Preclinical research phases

Explorative phase - identifying active hit compounds.

Lead identification - identifying feasible compounds with drugable potential.

Optimization phase - this stage is focused on producing the optimal compound/compound class possessing drug potential. Towards the end of this phase, CDs (candidate drugs) are designated.

IND - Late preclinical development - the final working phase before designated CDs enter clinical studies. This phase is authority regulated and includes extensive safety studies, pharmacokinetics, metabolism studies and is when the first kilogram-scale amounts of the active compound are produced. Applications for regulatory approval for clinical trials of designated CDs are also filed.


Clinical development phases

Phase I - trials of the CD on healthy volunteers, usually involving 20 to 50 individuals. Phase I is divided into two parts. In phase Ia, a single dose is administered to healthy volunteers. Phase Ib is a study where subjects are administered with repeated doses.

Phase II - the first trials on patients suffering from the target disorder. Studies usually encompass 100 to 500 patients, with efficacy and safety assessed. Phase II is also divided into two parts. Phase IIa is intended to demonstrate that the course of the disease can genuinely be influenced. Phase IIb demonstrates the efficacy of various doses on the course of the disease.

Phase III - comparative trials on a large sample of patients to measure efficacy in relation to other treatments, if any exist, as well as safety. Phase III trials are often necessary as documentation before an NDA (New Drug Application).


Last Modified: 06/11/2008