Disease progression in some cancers may be due to low blood levels of targeted therapies

A Team-based Assignment to Integrate Basic Science and Pharmacotherapeutic Principles for Anticancer Agents

Objective. To implement and evaluate an active-learning, team-based assignment centered on anticancer agents for the integration of basic science and pharmacotherapeutic principles. Methods. Student teams were assigned a specific anticancer agent and were expected to answer a series of questions on the written section of the assignment, followed by a presentation to the class. Each assignment was assessed using a grading rubric that was mapped to the 2013 CAPE educational outcomes. Student perceptions of the assignment were assessed using a short survey. Results. Student cohort performance on the assignment was in the B range (83%) with a mean of 33.2 out of 40. Using the grading rubric, the 12 student cohorts performed particularly well under professionalism (Domain 4.4) that focuses on personal and professional development from CAPE 2013 with means >4 on a 1-5 scale. Student impressions of the assignment suggested that students believed the assignment had a positive effect on their learning and should be continued. Conclusion. The assignment provided a focused review of basic science and pharmacotherapeutic principles and enabled integration of concepts relating to the therapeutic application of anticancer agents, and management of anticancer agent mediated adverse effects. The assignment could contribute toward preparing students for the evolving role of the pharmacist in the management of cancer.

Correlations between imatinib pharmacokinetics, pharmacodynamics, adherence, and clinical response in advanced metastatic gastrointestinal stromal tumor (GIST): an emerging role for drug blood level testing?

Imatinib is the standard of care for patients with advanced metastatic gastrointestinal stromal tumors (GIST), and is also approved for adjuvant treatment in patients at substantial risk of relapse. Studies have shown that maximizing benefit from imatinib depends on long-term administration at recommended doses. Pharmacokinetic (PK) and pharmacodynamic factors, adherence, and drug-drug interactions can affect exposure to imatinib and impact clinical outcomes. This article reviews the relevance of these factors to imatinib's clinical activity and response in the context of what has been demonstrated in chronic myelogenous leukemia (CML), and in light of new data correlating imatinib exposure to response in patients with GIST. Because of the wide inter-patient variability in drug exposure with imatinib in both CML and GIST, blood level testing (BLT) may play a role in investigating instances of suboptimal response, unusually severe toxicities, drug-drug interactions, and suspected non-adherence. Published clinical data in CML and in GIST were considered, including data from a PK substudy of the B2222 trial correlating imatinib blood levels with clinical responses in patients with GIST. Imatinib trough plasma levels < 1100 ng/mL were associated with lower rates of objective response and faster development of progressive disease in patients with GIST. These findings have been supported by other analyses correlating free imatinib (unbound) levels with response. These results suggest a future application for imatinib BLT in predicting and optimizing therapeutic response. Nevertheless, early estimates of threshold imatinib blood levels must be confirmed prospectively in future studies and elaborated for different patient subgroups.

Targeted therapies in the treatment of GIST: Adverse events and maximising the benefits of sunitinib through proactive therapy management

BACKGROUND AND OBJECTIVES

The introduction of targeted therapies has led to improved clinical outcomes in patients with unresectable gastrointestinal stromal tumours (GIST). The receptor tyrosine kinase (RTK) inhibitor imatinib mesylate has been approved as the first-line choice of therapy for this group of patients, while the RTK inhibitor, sunitinib malate, has been approved for the treatment of GIST after disease progression or intolerance to imatinib. Here we discuss and compare the tolerability profiles of imatinib and sunitinib based on published clinical trial data. We also review available data on the potential mechanisms by which these agents may cause adverse events (AEs) and we propose some general strategies to help clinicians to optimise treatment benefit with these agents.

FINDINGS

While the toxicity profiles of imatinib and sunitinib are well known, the mechanisms of toxicity of these agents have yet to be elucidated fully. Clinical observations along with retrospective and prospective analyses suggest that some RTK inhibitor-related AEs have a higher incidence than previously reported from clinical trials. In addition, with greater use, new and unexpected AEs are emerging. Clinicians need to be familiar with the toxicity profiles of RTK inhibitors as well as individual patient risk factors in order to optimise treatment benefit.

CONCLUSIONS

Imatinib and sunitinib are generally well tolerated with known and manageable AE profiles. Proactive therapy management strategies can enable treatment optimisation and allow patients to continue treatment with minimal interruption.

Evaluation and validation of diagnostic tests for guiding therapeutic decisions

The term "theranostics" characterizes a particular combination of the coupled use of a drug therapy with a diagnostic test (called "companion diagnostics"). The diagnostic test marks out the technical means used to identify a biomarker which allows for adjusting the use of the new drug.Theranostics promise a significant step forward for the use of personalized medicine, better tailored for patients in terms of efficacy and tolerance. The development process of theranostics is complex since it requires a proper phasing from development to reimbursement, through a collaborative and controlled approach.The task force's recommendations should form the basis for reflection and action amongst the different players in the field of the development of theranostics.All stages of the system meeting heterogeneous and asynchronous rules should be harmonized to allow for simultaneous availability of, and access to the drug and test. Nevertheless, it is necessary to simplify the regulations to enable a better adaptation of theranostics to the speed of innovation.