. In this review, we summarized the development of a new class of antitumor drugs, collectively known as selective inhibitors of nuclear export (SINE). KPT-330 (selinexor) as an oral agent is showing activities in early clinical trials in both solid tumors and hematological malignancies.

Novel agents and biomarkers for acute lymphoid leukemia

New genetic markers for adult acute lymphoblastic leukemia (ALL) have been found to have prognostic impact, such as the lymphoid transcription factor gene IKZF1 alterations, which are associated with a high rate of leukemic relapse in B-ALL. Although complete remission rates by induction chemotherapy in ALL are now high, the long-term survival is still disappointing. Improvements in the survival outcome of ALL have been observed in young adults as a result of the use of pediatric inspired regimens and the broadening of the number of patients who are eligible for allogeneic SCT. Development of new and less toxic agents also provide promise to improve the outcome in adult ALL, such as tyrosine kinase inhibitors in Ph-positive ALL, rituximab in CD20-positive disease, blinatumomab in precursor B-ALL and nelarabine in T-lineage ALL. Challenges for the future are to implement genomic profiling into the clinical setting to guide risk stratification and providing novel targets for tailored therapies.