The department for clinical development is responsible for planning and execution of clinical studies. During the clinical trials the compound is evaluated for its safety and efficacy in treating or preventing a specific disease or condition. The results of these studies will comprise the most important factors in the approval process. The different steps in clinical development are described below.

Phase I
In phase I the compound is administered to humans for the first time. The focus is initial safety and tolerability, as well as uptake, distribution, elimination and metabolism of the drug (PK/PD data) to define a dose range and dose regimen for the phase II studies and to determine the nature of adverse reactions, if any. These studies are performed in healthy volunteers but also in special populations of patients.

Phase II
Phase II is usually the first time patients are exposed to the compound. Phase II is a therapeutic exploratory phase, often divided into phase IIa and IIb. Phase IIa is aimed at proof of principle, showing that the compound has beneficial effects by proving efficacy in a small group of patients with a well defined diagnosis. In phase IIb, the scope is to prepare for the pivotal phase III studies by confirming the dose selection, administration regimen, endpoints, and other information in a wider patient population and for longer duration proof of concept. The study duration can be extended to several months to look at possible tolerance or rebound effects.

Phase III
In pivotal phase III studies a large number of patients are studied to confirm therapeutic benefit and to provide documentation needed for approval of the targeted claims and regulatory purpose. To a large extent, study designs are determined by the level of efficacy seen in phase II studies. Indication or compound-specific issues may need to be ad-dressed, such as head-to-head comparison, combined treat-ment and efficacy in different disease states. For safety and tolerability, general regulatory demands define the number of patients and the exposure time needed for approval.

Once all clinical documentation has been compiled and evaluated, a new drug application (NDA) is submitted to the regulatory authorities.