Integrative oncology drug discovery accompanied by preclinical translational research as prerequisite for clinical development.

The molecular heterogeneity of cancer calls for individualized therapies to become the standard of care. It is now generally accepted that target-specific compounds require specific new development programs. But, even for new drugs with general mode of action (i.e., chemotherapy), tailored treatment approaches, such as specific schedules or combinations, have been shown to improve the therapeutic outcome. Therefore, the preclinical development of new therapeutic agents needs, next to the "classical pharmacodynamic studies", the implementation of integrative translational research (TR) as early as possible. New TR approaches, starting already at target identification and validation (TIV) will allow to defining the optimal patient population for clinical development, to tailor individual treatment of the tumor disease and to choose a rational basis among the manifold options for treatment combinations. We will discuss several examples from TR studies, which have initially been started to evaluate the molecular mode of action and to recognize mechanisms which can lead to resistance. Research was extended later to identify predictive response biomarkers and establish a rationale for combination with different therapies. A detailed gene expression analysis of lung cancer cells and apoptotic pathway interference studies in colon cancer cells provided insight in the molecular mechanisms of action. These new findings are correlated with results from other studies performed during the preclinical development program. We discuss pros and cons, successes and failures of our integrative preclinical development program and provide recommendations for future oncology projects.