Protein kinase inhibitors for acute leukemia

Impact of aging on acute myeloid leukemia epidemiology and survival outcomes: A real-world, population-based longitudinal cohort study

Acute myeloid leukemia (AML) is a severe and fatal form of leukemia that is prevalent in the older population. In this longitudinal retrospective study, we investigated the epidemiology and survival rates of patients diagnosed with de novo acute myeloid leukemia in South Korea from Jan 1, 2011, to Aug 31, 2020. We used real-world data from the Health Insurance Review and Assessment Service database. We observed an increase in the number of acute myeloid leukemia cases, with age-specific incidence rates escalating in older patients. In contrast a long-term decrease from 1.94 to 1.77 per 100,000 individuals was found in the age-standardized incidence rates. Meanwhile, age-standardized prevalence rates ascended from 8.93 to 9.67 per 100,000 individuals, with a remarkable increase in the age-specific prevalence rate for those aged 80 years and above. Survival rates were notably better in younger or treated patients, and in those who underwent Hematopoietic stem cell transplantation. The time of diagnosis did not affect the survival of patients younger than 65 years. However, the most recent survival rates were significantly lower for patients 65 or older, as shown in the unadjusted Cox survival analysis. After adjustments in the analysis, it was found that the overall survival rates of the most recently diagnosed group improved significantly compared with those diagnosed earlier, with a hazard ratio of 0.90 (95% confidence interval, 0.84-0.97). This improvement may potentially be influenced by the enhanced treatment alternatives available for newly diagnosed older patients aged 65 years or older. In conclusion, aging appears to fuel an increase in the number of acute myeloid leukemia cases and mortality. Further studies are warranted to understand the impact of aging on acute myeloid leukemia treatment outcomes and devise efficacious care strategies for older patients.

Kinase Inhibitors in Genetic Diseases

Over the years, several studies have shown that kinase-regulated signaling pathways are involved in the development of rare genetic diseases. The study of the mechanisms underlying the onset of these diseases has opened a possible way for the development of targeted therapies using particular kinase inhibitors. Some of these are currently used to treat other diseases, such as cancer. This review aims to describe the possibilities of using kinase inhibitors in genetic pathologies such as tuberous sclerosis, RASopathies, and ciliopathies, describing the various pathways involved and the possible targets already identified or currently under study.

Anlotinib exerts potent antileukemic activities in Ph chromosome negative and positive B-cell acute lymphoblastic leukemia via perturbation of PI3K/AKT/mTOR pathway

OBJECTIVES

Despite advances in the development of novel targeted therapies, the need for B-ALL alternative treatments has not been met. Anlotinib could blunt the proangiogenic activity of VEGFR, PDGFR, and FGFR, and has shown strong antitumor activities across multiple tumors. However, anlotinib cytotoxicity against B-ALL has not ever been evaluated, thus prompting us to initiate this study.

METHODS

Expression2Kinases program was used to identify potential treatment targets. Cell viability and apoptosis were determined by CCK-8 and Annexin V/PI staining kit, respectively. qRT-PCR and Western blotting were utilized to investigate the molecular mechanisms. In vivo antileukemia activity of Anlotinib was evaluated in a Ph⁺ B-ALL patient-Derived Xenograft (PDX) model.

RESULTS

Compared with treatment-naive B-ALL cases, RR B-ALL patients had higher activities in the VEGF/VEGFR signaling and the PI3K/AKT/mTOR pathway. Exposure of Ph^- and Ph⁺ B-ALL cells to anlotinib resulted in significant cell viability reduction, apoptosis enhancement, and cell cycle arrest at G2/M phase. Importantly, anlotinib treatment led to remarkably decreased leukemia burdens and extended the survival period in a Ph⁺ B-ALL PDX model. Blockade of the role of the proangiogenic mediators, comprising VEGFR2, PDGFR-beta, and FGFR3, played a critical role in the cytotoxicity of anlotinib against Ph^- and Ph⁺ B-ALL. Moreover, anlotinib dampened the activity of PI3K/AKT/mTOR pathway that resides in the convergence of the three mentioned proangiogenic signals.

CONCLUSION

This work provides impressive preclinical evidence of anlotinib against Ph^- and Ph⁺ B-ALL and raises a rationale for future clinical evaluation of this drug in the management of Ph^- and Ph⁺ B-ALL.

Antileukemic Activity and Molecular Docking Study of a Polyphenolic Extract from Coriander Seeds

Leukemia is a group of hematological neoplastic disorders linked to high mortality rates worldwide, but increasing resistance has led to the therapeutic failure of conventional chemotherapy. This study aimed to evaluate in vitro the antileukemic activity and potential mechanism of action of a polyphenolic extract obtained from the seeds of Coriandrum sativum L. (CSP). A methylthiazoletetrazolium assay was performed to assess the CSP cytotoxicity on chronic (K562) and acute (HL60) myeloid leukemia cell lines and on normal Vero cell line. CSP toxicity was also evaluated in vivo using the OECD 423 acute toxicity model on Swiss albino mice. The results demonstrated a remarkable antitumoral activity against K562 and HL60 cell lines (IC₅₀ = 16.86 µM and 11.75 µM, respectively) although no cytotoxicity was observed for the Vero cells or mice. A silico study was performed on the following receptors that are highly implicated in the development of leukemia: ABL kinase, ABL1, BCL2, and FLT3. The molecular docking demonstrated a high affinity interaction between the principal CSP components and the receptors. Our findings demonstrated that CSP extract has remarkable antileukemic activity, which is mainly mediated by the flavonoids, catechins, and rutin, all of which showed the highest binding affinity for the targeted receptors. This study revealed a promising active compound alternative research-oriented biopharmacists to explore.

Inference of kinase-signaling networks in human myeloid cell line models by Phosphoproteomics using kinase activity enrichment analysis (KAEA)

BACKGROUND

Despite the introduction of targeted therapies, most patients with myeloid malignancies will not be cured and progress. Genomics is useful to elucidate the mutational landscape but remains limited in the prediction of therapeutic outcome and identification of targets for resistance. Dysregulation of phosphorylation-based signaling pathways is a hallmark of cancer, and therefore, kinase-inhibitors are playing an increasingly important role as targeted treatments. Untargeted phosphoproteomics analysis pipelines have been published but show limitations in inferring kinase-activities and identifying potential biomarkers of response and resistance.

METHODS

We developed a phosphoproteomics workflow based on titanium dioxide phosphopeptide enrichment with subsequent analysis by liquid chromatography tandem mass spectrometry (LC-MS). We applied a novel Kinase-Activity Enrichment Analysis (KAEA) pipeline on differential phosphoproteomics profiles, which is based on the recently published SetRank enrichment algorithm  with reduced false positive rates. Kinase activities were inferred by this algorithm using an extensive reference database comprising five experimentally validated kinase-substrate meta-databases complemented with the NetworKIN in-silico prediction tool. For the proof of concept, we used human myeloid cell lines (K562, NB4, THP1, OCI-AML3, MOLM13 and MV4-11) with known oncogenic drivers and exposed them to clinically established kinase-inhibitors.

RESULTS

Biologically meaningful over- and under-active kinases were identified by KAEA in the unperturbed human myeloid cell lines (K562, NB4, THP1, OCI-AML3 and MOLM13). To increase the inhibition signal of the driving oncogenic kinases, we exposed the K562 (BCR-ABL1) and MOLM13/MV4-11 (FLT3-ITD) cell lines to either Nilotinib or Midostaurin kinase inhibitors, respectively. We observed correct detection of expected direct (ABL, KIT, SRC) and indirect (MAPK) targets of Nilotinib in K562 as well as indirect (PRKC, MAPK, AKT, RPS6K) targets of Midostaurin in MOLM13/MV4-11, respectively. Moreover, our pipeline was able to characterize unexplored kinase-activities within the corresponding signaling networks.

CONCLUSIONS

We developed and validated a novel KAEA pipeline for the analysis of differential phosphoproteomics MS profiling data. We provide translational researchers with an improved instrument to characterize the biological behavior of kinases in response or resistance to targeted treatment. Further investigations are warranted to determine the utility of KAEA to characterize mechanisms of disease progression and treatment failure using primary patient samples.

Effect of PDCA-based nursing management model on the quality of life and complications of patients with acute leukemia undergoing chemotherapy

OBJECTIVE

To assess the influence of PDCA-based nursing management model on the quality of life (QOL) and complications of patients with acute leukemia undergoing chemotherapy.

METHODS

In this study, we randomly divided 118 patients with acute leukemia undergoing chemotherapy in our hospital into an observation group (n=59) and a control group (n=59). The control group was implemented routine nursing while the observation group was implemented PDCA-based nursing management. The anxiety, depression, QOL, cancer fatigue, total complication rate, sleep quality, and patients' satisfaction were compared between the two groups.

RESULTS

The SAS and SDS scores of the observation group were significantly lower than those of the control group (P<0.05). The scores of physical function, general health, social function, emotional role, and mental health of the observation group were superior to those of the control group (all P<0.05). The 4 dimensions of behavior/severity, sense, emotion and cognition/mood in the observation group were significantly lower than those of the control group (all P<0.05). The incidence of complications such as nausea and vomiting, infection, bleeding, phlebitis, bone marrow suppression and mucositis in the observation group was significantly lower than that in the control group (P<0.05). The scores of sleep quality in the observation group were significantly lower than those of the control group (all P<0.05). The observation group's satisfaction with PDCA-based nursing management was markedly higher than that of the control group (P<0.05).

CONCLUSION

The PDCA-based nursing management model applied to patients with acute leukemia undergoing chemotherapy has shown good effects, which can improve depression, anxiety, cancer fatigue, sleep quality and QOL. It also significantly reduced the incidence of complications and improved patients' satisfaction, which was worth of clinical application.

Protein Tyrosine Kinases: Their Roles and Their Targeting in Leukemia

Simple Summary

Protein phosphorylation is a key regulatory mechanism that controls a wide variety of cellular responses. This process is catalysed by the members of the protein kinase superfamily that are classified into two main families based on their ability to phosphorylate either tyrosine or serine and threonine residues in their substrates. Massive research efforts have been invested in dissecting the functions of tyrosine kinases, revealing their importance in the initiation and progression of human malignancies. Based on these investigations, numerous tyrosine kinase inhibitors have been included in clinical protocols and proved to be effective in targeted therapies for various haematological malignancies. In this review, we provide insights into the role of tyrosine kinases in leukaemia and discuss their targeting for therapeutic purposes with the currently available inhibitory compounds.

Abstract

Protein kinases constitute a large group of enzymes catalysing protein phosphorylation and controlling multiple signalling events. The human protein kinase superfamily consists of 518 members and represents a complicated system with intricate internal and external interactions. Protein kinases are classified into two main families based on the ability to phosphorylate either tyrosine or serine and threonine residues. Among the 90 tyrosine kinase genes, 58 are receptor types classified into 20 groups and 32 are of the nonreceptor types distributed into 10 groups. Tyrosine kinases execute their biological functions by controlling a variety of cellular responses, such as cell division, metabolism, migration, cell–cell and cell matrix adhesion, cell survival and apoptosis. Over the last 30 years, a major focus of research has been directed towards cancer-associated tyrosine kinases owing to their critical contributions to the development and aggressiveness of human malignancies through the pathological effects on cell behaviour. Leukaemia represents a heterogeneous group of haematological malignancies, characterised by an uncontrolled proliferation of undifferentiated hematopoietic cells or leukaemia blasts, mostly derived from bone marrow. They are usually classified as chronic or acute, depending on the rates of their progression, as well as myeloid or lymphoblastic, according to the type of blood cells involved. Overall, these malignancies are relatively common amongst both children and adults. In malignant haematopoiesis, multiple tyrosine kinases of both receptor and nonreceptor types, including AXL receptor tyrosine kinase (AXL), Discoidin domain receptor 1 (DDR1), Vascular endothelial growth factor receptor (VEGFR), Fibroblast growth factor receptor (FGFR), Mesenchymal–epithelial transition factor (MET), proto-oncogene c-Src (SRC), Spleen tyrosine kinase (SYK) and pro-oncogenic Abelson tyrosine-protein kinase 1 (ABL1) mutants, are implicated in the pathogenesis and drug resistance of practically all types of leukaemia. The role of ABL1 kinase mutants and their therapeutic inhibitors have been extensively analysed in scientific literature, and therefore, in this review, we provide insights into the impact and mechanism of action of other tyrosine kinases involved in the development and progression of human leukaemia and discuss the currently available and emerging treatment options based on targeting these molecules.

Recent Advances in Molecular Diagnosis and Prognosis of Childhood B Cell Lineage Acute Lymphoblastic Leukemia (B-ALL)

B cell lineage acute lymphoblastic leukemia is the most common leukemia occurring in children and young adults and is the leading cause of cancer related deaths. The 5 year overall survival outcome in children with B-ALL has improved significantly in the last few decades. In the past, the discovery of various genetic alterations and targeted therapy have played a major role in decreasing disease-related deaths. In addition, numerous advances in the pathogenesis of B-ALL have been found which have provided better understanding of the genes involved in disease biology with respect to diagnostic and prognostic implications. Present review will summarize current understanding of risk stratification, genetic factors including cytogenetics in diagnosis and prognosis of B-ALL.

Development of a highly sensitive method for detection of FLT3D835Y

Background

Acute myeloid leukemia (AML) is a malignant hematological neoplasm of myeloid progenitor cells. Mutations of FLT3 in its tyrosine kinase domain (FLT3-TKD) are found in ~ 8% of patients with AML, with D835Y as the most common substitution. This mutation activates survival signals that drives the disease and is resistant to the first generation FLT3 inhibitors. Development of a highly sensitive method to detect FLT3D835Y is important to direct therapeutic options, predict prognosis, and monitor minimal residual disease in patients with AML.

Methods and results

In the present study, we developed a highly sensitive FLT3D835Y detection method by using the restriction fragment nested allele-specific PCR technique. The method consists of three steps: 1) initial amplification of DNA samples with PCR primers surrounding the FLT3D835Y mutation site, 2) digestion of the PCR products with restriction enzyme EcoRV that only cleaves the wild type allele, and 3) detection of FLT3D835Y by allele-specific PCR with nested primers. We were able to detect FLT3D835Y with a sensitivity of 0.001% by using purified plasmid DNAs and blood cell DNAs containing known proportions of FLT3D835Y. We analyzed blood cell DNA samples from 64 patients with AML and found six FLT3D835Y-positive cases, two of which could not be detected by conventional DNA sequencing methods. Importantly, the method was able to detect FLT3D835Y in a sample collected from a relapsed patient while the patient was in complete remission with negative MRD determined by flow cytometry. Therefore, our RFN-AS-PCR detected MRD after treatment that was missed by flow cytometry and Sanger DNA sequencing, by conventional methods.

Conclusions

We have developed a simple and highly sensitive method that will allow for detection of FLT3D835Y at a very low level. This method may have major clinical implications for treatment of AML.

Prediction of Side Effects Using Comprehensive Similarity Measures

Identifying the potential side effects of drugs is crucial in clinical trials in the pharmaceutical industry. The existing side effect prediction methods mainly focus on the chemical and biological properties of drugs. This study proposes a method that uses diverse information such as drug-drug interactions from DrugBank, drug-drug interactions from network, single nucleotide polymorphisms, and side effect anatomical hierarchy as well as chemical structures, indications, and targets. The proposed method is based on the assumption that properties used in drug repositioning studies could be utilized to predict side effects because the phenotypic expression of a side effect is similar to that of the disease. The prediction results using the proposed method showed a 3.5% improvement in the area under the curve (AUC) over that obtained when only chemical, indication, and target features were used. The random forest model delivered outstanding results for all combinations of feature types. Finally, after identifying candidate side effects of drugs using the proposed method, the following four popular drugs were discussed: (1) dasatinib, (2) sitagliptin, (3) vorinostat, and (4) clonidine.

Cancer biomarkers for targeted therapy

Tumor-associated antigens (TAA) or cancer biomarkers are major targets for cancer therapies. Antibody- based agents targeting the cancer biomarkers include monoclonal antibodies (MoAbs), radiolabeled MoAbs, bispecific T cell engagers, and antibody-drug conjugates. Antibodies targeting CD19, CD20, CD22, CD30, CD33, CD38, CD79B and SLAMF7 are in clinical applications for hematological malignancies. CD123, CLL-1, B cell maturation antigen, and CD138 are targets for cancer immunotherapeutic agents, including the chimeric antigen receptor - engineered T cells. Immune checkpoint inhibitors (ICIs) against PD-1, PD-L1, and CTLA-4 have led to the revolution of cancer immunotherapy. More ICIs targeting IDO, LAG3, TIM-3, TIGIT, SIGLECs, VISTA and CD47 are being explored. Small molecule inhibitors (SMIs) against tyrosine kinase oncoproteins such as BCR-ABL, JAK2, Bruton tyrosine kinase, FLT3, EGFR, ALK, HER2, VEGFR, FGFR, MEK, and MET have fundamentally changed the landscape of cancer therapy. SMIs against BCL-2, IDHs, BRAF, PI3 kinase, mTOR, PARP, and CDKs have become the mainstay in the treatment of a variety of cancer types. To reduce and avoid off-tumor toxicities, cancer-specific TAAs such as CD33 are being manufactured through systems biology approach. Search for novel biomarkers and new designs as well as delivery methods of targeted agents are fueling the next wave of advances in cancer therapy.

CAR-T "the living drugs", immune checkpoint inhibitors, and precision medicine: a new era of cancer therapy

New advances in the design and manufacture of monoclonal antibodies, bispecific T cell engagers, and antibody-drug conjugates make the antibody-directed agents more powerful with less toxicities. Small molecule inhibitors are routinely used now as oral targeted agents for multiple cancers. The discoveries of PD1 and PD-L1 as negative immune checkpoints for T cells have led to the revolution of modern cancer immunotherapy. Multiple agents targeting PD1, PD-L1, or CTLA-4 are widely applied as immune checkpoint inhibitors (ICIs) which alleviate the suppression of immune regulatory machineries and lead to immunoablation of once highly refractory cancers such as stage IV lung cancer. Tisagenlecleucel and axicabtagene ciloleucel are the two approved CD19-targeted chimeric antigen receptor (CAR) T cell products. Several CAR-T cell platforms targeting B cell maturation antigen (BCMA) are under active clinical trials for refractory and/or relapsed multiple myeloma. Still more targets such as CLL-1, EGFR, NKG2D and mesothelin are being directed in CAR-T cell trials for leukemia and solid tumors. Increasing numbers of novel agents are being studied to target cancer-intrinsic oncogenic pathways as well as immune checkpoints. One such an example is targeting CD47 on macrophages which represents a "do-not-eat-me" immune checkpoint. Fueling the current excitement of cancer medicine includes also TCR- T cells, TCR-like antibodies, cancer vaccines and oncolytic viruses.

Recent advances on blinatumomab for acute lymphoblastic leukemia

Although complete remission rate of B cell acute lymphoblastic leukemia (B-ALL) has improved significantly over the past few decades, patients with relapsed/refractory ALL still have dismal outcome. Tyrosine kinase inhibitors, antibody–drug conjugates and chimeric antigen receptor T cell therapy are changing the therapy landscape for B- ALL. Blinatumomab, a bi-specific T cell engager, has been approved for patients with relapsed/refractory and minimal residual disease positive B-ALL. This review summarized data from recent clinical trials of blinatumomab for B-ALL treatment.

Gemtuzumab ozogamicin and novel antibody-drug conjugates in clinical trials for acute myeloid leukemia

Targeted agents are increasingly used for the therapy of acute myeloid leukemia (AML). Gemtuzumab ozogamicin (GO) is the first antibody-drug conjugate (ADC) approved for induction therapy of AML. When used in fractionated doses, GO combined with the conventional cytarabine/anthracycline-based induction chemotherapy significantly improves the outcome of previously untreated AML patients. Single-agent GO is effective and safe for AML patient ineligible for intensive chemotherapy. Multiple combination regimens incorporating GO have also been recommended as potential alternative options. In addition, several novel ADCs targeting CD33, CD123 and CLL-1 are currently undergoing preclinical or early clinical investigations. In this review, we summarized the efficacy and limitations of GO as well as novel ADCs for adult AML patients.

Isocitrate dehydrogenase inhibitors in acute myeloid leukemia

Isocitrate dehydrogenase (IDH) is a key enzyme involved in the conversion of isocitrate to α-ketoglutarate (α-KG) in the tricarboxylic acid (TCA) cycle. IDH mutation produces a neomorphic enzyme, which can lead to the abnormal accumulation of R-2-HG and promotes leukemogenesis. IDH mutation occurs in 20% of acute myeloid leukemia (AML) patients, mainly including IDH1 R132, IDH2 R140, and IDH2 R172. Different mutant isoforms have different prognostic values. In recent years, IDH inhibitors have shown good clinical response in AML patients. Hence, enasidenib and ivosidenib, the IDH2 and IDH1 inhibitors developed by Agios Pharmaceuticals, have been approved by the Food and Drug Administration on 1 August 2017 and 20 July 2018 for the treatment of adult relapsed or refractory (R/R) AML with IDH2 and IDH1 mutations, respectively. IDH inhibitor monotherapy for R/R AML is efficacious and safe; however, there are problems, such as primary or acquired resistance. Clinical trials of IDH inhibitors combined with hypomethylating agents or standard chemotherapy for the treatment of R/R AML or newly diagnosed AML, as well as in post hematopoietic stem cell transplantation as maintenance therapy, are ongoing. This article summarizes the use of IDH inhibitors in AML with IDH mutations.

Gilteritinib: a novel FLT3 inhibitor for acute myeloid leukemia

FMS-like tyrosine kinase 3- internal tandem duplication (FLT3-ITD) remains as one of the most frequently mutated genes in acute myeloid leukemia (AML), especially in those with normal cytogenetics. The FLT3-ITD and FLT3-TKD (tyrosine kinase domain) mutations are biomarkers for high risk AML and are associated with drug resistance and high risk of relapse. Multiple FLT3 inhibitors are in clinical development, including lestaurtinib, tandutinib, quizartinib, midostaurin, gilteritinib, and crenolanib. Midostaurin and gilteritinib have been approved by FDA for Flt3 mutated AML. Gilteritinib (ASP2215, Xospata) is a small molecule dual inhibitor of FLT3/AXL. The ADMIRAL study showed that longer overall survival and higher response rate are associated with gilteritinib in comparison with salvage chemotherapy for relapse /refractory (R/R) AML. These data from the ADMIRAL study may lead to the therapy paradigm shift and establish gilteritinib as the new standard therapy for R/R FLT3-mutated AML. Currently, multiple clinical trials are ongoing to evaluate the combination of gilteritinib with other agents and regimens. This study summarized clinical trials of gilteritinib for AML.

Pharmacogenetics of thiopurines

Polychemotherapeutic protocols for the treatment of pediatric acute lymphoblastic leukemia (ALL) always include thiopurines. Specific approaches vary in terms of drugs, dosages and combinations. Such therapeutic schemes, including risk-adapted intensity, have been extremely successful for children with ALL who have reached an outstanding 5-year survival of greater than 90% in developed countries. Innovative drugs such as the proteasome inhibitor bortezomib and the bi-specific T cell engager blinatumomab are available to further improve therapeutic outcomes. Nevertheless, daily oral thiopurines remain the backbone maintenance or continuation therapy. Pharmacogenetics allows the personalization of thiopurine therapy in pediatric ALL and clinical guidelines to tailor therapy on the basis of genetic variants in TPMT and NUDT15 genes are already available. Other genes of interest, such as ITPA and PACSIN2, have been implicated in interindividual variability in thiopurines efficacy and adverse effects and need additional research to be implemented in clinical protocols. In this review we will discuss current literature and clinical guidelines available to implement pharmacogenetics for tailoring therapy with thiopurines in pediatric ALL.

Treatment patterns and healthcare resource utilization in patients with FLT3-mutated and wild-type acute myeloid leukemia: A medical chart study

OBJECTIVES

To assess real-world treatment patterns and healthcare resource utilization (HRU) among patients with FLT3-mutated (FLT3mut ) and FLT3-wild-type (FLT3wt ) acute myeloid leukemia (AML).

METHODS

Data were abstracted from medical charts of patients with AML from 10 countries. Patients were grouped based on their FLT3 mutation status, age (18-64 or ≥65), and whether they were newly diagnosed (ND) or relapsed/refractory (R/R).

RESULTS

Charts of 1027 AML patients were included (183 FLT3mut 18-64 ND; 136 FLT3mut ≥65 ND; 181 FLT3mut R/R; 186 FLT3wt 18-64 ND; 159 FLT3wt ≥65 ND; 182 FLT3wt R/R). Substantial heterogeneity was observed in treatment patterns for AML. Among ND patients 18-64, the most common initial treatment was standard-to-intermediate dose cytarabine-based therapies (43.2% for FLT3mut and 55.9% for FLT3wt ); among ND patients ≥65, the most common initial treatment was hypomethylating agent-based therapies (36.0% and 47.2%). Among R/R patients, the most common initial treatment after R/R was best supportive care only (39.8% and 24.7%). HRU was substantial across cohorts during both event-free and post-event periods.

CONCLUSIONS

Treatment patterns of AML were heterogeneous and FLT3mut AML was treated more aggressively than FLT3wt disease. HRU was substantial for all cohorts, particularly after relapse or treatment failure.

Decitabine plus CLAG chemotherapy as a bridge to haploidentical transplantation in the setting of acute myeloid leukemia relapse after HLA-matched sibling transplantation: a case report

BACKGROUND

Patients with relapsed/refractory acute myeloid leukemia after hematopoietic stem cell transplantation (HSCT) have a poor prognosis, with a 2-year survival rate of 14%. The optimal treatment for these patients remains unclear. To treat these patients, we designed a new salvage regimen consisting of decitabine, cladribine, cytarabine, and granulocyte-stimulating factor (D-CLAG).

CASE PRESENTATION

Here, we describe a case of acute monocytic leukemia with a complex karyotype in a 38-year-old female patient who relapsed after her first HSCT, which was performed using a matched sibling donor. The patient did not respond to standard induction chemotherapy and subsequently achieved complete remission with the D-CLAG regimen. No severe hematological or extramedullary toxicity was observed. Subsequently, the patient received a second D-CLAG regimen as a bridge therapy and directly underwent haploidentical related HSCT. Following HSCT, the marrow showed complete hematologic and cytogenetic remission. Currently, 1 year after transplantation, the patient's general condition remains good.

CONCLUSIONS

This case suggests that the D-CLAG regimen can be an option for reinduction in relapsed refractory AML patients as a bridge to transplantation. Nevertheless, further research will be required in the future as this report describes only a single case.

Recent advances on anti-angiogenesis receptor tyrosine kinase inhibitors in cancer therapy

Angiogenesis has always been the topic of major scientific interest in the field of malignant tumors. Nowadays, targeting angiogenesis has achieved success in various carcinomas by several mechanisms, including the use of anti-angiogenic small molecule receptor tyrosine kinase inhibitors (TKIs). The development of TKIs targeting pro-angiogenic receptors, mainly vascular endothelial growth factor receptor (VEGFR) family, have significantly improved the outcome of certain types of cancers, like renal cell carcinoma, hepatocellular carcinoma, and colorectal carcinoma. However, the general response rate is not very satisfactory. The particular toxicity profile and resistance to anti-angiogenic targeted agents are unavoidable, and no specific marker is available to screen responsive patients to TKIs for precision therapy. To date, about 11 anti-angiogenic TKIs with different binding capacities to angiogenic receptor tyrosine kinase have been approved for the treatment of patients with advanced cancers. This review presents all approved anti-angiogenic small molecule receptor TKIs so far with an emphasis on their indications and clinical efficacy. We also discuss the combination between TKIs and immune checkpoint blockade inhibitors based on the most recent exciting outcome in immunotherapy.

Clinical trials of dual-target CAR T cells, donor-derived CAR T cells, and universal CAR T cells for acute lymphoid leukemia

The current treatment for pediatric acute lymphoblastic leukemia (ALL) is highly successful with high cure rate. However, the treatment of adult ALL remains a challenge, particularly for refractory and/or relapsed (R/R) ALL. The advent of new targeted agents, blinatumomab, inotuzumab ozogamycin, and chimeric antigen receptor (CAR) T cells, are changing the treatment paradigm for ALL. Tisagenlecleucel (kymriah, Novartis) is an autologous CD19-targeted CAR T cell product approved for treatment of R/R B cell ALL and lymphoma. In an attempt to reduce the relapse rate and treat those relapsed patients with antigen loss, donor-derived CAR T cells and CD19/CD22 dual-target CAR T cells are in clinical trials. Gene-edited “off-the-shelf” universal CAR T cells are also undergoing active clinical development. This review summarized new clinical trials and latest updates at the 2018 ASH Annual Meeting on CAR T therapy for ALL with a focus on dual-target CAR T and universal CAR T cell trials.

Clinical trial update on bispecific antibodies, antibody-drug conjugates, and antibody-containing regimens for acute lymphoblastic leukemia

The relapse rate remains high after chemotherapy for adult patients with acute lymphoblastic leukemia (ALL). With better molecular diagnosis and classification as well as better assessment for minimal residual disease, major progress in the treatment for refractory and/or relapsed ALL is being made. In addition to the tyrosine kinase inhibitors (TKIs) for Philadelphia chromosome-positive ALL, immunotherapeutic agents, blinatumomab, inotuzumab ozogamicin (INO), and chimeric antigen receptor (CAR) T cells, are changing the treatment paradigm for ALL. Blinatumomab and INO are being incorporated into induction chemotherapy regimens and combined with TKIs for ALL therapy. A novel low-intensity regimen, miniHCVD-INO-blinatumomab, appears to be less toxic and more effective than conventional intensive chemotherapy regimens. This review summarized new therapeutic researches of ALL and updated latest progress in clinical trials on bispecific antibodies, antibody-drug conjugates, and new regimens incorporating these novel antibodies.

Cytogenetics and FLT3-ITD mutation predict clinical outcomes in non transplant patients with acute myeloid leukemia

Background

Cytogenetic abnormalities and mutated genes indicate the role of consolidation therapy with hematopoietic stem cell transplantation (HSCT) or chemotherapy in acute myeloid leukemia (AML). In this study, we conducted a retrospective study in adult AML patients with newly diagnosed with de novo AML who did not undergo HSCT, to study long term relapse free survival (RFS) and overall survival (OS) after consolidation chemotherapy.

Methods

We recruited 141 consecutive AML patients during January 2010–June 2017, the patients received induction chemotherapy with standard dose Ara-C and Idarubicin (7 + 3 or 5 + 2 regimen) followed by intermediate (IDAC) or high dose Ara-c (HiDAC) consolidation therapy.

Results

Normal karyotype, complex, favorable, intermediate and adverse chromosomal aberrations were found in 59%, 16%, 5%, 14% and 6%, respectively. Mutated NPM1, FLT3-ITD and CEBPA genes in CN-AML were seen in 33%, 18% and 19%, respectively. A 5 year follow up, 5y-RFS was 16% and 5y-OS was 14% in the whole study population. 5y-RFS and 5y-OS in patients completed 4 cycles of consolidation therapy were 25% and 40%, respectively. Adverse cytogenetic risk and mutated FLT3-ITD were significantly associated with poor RFS (9 and 15 months, respectively) and OS (14 and 16 months, respectively), whereas patients with mutant NPM1 had favorable outcomes (RFS/OS = 51/63 months). Patients receiving 4 cycles of consolidation therapy had significantly impacts on median RFS and OS compared with those treated with 1 or 2 cycles; 15 versus 11 months (p = 0.006) and 31 versus 15 months (p < 0.001), respectively.

Conclusions

Cytogenetic and mutation tests for FLT3-ITD, NPM1 and CEBPA genes were meaningful for predicting outcomes in adult AML patients. Adverse cytogenetic abnormalities and FLT3-ITD mutation showed dismal RFS and OS.

BCR-Abl Silencing by siRNA: A Potent Approach to Sensitize Chronic Myeloid Leukemia Cells to Tyrosine Kinase Inhibitor Therapy

Nonviral gene therapy with specific short interfering RNAs (siRNAs) against BCR-Abl can be an alternative and/or supportive therapy of chronic myeloid leukemia (CML) with tyrosine kinase inhibitors (TKIs), given the often observed resistance to TKIs in clinical setting. In this study, we explored the feasibility of BCR-Abl siRNA therapy in CML K562 cells in vitro by employing a cationic polymer derived from cholesterol (Chol) grafted low-molecular weight polyethyleneimine (PEI). The first generation TKI imatinib upregulated the expression of BCR-Abl in K562 cells as expected. Delivery of BCR-Abl siRNA in both drug-sensitive and drug-resistant K562 cells significantly downregulated the mRNA levels in both cell types. Similarly, the BCR-Abl siRNA treatment arrested the growth of both drug-sensitive and drug-resistant K562 cells with no obvious differences despite a large difference in drug responsiveness. The BCR-Abl gene silencing in combination with TKI treatments exhibited significant synergism in drug-resistant K562 cells in generating substantial antileukemic activity, where the TKIs on their own were not effective. The effect of BCR-Abl siRNA and TKIs on non-CML cells (Jurkat and primary fibroblast) was negligible, indicating the specificity of the proposed therapy. This strategy can significantly overcome TKI resistance in CML cells, suggesting a feasible and effective treatment model for CML patients suffering from clinical resistances.

Transporter and Lysosomal Mediated (Multi)drug Resistance to Tyrosine Kinase Inhibitors and Potential Strategies to Overcome Resistance

Tyrosine kinase inhibitors are a class of chemotherapeutic drugs that target specific protein kinases. These tyrosine kinase inhibitors constitute a relatively new class of drugs which target for instance Bcr-Abl, Epidermal Growth Factor Receptor (EGFR) and Vascular Endothelial Growth Factor Receptor (VEGFR). Despite some initial successes, the overall therapeutic benefit of tyrosine kinase inhibitors in the clinic has been mixed. Next to mutations in the target, multidrug resistance is a major obstacle for which still no clinically effective strategies have been developed. Major mechanisms of multidrug resistance are mediated by drug efflux transporter proteins. Moreover, there is accumulating evidence that multidrug resistance can also be caused by lysosomal sequestration of drugs, effectively trapping tyrosine kinase inhibitors and preventing them from reaching their target. Lysosomal drug sequestration seems to work together with ATP-binding cassette transporters, increasing the capacity of lysosomes to mediate sequestration. Both membrane efflux transporter proteins and lysosomes present potential therapeutic targets that could reverse multidrug resistance and increase drug efficacy in combination therapy. This review describes both mechanisms and discusses a number of proposed strategies to circumvent or reverse tyrosine kinase inhibitor-related multidrug resistance.