New designs in early clinical drug development.

The availability of an unprecedented massive amount of data has provided a magnificent window of opportunity for the development of new drugs. There are currently more drugs in development targeting cancer than any other disease. While this has brought us new waves of drugs, the counterpart is that with these new molecules we have different mechanisms of action, drug kinetics and dynamics, response types and toxicity profiles, which impair classical early clinical trial designs from being effective and efficient. What we once treated as a 'one-size-fits-all' homogeneous disease, has now been uncovered to be a rather heterogeneous condition with multiple targetable mutations. As this generates endless scenarios, it will be impossible to design single 'me-too' trials for every different disease, target, biomarker and agent. To overcome this, we must focus on improving early phase studies, undoubtedly the most critical step from bench to bedside. Goals include decreasing clinical development times, lowering research and development costs and optimizing decisions in advancing through the several phases with a higher degree of certainty in exchange for less failed attempts. We need more informative and, really, transformative early phase designs that seek to obtain the typical late phase objectives in a time continuum and to allow for more robust and efficient go/no-go decisions. With this in mind, different classes of drugs seem to fit with different designs, which present solutions to the different challenges that they pose after finding the maximum tolerated dose/optimum biological dose. This article reviews these concepts and designs and how they can adapt to this new reality in early phase investigation.