New drugs are always being developed to fulfill unmet therapeutic needs or to improve efficacy and reduce toxicity of current therapies. Drug development takes a great deal of time, effort, and money. It is estimated that of approximately 10 000 drugs considered promising in the initial screening assay results, fewer than 10 make it to a clinical trial, and only 2 are eventually approved by the Food and Drug Administration (FDA). Advances in combinatorial chemistry, computer design, and structural biology have accelerated the identification of new targets and drugs, yet the process is still cumbersome and lengthy.
Khandekar J, Khandekar M. Phase 1 Clinical TrialsNot Just for Safety Anymore?. Arch Intern Med. 2006;166(14):1440-1441. doi:10.1001/archinte.166.14.1440