Repurposing old drugs in oncology: Opportunities with clinical and regulatory challenges ahead.

WHAT IS KNOWN AND OBJECTIVE: In order to expedite the availability of drugs to treat cancers in a cost-effective manner, repurposing of old drugs for oncological indications is gathering momentum. Revolutionary advances in pharmacology and genomics have demonstrated many old drugs to have activity at novel antioncogenic pharmacological targets. We decided to investigate whether prospective studies support the promises of nonclinical and retrospective clinical studies on repurposing three old drugs, namely metformin, valproate and astemizole. METHODS: We conducted an extensive literature search through PubMed to gather representative nonclinical and retrospective clinical studies that investigated the potential repurposing of these three drugs for oncological indications. We then searched for prospective studies aimed at confirming the promises of retrospective data. RESULTS AND DISCUSSION: While evidence from nonclinical and retrospective clinical studies with these drugs appears highly promising, large scale prospective studies are either lacking or have failed to substantiate this promise. We provide a brief discussion of some of the challenges in repurposing. Principal challenges and obstacles relate to heterogeneity of cancers studied without considering their molecular signatures, trials with small sample size and short duration, failure consider issues of ethnicity of study population and effective antioncogenic doses of the drug studied. WHAT IS NEW AND CONCLUSION: Well-designed prospective studies demonstrating efficacy are required for repurposing old drugs for oncology indications, just as they are for new chemical entities for any indication. Early and ongoing interactions with regulatory authorities are invaluable. We outline a tentative framework for a structured approach to repurposing old drugs for novel indications in oncology.

Evolution of the Development of Core Competencies in Pharmaceutical Medicine and Their Potential Use in Education and Training.

The evolution of postgraduate vocational education and training in pharmaceutical medicine is described alongside the growth of this scientific-medical discipline and profession for the development of new medicines. Over the past 50 years, whilst the training of competent professionals for their work has been paramount, this has paralleled the need to engage with the rapid and complex changes in R&D technologies, patient and healthcare system needs, and the ethical and regulatory obligations applied to the development of medicines throughout their lifecycle. The move from unstructured training to formal programs with syllabus, curricula and assessments for certification, has been accompanied by educational changes to outcomes-based, learner-centered, competency-based programs. The evolution of education and training along with the development of the set of 57 core competencies for professional practitioners in pharmaceutical medicine are described within the competence framework of seven domains: discovery of medicines and early development; clinical development and clinical trials; medicines regulation; drug safety and surveillance; ethics and subject protection; healthcare marketplace; communication and management. The application of the core competencies in a harmonized, international platform of education and training in medicines development at the undergraduate, postgraduate and continuing professional development levels would invigorate the potential for having a competent workforce with the intent to provide faster access to better and appropriate medicines for patients worldwide.

Withdrawal of prenylamine: perspectives on pharmacological, clinical and regulatory outcomes following the first QT-related casualty.

Prenylamine, an antianginal agent marketed since early 1960, became the first casualty of QT interval related proarrhythmias in 1988 when it was withdrawn from the market. The period of its synthesis and marketing is of particular interest since it antedated, first, any serious clinical safety concern regarding drug-induced prolongation of the QT interval which was, in fact, believed to be an efficient antiarrhythmic mechanism; second, the first description of torsade de pointes as a unique proarrhythmia, typically associated with prolonged QT interval; and third, the discovery and recognition of calcium antagonism as an important cardiovascular therapeutic strategy. This review, 30 years almost to the day following its withdrawal, provides interesting perspectives on clinical, pharmacological and regulatory outcomes that followed. Prenylamine underscored torsadogenic potential of other early antianginal drugs on the market at that time and identified QT-related proarrhythmias as a much wider major public health issue of clinical and regulatory concern. This resulted in various guidelines for early identification of this potentially fatal risk. Application of these guidelines would have readily identified its proarrhythmic potential. Prenylamine also emphasized differences in drug responses between men and women which subsequently galvanized extensive research into sex-related differences in pharmacology. More importantly, however, investigations into the mechanisms of its action paved the way to developing modern safe and effective calcium antagonists that are so widely used today in cardiovascular pharmacotherapy.

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