Targeted chronic myeloid leukemia therapy: Seeking a cure

Drug Targeting and Therapeutic Management of Chronic Myeloid Leukemia: Conventional and Nanotherapeutic Drug Options

Chronic myeloid leukemia (CML) is a blood cancer predominantly affecting older adult patients. According to the American Cancer Society, an estimated 8,860 people will be diagnosed with CML in 2022. Treatments for CML have evolved with a focus on CML phase severity or progression. Overall, there have been some breakthrough treatment options for a high percentage of patients with CML. This is largely due to the discovery of tyrosine kinase inhibitors (TKI); however, drug resistance continues to present a significant challenge for the management of CML disease.  The use of interferon (IFN), antimetabolites, and bone marrow transplants provide alternative treatment options, but also present with limitations including severe side effects, toxicity, and graft versus host disease. Nanomedicine has demonstrated benefits in terms of efficacy, often reducing or eliminating unwanted toxicities associated with the use of conventional drug agents. This review summarizes rational molecular targets of CML drugs and provides highlights of current FDA-approved agents for the treatment of CML. Additionally, this communication includes an overview of the limitations of conventional treatments and how nanomedicine has addressed challenges encountered during CML treatment. .

Philadelphia Chromosome-Positive Leukemia in the Lymphoid Lineage-Similarities and Differences with the Myeloid Lineage and Specific Vulnerabilities

Philadelphia chromosome (Ph) results from a translocation between the breakpoint cluster region (BCR) gene on chromosome 9 and ABL proto-oncogene 1 (ABL1) gene on chromosome 22. The fusion gene, BCR-ABL1, is a constitutively active tyrosine kinase which promotes development of leukemia. Depending on the breakpoint site within the BCR gene, different isoforms of BCR-ABL1 exist, with p210 and p190 being the most prevalent. P210 isoform is the hallmark of chronic myeloid leukemia (CML), while p190 isoform is expressed in majority of Ph-positive B cell acute lymphoblastic leukemia (Ph+ B-ALL) cases. The crucial component of treatment protocols of CML and Ph+ B-ALL patients are tyrosine kinase inhibitors (TKIs), drugs which target both BCR-ABL1 isoforms. While TKIs therapy is successful in great majority of CML patients, Ph+ B-ALL often relapses as a drug-resistant disease. Recently, the high-throughput genomic and proteomic analyses revealed significant differences between CML and Ph+ B-ALL. In this review we summarize recent discoveries related to differential signaling pathways mediated by different BCR-ABL1 isoforms, lineage-specific genetic lesions, and metabolic reprogramming. In particular, we emphasize the features distinguishing Ph+ B-ALL from CML and focus on potential therapeutic approaches exploiting those characteristics, which could improve the treatment of Ph+ B-ALL.

Anti-leukemic effect of PI3K inhibition on chronic myeloid leukemia (CML) cells: shedding new light on the mitigating effect of c-Myc and autophagy on BKM120 cytotoxicity

The success in the identification of BCR/ABL tyrosine kinase role in the pathogenesis of chronic myeloid leukemia (CML) went as far as to find a path to cure this leukemia; however, compensatory activation of leukomogenic signals get across the message that the small molecule inhibitors of oncogenic pathways, along with tyrosine kinase inhibitors, might be a beneficial approach in CML treatment. The results of the present study showed that the abrogation of the phosphoinositide 3-kinase (PI3K) pathway using pan-PI3K inhibitor BKM120 exerted a cytotoxic effect against CML-derived K562 cells through both the induction of p21-mediated G2/M arrest and the stimulation of apoptosis. Notably, the apoptotic effect of the inhibitor was further confirmed by the molecular analysis showing that BKM120 significantly increased the expression of pro-apoptotic genes. To the best of our knowledge, the involvement of autophagy in resistance to BKM120 has not been yet described and our study suggests for the first time that the elevation of autophagy-related genes might serve as a compensatory pathway to cease the anti-leukemic effect of BKM120 in K562; since we found a reinforced anti-survival event when the cells were treated with BKM120 in combination with autophagy inhibitor. In conclusion, the results of the present study showed that the abrogation of PI3K using BKM120 might be a befitting approach in CML treatment, either as a single agent or in a combined-modal strategy; however, further evaluations including clinical trials and in vivo investigations are demanded to ascertain the safety and the efficacy of the inhibitor in treatment strategies.

Imatinib-induced pleural effusion: A case report

Imatinib is a tyrosine kinase inhibitor and has rarely been reported to cause pleural effusion. We report the case of an 88-year-old male, known case of gastrointestinal stromal tumor on treatment with imatinib, who presented with a 2-week history of cough and dyspnea. He was diagnosed to have a right-sided pleural effusion and thoracentesis of the fluid revealed an exudate with low adenosine deaminase and negative cytology. Withdrawal of the drug lead to resolution of symptoms. We report this case to highlight the side effect profile of imatinib and warn physicians regarding this potential adverse effect which may be mistaken for metastasis or infection.

Imatinib attenuates cerebrovascular injury and phenotypic transformation after intracerebral hemorrhage in rats

This study explored the hypothesis that intracerebral hemorrhage (ICH) promotes release of diffusible factors that can significantly influence the structure and function of cerebral arteries remote from the site of injury, through action on platelet-derived growth factor (PDGF) receptors. Four groups of adult male Sprague-Dawley rats were studied (n = 8 each): 1) sham; 2) sham + 60 mg/kg ip imatinib; 3) ICH (collagenase method); and 4) ICH + 60 mg/kg ip imatinib given 60 min after injury. At 24 h after injury, sham artery passive diameters (+3 mM EGTA) averaged 244 ± 7 µm (at 60 mmHg). ICH significantly increased passive diameters up to 6.4% and decreased compliance up to 42.5%. For both pressure- and potassium-induced contractions, ICH decreased calcium mobilization up to 26.2% and increased myofilament calcium sensitivity up to 48.4%. ICH reduced confocal colocalization of smooth muscle α-actin (αActin) with nonmuscle myosin heavy chain (MHC) and increased its colocalization with smooth muscle MHC, suggesting that ICH promoted contractile differentiation. ICH also enhanced colocalization of myosin light chain kinase (MLCK) with both αActin and regulatory 20-kDa myosin light chain. All effects of ICH on passive diameter, compliance, contractility, and contractile protein colocalization were significantly reduced or absent in arteries from animals treated with imatinib. These findings support the hypothesis that ICH promotes release into the cerebrospinal fluid of vasoactive factors that can diffuse to and promote activation of cerebrovascular PDGF receptors, thereby altering the structure, contractile protein organization, contractility, and smooth muscle phenotype of cerebral arteries remote from the site of hemorrhage.

Towards precision medicine-based therapies for glioblastoma: interrogating human disease genomics and mouse phenotypes

BACKGROUND

Glioblastoma (GBM) is the most common and aggressive brain tumors. It has poor prognosis even with optimal radio- and chemo-therapies. Since GBM is highly heterogeneous, drugs that target on specific molecular profiles of individual tumors may achieve maximized efficacy. Currently, the Cancer Genome Atlas (TCGA) projects have identified hundreds of GBM-associated genes. We develop a drug repositioning approach combining disease genomics and mouse phenotype data towards predicting targeted therapies for GBM.

METHODS

We first identified disease specific mouse phenotypes using the most recently discovered GBM genes. Then we systematically searched all FDA-approved drugs for candidates that share similar mouse phenotype profiles with GBM. We evaluated the ranks for approved and novel GBM drugs, and compared with an existing approach, which also use the mouse phenotype data but not the disease genomics data.

RESULTS

We achieved significantly higher ranks for the approved and novel GBM drugs than the earlier approach. For all positive examples of GBM drugs, we achieved a median rank of 9.2 45.6 of the top predictions have been demonstrated effective in inhibiting the growth of human GBM cells.

CONCLUSION

We developed a computational drug repositioning approach based on both genomic and phenotypic data. Our approach prioritized existing GBM drugs and outperformed a recent approach. Overall, our approach shows potential in discovering new targeted therapies for GBM.

Multi-omics approach to infer cancer therapeutic targets on chromosome 20q across tumor types

The identification of good targets is a critical step for the development of targeted therapies for cancer treatment. Here, we used a multi-omics approach to delineate potential targets on chromosome 20q, which frequently shows a complex pattern of DNA copy number amplification in many human cancers suggesting the presence of multiple driver genes. By comparing the amounts of individual mRNAs in cancer from 11 different human tissues with those in their corresponding normal tissues, we identified 18 genes that were robustly elevated across human cancers. Moreover, we found that higher expression levels of a majority of these genes were associated with poor prognosis in many human cancer types. Using DNA copy number and expression data for all 18 genes obtained from The Cancer Genome Atlas project, we discovered that amplification is a major mechanism driving overexpression of these 18 genes in the majority of human cancers. Our integrated analysis suggests that 18 genes on chromosome 20q might serve as novel potential molecular targets for targeted cancer therapy.

Platelet-derived growth factor receptor/platelet-derived growth factor (PDGFR/PDGF) system is a prognostic and treatment response biomarker with multifarious therapeutic targets in cancers

Progress in cancer biology has led to an increasing discovery of oncogenic alterations of the platelet-derived growth factor receptors (PDGFRs) in cancers. In addition, their overexpression in numerous cancers invariably makes PDGFRs and platelet-derived growth factors (PDGFs) prognostic and treatment markers in some cancers. The oncologic alterations of the PDGFR/PDGF system affect the extracellular, transmembrane and tyrosine kinase domains as well as the juxtamembrane segment of the receptor. The receptor is also involved in fusions with intracellular proteins and receptor tyrosine kinase. These discoveries undoubtedly make the system an attractive oncologic therapeutic target. This review covers elementary biology of PDGFR/PDGF system and its role as a prognostic and treatment marker in cancers. In addition, the multifarious therapeutic targets of PDGFR/PDGF system are discussed. Great potential exists in the role of PDGFR/PDGF system as a prognostic and treatment marker and for further exploration of its multifarious therapeutic targets in safe and efficacious management of cancer treatments.

The effect of BIM deletion polymorphism on intrinsic resistance and clinical outcome of cancer patient with kinase inhibitor therapy

A common deletion polymorphism within B-cell chronic lymphocytic leukemia-lymphoma like 11 gene (BIM) was deemed to be a genetic cause leading to compromised kinase inhibitor therapeutic efficacy in cancer individuals. However, the results reported were not consistent. Thus, a comprehensive meta-analysis containing 12 eligible studies including 1,532 Asian patients was conducted to investigate a steady and reliable conclusion. The results showed that BIM deletion polymorphism was significantly associated with tyrosine kinase inhibitor (TKI) clinical efficacy in term of response rate (P_h = 0.349, HR = 0.438, 95%CI = 0.274–0.699) and disease control rate (P_h = 0.941, HR = 0.370, 95%CI = 0.202–0.678) in EGFR-mutated NSCLC population, not in CML and HCC subgroups. Additionally, EGFR-mutated NSCLC patient harbored BIM deletion polymorphism was associated with a shorter progression-free survival (PFS) than those with BIM wild polymorphism (P_h = 0.580, adjusted HR = 2.194, 95%CI = 1.710–2.814). However, no significant association was examined between BIM deletion polymorphism and overall survival (OS) and toxic adverse events in EGFR-mutated NSCLC population and it was not associated with PFS and OS in HCC subgroup. These findings revealed that BIM deletion polymorphism might be a genetic cause of intrinsic resistance to TKI therapy and it could be emerged as an independent predictor to identify patients who would benefit from TKI targeted therapy in EGFR-mutated NSCLC.

Characterizing of Four Common BCR-ABL Kinase Domain Mutations (T315I, Y253H, M351T and E255K) in Iranian Chronic Myelogenous Leukemia Patients With Imatinib Resistance

Background:

Chronic myelogenous leukemia (CML) is a kind of hematopoietic stem-cell cancer. A significant number of CML patients who do not achieve an acceptable response to therapy, show acquired resistance against Imatinib. One of the most considerable causes of resistance against Imatinib as the first line of therapy, are BCR-ABL kinase domain mutations.

Objectives:

One of the most considerable causes of resistance against Imatinib as the first line of therapy, are BCR-ABL kinase domain mutations.

Patients and Methods:

The study was performed on 39 CML patients with Imatinib resistance. Basic hematologic parameters in blood samples were checked to identify hematologic response. To identify molecular response, BCR-ABL/ABL ratio was assessed by Real-time PCR. The ABL kinase domain amplification was performed by PCR. Restriction fragment length polymorphism (RFLP) was performed to detect four common mutations (T315I, Y253H, E255K and M351T). Finally the results were approved by direct sequencing.

Results:

In this study, the Y253H mutation, detected by RFLP method and confirmed by direct sequencing, was the prevalent ABL kinase domain mutation in these 39 CML patients. The G250E, V379I and L384M mutations were found in three different cases with failure molecular response. CML patients with these four ABL kinase domain mutations cannot achieve major molecular response (MMR). In addition, complete hematologic response (CHR) was observed only in the V379I mutated case and not in other mutated patients.

Conclusions:

Identification of ABL kinase domain mutations may be used as a proper and useful method for improving therapeutic strategies, avoiding delay in treatment and excessive expenditure in CML patients with Imatinib resistance.

Cancer metabolism: strategic diversion from targeting cancer drivers to targeting cancer suppliers

Drug development groups are close to discovering another pot of gold-a therapeutic target-similar to the success of imatinib (Gleevec) in the field of cancer biology. Modern molecular biology has improved cancer therapy through the identification of more pharmaceutically viable targets, and yet major problems and risks associated with late-phase cancer therapy remain. Presently, a growing number of reports have initiated a discussion about the benefits of metabolic regulation in cancers. The Warburg effect, a great discovery approximately 70 years ago, addresses the “universality” of cancer characteristics. For instance, most cancer cells prefer aerobic glycolysis instead of mitochondrial respiration. Recently, cancer metabolism has been explained not only by metabolites but also through modern molecular and chemical biological techniques. Scientists are seeking context-dependent universality among cancer types according to metabolic and enzymatic pathway signatures. This review presents current cancer metabolism studies and discusses future directions in cancer therapy targeting bio-energetics, bio-anabolism, and autophagy, emphasizing the important contribution of cancer metabolism in cancer therapy.

Inhibition of euchromatic histone methyltransferase 1 and 2 sensitizes chronic myeloid leukemia cells to interferon treatment

Background

H3K9 methylation is one of the essential histone post-translational modifications for heterochromatin formation and transcriptional repression. Recently, several studies have demonstrated that H3K9 methylation negatively regulates the type I interferon response.

Results

We report the application of EHMT1 and EHMT2 specific chemical inhibitors to sensitize CML cell lines to interferon and imatinib treatments. Inhibition of EHMT1 and EHMT2 with BIX01294 enhances the cytotoxicity of IFNα2a in four CML cell lines, K562, KCL22, BV173 and KT1 cells. Chromatin immunoprecipitation assay shows that BIX01294 treatment enhances type I interferon response by reducing H3K9me2 at the promoters of interferon-stimulated genes. Additionally, BIX01294 treatment augments IFNα2a- and imatinib-mediated apoptosis in CML cell lines. Moreover, our data suggest that the expression level of EHMT1 and EHMT2 inversely correlates with the type I interferon responsiveness in CML cell lines.

Conclusions

Our study sheds light on the role of EHMT1 and EHMT2 as potential targets in improving the efficacy of standard treatments of CML.

Overexpression of microRNA-143 inhibits growth and induces apoptosis in human leukemia cells

Microrna-143 (miR-143) has been suggested to be a tumor suppressor, yet its role in hematological tumors has not been determined. Thus, we aimed to explore the expression and function of miR-143 in leukemia cells. miR-143 expression was assessed in bone marrow samples from 63 leukemia patients and 15 healthy controls using q-PCR, and its correlation with DNMT3A expression was determined. In addition, after lentiviral-mediated miR-143 overexpression, K562 cell proliferation was evaluated using CCK-8 analysis; cell cycle progression and apoptosis were determined using flow cytometry. The expression of Bcl-2 and pro-caspase-3 and -9 was assessed by q-PCR and western blot analysis, respectively. Leukemia patients had significantly lower relative miR-143 expression than healthy controls (P=0.004), and the expression levels of miR143 and DNMTA3A were negatively correlated (r=-0.663, P=0.001). Overexpression of miR-143 decreased DNMT3A mRNA and protein expression, and significantly reduced K562 cell proliferation at 72 and 96 h (both P ≤ 0.018). In addition, reduced colony formation and cell cycle progression were observed upon miR-143 overexpression. Flow cytometric analysis revealed that the early apoptosis rate was higher in the miR-143 group than the rate in the NC group. Bcl-2 mRNA expression and pro-caspase-3 and -9 protein expression were reduced in the miR-143-expressing cells. These findings suggest that miR-143 plays an important role in leukemia cell proliferation and apoptosis, possibly through silencing of DNMT3A. Further studies are necessary to determine the prognostic value and therapeutic potential of targeting miR-143.

Monitoring the Response to Tyrosine Kinase Inhibitor (TKI) Treatment in Chronic Myeloid Leukemia (CML)

The aim of oral tyrosine kinase inhibitor (TKI) treatment in chronic myeloid leukemia (CML) is to get ideal hematological, cytogenetic, molecular responses at the critical time points. The depth of the response obtained with TKI and the time to achieve this response are both important in predicting the prognosis in patients with CML. The high efficacy of the TKI treatment of CML has prompted the need for accurate methods to monitor response at levels below the landmark of CCyR. Quantification of BCR-ABL transcripts has proven to be the most sensitive method available and has shown prognostic impact with regard to progression-free survival. European LeukemiaNet (ELN) molecular program harmonized the reporting of results according to the IS (International harmonization of Scale) in Europe. The aim of this review is to outline monitoring the response to optimal TKI treatment based on the ELN CML 2013 recommendations from the clinical point of view as a physician. Careful cytogenetic and molecular monitoring could help to select the most convenient TKI drug and to optimize TKI treatment. Excessive monitoring may have an economic cost, but failure to optimize TKI treatment may result in CML disease acceleration and death.

Targeted cancer therapy--are the days of systemic chemotherapy numbered?

Targeted therapy or molecular targeted therapy has been defined as a type of treatment that blocks the growth of cancer cells by interfering with specific cell molecules required for carcinogenesis and tumor growth, rather than by simply interfering with all rapidly dividing cells as with traditional chemotherapy. There is a growing number of FDA approved monoclonal antibodies and small molecules targeting specific types of cancer suggestive of the growing relevance of this therapeutic approach. Targeted cancer therapies, also referred to as "Personalized Medicine", are being studied for use alone, in combination with other targeted therapies, and in combination with chemotherapy. The objective of personalized medicine is the identification of patients that would benefit from a specific treatment based on the expression of molecular markers. Examples of this approach include bevacizumab and olaparib, which have been designated as promising targeted therapies for ovarian cancer. Combinations of trastuzumab with pertuzumab, or T-DM1 and mTOR inhibitors added to an aromatase inhibitor are new therapeutic strategies for breast cancer. Although this approach has been seen as a major step in the expansion of personalized medicine, it has substantial limitations including its high cost and the presence of serious adverse effects. The Cancer Genome Atlas is a useful resource to identify novel and more effective targets, which may help to overcome the present limitations. In this review we will discuss the clinical outcome of some of these new therapies with a focus on ovarian and breast cancer. We will also discuss novel concepts in targeted therapy, the target of cancer stem cells.

Imatinib adherence associated clinical outcomes of chronic myeloid leukaemia treatment in Taiwan

BACKGROUND

Since the launch of imatinib, chronic myeloid leukaemia has become a chronic condition requiring costly long-term treatment. Emerging evidence from several short-term studies has raised concerns on the detrimental clinical outcomes and waste of resources associated with poor adherence to imatinib.

OBJECTIVE

This study aims to evaluate the effects of long-term imatinib adherence on clinical treatment responses and mortality.

SETTING

This retrospective cohort study was conducted in a medical centre in southern Taiwan.

METHOD

Chronic myeloid leukaemia patients who were prescribed for more than 1 month of imatinib were identified and their medical charts were reviewed from the first date of imatinib prescription to the last date of medical record or upon patients' death. Patients' basic characteristics, imatinib prescriptions, results of laboratory tests, episodes of imatinib-related side effects and mortality rate were recorded.

MAIN OUTCOME MEASURE

Participants' basic characteristics, medication possession ratio and their mortality rate; the association between the medication possession ratio and treatment responses.

RESULTS

Of the 119 included patients, the mean follow-up time was 3.9 ± 2.9 patient-years and the mean medication possession ratio was 89.7 %. At the 18th month of imatinib treatment, 67.2, 54.3 and 34.5 % patients achieved complete cytogenetic, major molecular and complete molecular responses, respectively. There was a significant difference in the 4-year survival rate between the adherence (n = 87) and non-adherence (n = 32) groups (91 vs. 72 %; p = 0.0076). Logistic regression analysis revealed that imatinib adherence was the only factor that significantly influenced the 18th month complete cytogenetic response [odds ratio (OR) 11.6; 95 % confidence interval (CI) 1.7, 114.7; p = 0.0131] and major molecular response (OR 5.1; 95 % CI 1.1, 26.8; p = 0.0351). Cox regression analysis demonstrated that a medication possession ratio greater than 90 % significantly reduced the mortality risk (hazard ratio 0.1; 95 % CI 0.01, 0.60; p = 0.0118).

CONCLUSION

Chronic myeloid leukaemia patients' long-term adherence to imatinib is significantly associated with the 18th month treatment responses including the cytogenetic response, molecular response and the long-term survival rate in clinical practice.

Chronic myeloid leukemia (CML): association of treatment satisfaction, negative medication experience and treatment restrictions with health outcomes, from the patient's perspective

Background

The availability of the tyrosine-kinase inhibitor (TKI), imatinib, and later introduction of second generation TKIs, dasatinib and nilotinib, have not only improved clinical outcomes of patients with chronic myeloid leukemia (CML), but also provide multiple therapeutic options for CML patients. Despite the widespread use of these oral therapies, little is known about the impact of different treatment regimens on patient-reported outcomes (PROs) among CML patients. The objective of this study was to assess the impact of patient-reported treatment restrictions and negative medication experiences (NMEs) on satisfaction and other health outcomes among patients with CML treated with oral TKIs.

Methods

Participants recruited from survey panels and patient networks in the United States (US) and Europe completed an online questionnaire. Respondents included adults (≥18 years) with chronic-phase CML currently on TKI treatment. Study variables included treatment difficulty (i.e., difficulty in following treatment regimens), CML dietary/dosing requirements, NMEs, and validated PROs assessing treatment satisfaction, health-related quality of life (HRQoL), activity impairment, and non-adherence. Structural equation models assessed associations among variables, controlling for covariates.

Results

303 patients with CML (US n=152; Europe n=151; mean age 51.5 years; 46.2% male) completed the questionnaire. Approximately 30% of patients reported treatment difficulties; treatment difficulty was higher among nilotinib (63.3%) than among dasatinib (2.6%) or imatinib (19.2%) treated patients (p<0.0001). Non-adherence was generally low; however, patients on nilotinib vs. imatinib reported missing doses more often (p<0.05). Treatment satisfaction was associated with significantly increased HRQoL (p<0.05) and lower activity impairment (p<0.01). NMEs were associated with decreased treatment satisfaction (p<0.01) and HRQoL (p<0.05), and greater activity impairment (p<0.01). Higher overall treatment restrictions were associated with greater treatment difficulty (p<0.001), which correlated with non-adherence (p<0.01).

Conclusions

Treatment satisfaction and NMEs are important factors associated with HRQoL among patients with CML. Increased treatment restrictions and associated difficulty may affect adherence with TKIs. Choosing a CML treatment regimen that is simple and conveniently adaptable in patients’ normal routine can be an important determinant of HRQoL and adherence.

Current management of chronic myeloid leukemia with tyrosine kinase inhibitors

The clinical outcomes and survival of tyrosine kinase inhibitor (TKI)-treated patients with chronic myeloid leukemia (CML) have been significantly improved. The aim of this editorial is to outline critical steps of TKI administration practices during the long-term clinical course of CML based on data obtained from randomized clinical trials and international recommendations. The efficacy of TKI treatment, TKI side effects, off-target complications, and long-term morbidities due to both the disease and the drug are common arguments in the management of CML. Complete hematological response, early complete cytogenetic response, faster major molecular response, and deeper, more durable molecular responses (MR4, MR4.5, MR5) are the ultimate goals for TKI-receiving patients with CML.

Conflict of interest:None declared.

Plasma protein binding: from discovery to development

The importance of plasma protein binding (PPB) in modulating the effective drug concentration at pharmacological target sites has been the topic of significant discussion and debate amongst drug development groups over the past few decades. Free drug theory, which states that in absence of energy-dependent processes, after steady state equilibrium has been attained, free drug concentration in plasma is equal to free drug concentration at the pharmacologic target receptor(s) in tissues, has been used to explain pharmacokinetics/pharmacodynamics relationships in a large number of cases. Any sudden increase in free concentration of a drug could potentially cause toxicity and may need dose adjustment. Free drug concentration is also helpful to estimate the effective concentration of drugs that potentially can precipitate metabolism (or transporter)-related drug-drug interactions. Disease models are extensively validated in animals to progress a compound into development. Unbound drug concentration, and therefore PPB information across species is very informative in establishing safety margins and guiding selection of First in Human (FIH) dose and human efficacious dose. The scope of this review is to give an overview of reported role of PPB in several therapeutic areas, highlight cases where PPB changes are clinically relevant, and provide drug metabolism and pharmacokinetics recommendations in discovery and development settings.

Tissue banking, bioinformatics, and electronic medical records: the front-end requirements for personalized medicine

Personalized medicine promises patient-tailored treatments that enhance patient care and decrease overall treatment costs by focusing on genetics and "-omics" data obtained from patient biospecimens and records to guide therapy choices that generate good clinical outcomes. The approach relies on diagnostic and prognostic use of novel biomarkers discovered through combinations of tissue banking, bioinformatics, and electronic medical records (EMRs). The analytical power of bioinformatic platforms combined with patient clinical data from EMRs can reveal potential biomarkers and clinical phenotypes that allow researchers to develop experimental strategies using selected patient biospecimens stored in tissue banks. For cancer, high-quality biospecimens collected at diagnosis, first relapse, and various treatment stages provide crucial resources for study designs. To enlarge biospecimen collections, patient education regarding the value of specimen donation is vital. One approach for increasing consent is to offer publically available illustrations and game-like engagements demonstrating how wider sample availability facilitates development of novel therapies. The critical value of tissue bank samples, bioinformatics, and EMR in the early stages of the biomarker discovery process for personalized medicine is often overlooked. The data obtained also require cross-disciplinary collaborations to translate experimental results into clinical practice and diagnostic and prognostic use in personalized medicine.

Imatinib-induced decompensated heart failure in an elderly patient with chronic myeloid leukemia: case report and literature review

Because it is safe and well tolerated, imatinib is a standard first-line therapy for chronic myeloid leukemia (CML). Although there have been sporadic reports of imatinib-induced cardiotoxicity, including left ventricle (LV) dysfunction and heart failure, the evidence for it is contradictory. Here, we reported a case of an 88-year-old male patient with CML developed decompensated heart failure following imatinib therapy. Four days after the initiation of imatinib, the patient developed orthopnea, edema and a pleural effusion accompanied by abdominal distension, nausea and vomiting. The chest X-ray film showed an enlarged cardiac profile. The echocardiogram demonstrated a decreased LV ejection fraction and enlarged left-side cardiac chambers. B-type natriuretic peptide concentrations were markedly increased. The patient recovered soon after the withdrawal of imatinib and introduction of comprehensive therapy for heart failure. Imatinib-induced cardiotoxicity in elderly patients is a potentially serious complication that merits further evaluation.

Imatinib increases apoptosis index through modulation of survivin subcellular localization in the blast phase of CML cells

Using MTT, Annexin V/flow cytometry, immunocytochemistry, subcellular fractionation, and Western blotting assays we analyzed the effect of imatinib in two blast phase of chronic myeloid leukemia (CML) cell lines: K562 P-glycoprotein (Pgp)-negative, and Lucena, Pgp-positive. In K562 cell line, the high apoptosis index induced by imatinib was associated with the survivin predominantly in the nucleus. In the Lucena cell line, the low apoptosis index induced by imatinib was associated with a cytoplasmatic survivin localization. Pgp and survivin might be subject to the same molecular regulation, and therefore represent a therapeutic target in the blast phase of CML.

Dasatinib for the treatment of chronic myeloid leukemia

Earlier use of more potent tyrosine kinase inhibitors such as dasatinib improves response rates for patients with chronic myeloid leukemia (CML). The SRC-ABL Tyrosine Kinase Inhibition Activity Research Trials series displayed dasatinib efficacy in patients with all phases of CML who are resistant or intolerant to imatinib. More recently, dasatinib has been shown to induce rapid and high rates of response and has gained approval for newly diagnosed patients with CML in chronic phase. The future of CML therapy may incorporate more potent tyrosine kinase inhibitors such as dasatinib into initial treatment for newly diagnosed patients. The ability of dasatinib to induce rapid and high rates of response with a low progression to advanced forms of CML may translate into improvements in survival.

Refractive-index-based screening of membrane-protein-mediated transfer across biological membranes

Numerous membrane-transport proteins are major drug targets, and therefore a key ingredient in pharmaceutical development is the availability of reliable, efficient tools for membrane transport characterization and inhibition. Here, we present the use of evanescent-wave sensing for screening of membrane-protein-mediated transport across lipid bilayer membranes. This method is based on a direct recording of the temporal variations in the refractive index that occur upon a transfer-dependent change in the solute concentration inside liposomes associated to a surface plasmon resonance (SPR) active sensor surface. The applicability of the method is demonstrated by a functional study of the aquaglyceroporin PfAQP from the malaria parasite Plasmodium falciparum. Assays of the temperature dependence of facilitated diffusion of sugar alcohols on a single set of PfAQP-reconstituted liposomes reveal that the activation energies for facilitated diffusion of xylitol and sorbitol are the same as that previously measured for glycerol transport in the aquaglyceroporin of Escherichia coli (5 kcal/mole). These findings indicate that the aquaglyceroporin selectivity filter does not discriminate sugar alcohols based on their length, and that the extra energy cost of dehydration of larger sugar alcohols, upon entering the pore, is compensated for by additional hydrogen-bond interactions within the aquaglyceroporin pore.

Quantitative detection of BCR-ABL fusion gene and its application in monitoring chronic myeloid leukemia treatment

The BCR-ABL fusion gene in chromosome translocation, t (9; 22), and its product, p210BCR/ABL oncogenic tyrosine kinase, is the underlying molecular mechanism that leads to the development of CML. Quantitative detection of BCR-ABL fusion gene has become a reliable approach to diagnose and monitor CML. The aim of this study was to evaluate a Roche t (9; 22) kit in CML diagnosis, monitoring treatment responses, and identification of relapse. Using BCR-ABL fusion gene-expressing K562 cells, a series of standard samples were prepared and used to establish a curve for the calculation of BCR-ABL fusion gene expression in patient samples. Our results indicate that PCR detection system with aforementioned kit has good reproducibility. In addition, the relative concentration of BCR-ABL measured by PCR was in agreement with the patient's response to the Imatinib treatment and bone marrow morphology remission. Furthermore, we found that the relative concentration of BCR-ABL fusion gene increased 1-3 months before CML relapse was clinically and cytogenetically diagnosed, suggesting that the PCR-based BCR-ABL fusion gene detection with t (9; 22) kit is able to diagnose the recurrence of CML at least 1 month earlier than the classic cytogenetic analysis. In conclusion, detection of BCR-ABL fusion gene expression in CML using Roche t (9; 22) kit has great clinical value in the primary diagnosis, monitoring treatment responses, and identification of relapse in CML patients.

Optimizing first-line therapy for patients with chronic myeloid leukemia

Imatinib is now established as the gold standard first-line therapy for patients with chronic myeloid leukemia (CML). Responses to imatinib are superior to those seen with interferon alfa and also occur earlier, demonstrating a stronger and deeper response to therapy. Imatinib therapy also provides long-term clinical benefit and outcomes, with improved progression-free survival (PFS) and overall survival (OS) compared with historical controls, at 6 years of follow-up. Recent data show that annual event rates decline over time with imatinib therapy, suggesting that long-term disease control is possible in continuously responding patients. Despite these treatment successes, new strategies are continually being evaluated to maximize responses to imatinib and ensure the best treatment outcomes for all patients. For example, high-dose imatinib therapy, with doses up to 800 mg/d, has been shown to improve response rates. Prospective, randomized trials are ongoing to assess the benefits of high-dose imatinib therapy and determine whether it extends PFS and OS compared with standard-dose imatinib.

Comparison of temporal changes in psychological distress after hematopoietic stem cell transplantation among the underlying diseases of Japanese adult patients

BACKGROUND

Although hematopoietic stem cell transplantation (HSCT) can potentially cure some hematological malignancies, patients who undergo HSCT experience psychological distress. However, there have been few studies on the short-term influence of HSCT on psychological distress.

METHODS

The subjects were 71 patients with hematological malignancies who underwent HSCT: 33 with acute leukemia, 19 with chronic leukemia, nine with myelodysplastic syndrome, and 10 with malignant lymphoma. Psychological distress was assessed prior to HSCT and on the seventh day after HSCT using the Profile of Mood States (POMS).

RESULTS

With regard to Anger-Hostility, the interaction of time (pre- and post-HSCT) and group (the four groups) was significant in male patients (p = 0.04), but not in female patients. With regard to the other subscales of POMS, there was no significant main effect or interaction in male or female patients.

CONCLUSION

It may be important to provide psychological support to patients throughout the period of HSCT in consideration of differences in mood changes associated with the underlying disease and patient sex in order to provide efficient psychiatric intervention for both better psychiatric and survival outcomes.