Suboptimal response to or failure of imatinib treatment for chronic myeloid leukemia: what is the optimal strategy?

Poor prognosis of chromosome 7 clonal aberrations in Philadelphia-negative metaphases and relevance of potential underlying myelodysplastic features in chronic myeloid leukemia

Clonal chromosome abnormalities in Philadelphia-negative cells could concern chronic myeloid leukemia patients treated by tyrosine kinase inhibitors. The European LeukemiaNet distinguishes -7/del(7q) abnormalities as a “warning”. However, the impact of clonal chromosome abnormalities, and specifically those of -7/del(7q), in Philadelphia-negative cells on clinical outcomes is unclear and based on case-reports showing morphological dysplasia and increased risk of acute myeloid leukemia, suggesting the coexistence of chronic myeloid leukemia and high-risk myelodysplastic syndrome. The aim of this study was to determine whether the impact of -7/del(7q) clonal chromosome abnormalities in Philadelphia-negative cells on the clinical outcome is different from that of other types of abnormalities, and we argue for an underlying associated high-risk myelodysplastic syndrome. Among 102 chronic myeloid leukemia patients with clonal chromosome abnormalities in Philadelphia-negative cells with more than a median of 6 years of follow up, patients with -7/del(7q) more frequently had signs of dysplasia, a lower cumulative incidence of deep molecular response and often needed further treatment lines, with the consequent impact on event-free and progression-free survival. Morphological features of dysplasia are associated with myelodysplastic syndrome/acute myeloid leukemia mutations and compromise the optimal response to tyrosine kinase inhibitors, irrespectively of the type of clonal chromosome abnormalities in Philadelphia-negative cells. However, mutation patterns determined by next-generation sequencing could not clearly explain the underlying high-risk disease. We hereby confirm the pejorative prognostic value of -7/del(7q) clonal chromosome abnormalities in Philadelphia-negative cells and suggest that myelodysplastic features constitute a warning signal that response to tyrosine kinase inhibitors may be less than optimal.

Variation of Cost among Anti-cancer Drugs Available in Indian Market

INTRODUCTION

Although cancer remains a major health problem all over the world, its treatment is limited by affordability of patients in a developing country like India. Information generated from cost analysis studies will be helpful for both the doctors in choosing the correct medicine for their patients and also for policy makers in successfully utilizing the meager resources that are available.

AIM

The aim of the present observational study was to analyse the price variations of anti-cancer drugs available in India.

MATERIALS AND METHODS

The cost of a particular anti-cancer drug being manufactured by different companies, in the same dose and dosage form, was obtained from latest issue of "Current Index of Medical Specialties" (CIMS) January-April, 2016. The difference between the maximum and minimum prices of various brands of the same drug was analysed and percentage variation in the prices was calculated. The results of the study were expressed as absolute numbers and percentages.

RESULTS

Overall, the price of a total of 23 drugs belonging to 6 different categories available in 52 different formulations were analysed. Among alkylating agents, oxaliplatin (50mg; injection) showed the maximum price variation of 125.02%. In anti-metabolites, methotrexate (2.5mg; tablet) showed the maximum price variation of 75.30%. The maximum price variation among natural products was seen with paclitaxel (260 mg; injection) of 146.98%, among hormonal drugs, was seen with flutamide (250mg; tablet) of 714.24%, among targeted drugs was seen with imatinib mesylate (100mg; film coated tablet) of 5.56% and among supportive drugs, granisetron (1mg; tablet) showed the maximum price variation of 388.68%.

CONCLUSION

The average percentage variations of different brands of the same anti-cancer drug in same dose and dosage form manufactured in India is very wide. The government and drug manufacturing companies must direct their efforts in reducing the cost of anti-cancer drugs and minimizing the economic burden on the patients.

Employing dynamical computational models for personalizing cancer immunotherapy

INTRODUCTION

Recently, cancer immunotherapy has shown considerable success, but due to the complexity of the immune-cancer interactions, clinical outcomes vary largely between patients. A possible approach to overcome this difficulty may be to develop new methodologies for personal predictions of therapy outcomes, by the integration of patient data with dynamical mathematical models of the drug-affected pathophysiological processes.

AREAS COVERED

This review unfolds the story of mathematical modeling in cancer immunotherapy, and examines the feasibility of using these models for immunotherapy personalization. The reviewed studies suggest that response to immunotherapy can be improved by patient-specific regimens, which can be worked out by personalized mathematical models. The studies further indicate that personalized models can be constructed and validated relatively early in treatment.

EXPERT OPINION

The suggested methodology has the potential to raise the overall efficacy of the developed immunotherapy. If implemented already during drug development it may increase the prospects of the technology being approved for clinical use. However, schedule personalization, per se, does not comply with the current, 'one size fits all,' paradigm of clinical trials. It is worthwhile considering adjustment of the current paradigm to involve personally tailored immunotherapy regimens.

Combined Population Dynamics and Entropy Modelling Supports Patient Stratification in Chronic Myeloid Leukemia

Modelling the parameters of multistep carcinogenesis is key for a better understanding of cancer progression, biomarker identification and the design of individualized therapies. Using chronic myeloid leukemia (CML) as a paradigm for hierarchical disease evolution we show that combined population dynamic modelling and CML patient biopsy genomic analysis enables patient stratification at unprecedented resolution. Linking CD34⁺ similarity as a disease progression marker to patient-derived gene expression entropy separated established CML progression stages and uncovered additional heterogeneity within disease stages. Importantly, our patient data informed model enables quantitative approximation of individual patients’ disease history within chronic phase (CP) and significantly separates “early” from “late” CP. Our findings provide a novel rationale for personalized and genome-informed disease progression risk assessment that is independent and complementary to conventional measures of CML disease burden and prognosis.

Multi-agent chemotherapy overcomes glucocorticoid resistance conferred by a BIM deletion polymorphism in pediatric acute lymphoblastic leukemia

A broad range of anti-cancer agents, including glucocorticoids (GCs) and tyrosine kinase inhibitors (TKIs), kill cells by upregulating the pro-apoptotic BCL2 family member, BIM. A common germline deletion in the BIM gene was recently shown to favor the production of non-apoptotic BIM isoforms, and to predict inferior responses in TKI-treated chronic myeloid leukemia (CML) and EGFR-driven lung cancer patients. Given that both in vitro and in vivo GC resistance are predictive of adverse outcomes in acute lymphoblastic leukemia (ALL), we hypothesized that this polymorphism would mediate GC resistance, and serve as a biomarker of poor response in ALL. Accordingly, we used zinc finger nucleases to generate ALL cell lines with the BIM deletion, and confirmed the ability of the deletion to mediate GC resistance in vitro. In contrast to CML and lung cancer, the BIM deletion did not predict for poorer clinical outcome in a retrospective analysis of 411 pediatric ALL patients who were uniformly treated with GCs and chemotherapy. Underlying the lack of prognostic significance, we found that the chemotherapy agents used in our cohort (vincristine, L-asparaginase, and methotrexate) were each able to induce ALL cell death in a BIM-independent fashion, and resensitize BIM deletion-containing cells to GCs. Together, our work demonstrates how effective therapy can overcome intrinsic resistance in ALL patients, and suggests the potential of using combinations of drugs that work via divergent mechanisms of cell killing to surmount BIM deletion-mediated drug resistance in other cancers.

Epidemiological and clinical profile of patients with chronic myeloid leukemia at Health-Care Global, Bangalore Institute of Oncology

Health-Care Global, Bangalore Institute of Oncology is a cancer care center, which provides comprehensive care for cancer patients. Here, we present data of 350 patients diagnosed as cases of chronic myeloid leukemia over a period of 10 years. In our patient population, there was male predominance and majority of patients lied between the age group of 40 and 50 years. 90% patients were initially started on 400 mg dose of imatinib. About 30% of patient population required dose excalation due to inadequate response while 10% required dose descalation due to myelosuppression. 60% of patients had complete response by 3 months and 52% of patients had major molecular response by 1 year.

Report of chronic myeloid leukemia in chronic phase from Eastern India, Institute of Hematology and Transfusion Medicine, Kolkata, 2001-2009

The data 192 patients from Eastern India, Kolkata center was presented in Indian cooperative oncology network meeting, out of which 97% patients were diagnosed in the chronic phase. Complete hematological response was seen in 70.5% among patients and 86% of patients were in clinical and hematological remission over 5 years with a median follow-up of 4.85 years.

Emerging therapeutic strategies for targeting chronic myeloid leukemia stem cells

Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder. Current targeted therapies designed to inhibit the tyrosine kinase activity of the BCR-ABL oncoprotein have made a significant breakthrough in the treatment of CML patients. However, CML remains a chronic disease that a patient must manage for life. Although tyrosine kinase inhibitors (TKI) therapy has completely transformed the prognosis of CML, it has made the therapeutic management more complex. The interruption of TKI treatment results in early disease progression because it does not eliminate quiescent CML stem cells which remain a potential reservoir for disease relapse. This highlights the need to develop new therapeutic strategies for CML to achieve a permanent cure, and to allow TKI interruption. This review summarizes recent research done on alternative targeted therapies with a particular focus on some important signaling pathways (such as Alox5, Hedgehog, Wnt/b-catenin, autophagy, and PML) that have the potential to target CML stem cells and potentially provide cure for CML.

Pushing the limits of targeted therapy in chronic myeloid leukaemia

Tyrosine kinase inhibitor (TKI) therapy targeting the BCR-ABL1 kinase is effective against chronic myeloid leukaemia (CML), but is not curative for most patients. Minimal residual disease (MRD) is thought to reside in TKI-insensitive leukaemia stem cells (LSCs) that are not fully addicted to BCR-ABL1. Recent conceptual advances in both CML biology and therapeutic intervention have increased the potential for the elimination of CML cells, including LSCs, through simultaneous inhibition of BCR-ABL1 and other newly identified, crucial targets.

Dissecting therapeutic resistance to RAF inhibition in melanoma by tumor genomic profiling

A detailed understanding of the mechanisms by which tumors acquire resistance to targeted anticancer agents should speed the development of treatment strategies with lasting clinical efficacy. RAF inhibition in BRAF-mutant melanoma exemplifies the promise and challenge of many targeted drugs; although response rates are high, resistance invariably develops. Here, we articulate overarching principles of resistance to kinase inhibitors, as well as a translational approach to characterize resistance in the clinical setting through tumor mutation profiling. As a proof of principle, we performed targeted, massively parallel sequencing of 138 cancer genes in a tumor obtained from a patient with melanoma who developed resistance to PLX4032 after an initial dramatic response. The resulting profile identified an activating mutation at codon 121 in the downstream kinase MEK1 that was absent in the corresponding pretreatment tumor. The MEK1(C121S) mutation was shown to increase kinase activity and confer robust resistance to both RAF and MEK inhibition in vitro. Thus, MEK1(C121S) or functionally similar mutations are predicted to confer resistance to combined MEK/RAF inhibition. These results provide an instructive framework for assessing mechanisms of acquired resistance to kinase inhibition and illustrate the use of emerging technologies in a manner that may accelerate personalized cancer medicine.