Warfarin is one of the best known case studies for pharmacogenetics - where variations in an individual's genome affects his or her response to drugs or other substances. Warfarin is an anti-coagulant often prescribed to relieve blood clots that result in embolism, stroke, or heart attacks. It is very effective at the right dosage, however, it is extremely difficult to dose and the wrong dosage can have very dire consequences. After decades of research, it is clear that personal genetics are at the root of the response variability, and warfarin is poised be the first widely used drug to carry an FDA recommendation for dosing based on pharmacogenetic testing.
Despite widespread acknowledgment of warfarin's pharmacogenetic factors, the road to clinical acceptance has been long. Some of the main challenges are devising an effective dosing scheme given pharmacogenetic data and demonstrating improved clinical outcome as a result of using that dosing scheme. It now appears that we are nearing the final push, with the creation of the International Warfarin Pharmacogenetics Consortium (IWPC). Hosted by the PharmGKB, it is a global collaboration between warfarin scientists sharing data and research to study the relationship between individual genetic variability and dosing response. Anyone with paired genotype and clinical data can join the consortium with the condition that their data is made available to other members of the consortium. When the results of the collaboration are published, it will be authored by the IWPC, and the pooled data will be made available to all those with accounts on PharmGKB.
The IWPC is an interesting and important development. Although it is not completely open, it is most certainly open to those with something to contribute, and will be made open to pharmacogenomics researchers on PharmGKB (detailed data requires an account, due to privacy issues surrounding clinical data). It is also an example of a group of researchers working on the same problem (relating warfarin dosing and response to genotypes) coming together in what has the potential to change current medical practice. Pharmacogenomics has been on the brink for so long, and the IWPC may very well provide the breakthrough that it needs to deliver on the promise of translational research.
Disclaimer: The information presented here is my own recollection of a talk given by Russ Altman at the annual Stanford Biomedical Informatics retreat. For detailed information, you are encouraged to email PharmGKB.