DARPA is soliciting innovative research proposals to develop an in vitro platform of human tissue constructs that accurately predicts the safety, efficacy, and pharmacokinetics of drug/vaccine candidates prior to their first use in man. Alternative testing methods that rely on isolated human cells hold the promise of authentic human responses to candidate drugs, vaccines, and biologics. Recent research has shown that three-dimensional constructs of one or more cell types are able to reproduce relatively authentic human tissue and organ physiology in an in vitro environment. As a result, DARPA seeks in vitro platforms comprised of human tissue constructs that will accurately assess efficacy, toxicity, and pharmacokinetics in a way that is relevant to humans and suitable for regulatory review. See Attached DARPA-BAA-11-73.