ADME Toxicology Screening

The various developments in initial phases of drug discovery have led to the production of increased number of leads. But it has not impacted the HTS-to-patient pipeline. This is due to the lesser penetration of ADME screening & toxicology studies and because of the labor intensiveness of process involved. R&D Spend: Once a lead optimization project is selected, it is likely to run for 2-3 years and spending between $3 to $6 million. Lack of assessments at the selection stage of leads will increase the R&D spending of big pharmaceutical companies. Industrialization: ADME studies done on a really large scale can factor the unit costs up to 1 in 10th of that done inside a laboratory. Infrastructure required for such industrialization is huge. Apart from huge investments involved, the various issues (apart from technical issues) arising due to industrialization can also be a major hindrance. Moreover, the skills required for this process is more or less that of bulk manufacturing. Wastage of Resources: Scientists are meant for problem solving and usage of them for these purposes leads to wastage of precious resources. Centralization of screening process at the buyerï¾Ãƒâ€šÃ‚Æ’??s facilities may even lead to further cultural and issues related to skill. Failure due to Toxicity Studies is Much More Critical: Both ADME and toxicity, factors about 60% of the total failures of a drug. The weeding out of drugs due to toxicity studies is much more serious than failure due to ADME studies, as the failure occurs at a much later stage of clinical trial. In 1996, 40% of failure of clinical trials in Phase 1 was mainly due to failure of ADME studies and has dropped to 10%, largely due to the advancement in ADME studies. Inculcating more toxicology studies could in fact reduce the failure rates of drugs at a later stage.