Academic drug discovery: Challenges and opportunities.

There are many different approaches to drug discovery in academia, some of which are based broadly on the industrial model of discovering novel targets and then conducting screening within academic drug discovery centres to identify hit molecules. Here we describe our approach to drug discovery, which makes more efficient use of the capabilities and resources of the different stakeholders. Specifically, we have created a large portfolio of drug projects and conducted small amounts of derisking work to ensure projects are investment ready. In this feature we will describe this model, including its limitations and advantages, since we believe the ideas and concepts will be of interest to other academic institutions and consortia.

Understanding drug targets: no such thing as bad news.

How can small-to-medium pharma and biotech companies enhance the chances of running a successful drug project and maximise the return on a limited number of assets? Having a full appreciation of the safety risks associated with proposed drug targets is a crucial element in understanding the unwanted side-effects that might stop a project in its tracks. Having this information is necessary to complement knowledge about the probable efficacy of a future drug. However, the lack of data-rich insight into drug-target safety is one of the major causes of drug-project failure today. Conducting comprehensive target-safety reviews early in the drug discovery process enables project teams to make the right decisions about which drug targets to take forward.

Reducing attrition in drug development: smart loading preclinical safety assessment.

Entry into the crucial preclinical good laboratory practice (GLP) stage of toxicology testing triggers significant R&D investment yet >20% of AstraZeneca's potential new medicines have been stopped for safety reasons in this GLP phase alone. How could we avoid at least some of these costly failures? An analysis of historical toxicities that caused stopping ('stopping toxicities') showed that >50% were attributable to target organ toxicities emerging within 2 weeks of repeat dosing or to acute cardiovascular risks. By frontloading 2-week repeat-dose toxicity studies and a comprehensive assessment of cardiovascular safety, we anticipate a potential 50% reduction in attrition in the GLP phase. This will reduce animal use overall, save significant R&D costs and improve drug pipeline quality.

Epigenetics and cancer: implications for drug discovery and safety assessment.

It is necessary to determine whether chemicals or drugs have the potential to pose a threat to human health. Research conducted over the last two decades has led to the paradigm that chemicals can cause cancer either by damaging DNA or by altering cellular growth, probably via receptor-mediated changes in gene expression. However, recent evidence suggests that gene expression can be altered markedly via several diverse epigenetic mechanisms that can lead to permanent or reversible changes in cellular behavior. Key molecular events underlying these mechanisms include the alteration of DNA methylation and chromatin, and changes in the function of cell surface molecules. Thus, for example, DNA methyltransferase enzymes together with chromatin-associated proteins such as histone modifying enzymes and remodelling factors can modify the genetic code and contribute to the establishment and maintenance of altered epigenetic states. This is relevant to many types of toxicity including but not limited to cancer. In this paper, we describe the potential for interplay between genetic alteration and epigenetic changes in cell growth regulation and discuss the implications for drug discovery and safety assessment.