Early toxicity screening strategies.

Despite a steady increase in the total amount spent on pharmaceutical R&D over the past decade, the number of new drug approvals has declined in recent years. Toxicity continues to account for more than 30% of compound attrition during the drug development process and remains one of the major causes for drugs to be withdrawn after approval. Since R&D costs increase exponentially along the drug development timeline, late stage failures are heavily contributing to an unsustainable business model for the pharmaceutical industry. Improved early identification of toxicities associated with new drug entities will allow resources to be focused only on those compounds most likely to succeed.