History of the development of tadalafil
The Bothell, Washington-based pharmacologic research company ICOS Corporation was started in 1990, and it began the initial cardiovascular testing of a PDE5 inhibitor called IC351 in 1993. Meanwhile, sildenafil citrate (sildenafil) was discovered to cause improved erectile function as a side effect in a trial testing its efficacy for the treatment of angina pectoris in 1994. IC351 was patented that year, and phase I clinical trials began in 1995. Two years later, phase II clinical trials began on patients with ED.
The same year that the FDA approved sildenafil as the first PDE5 inhibitor for the treatment of ED, Eli Lilly and Company joined the ICOS Corporation to form Lilly ICOS LLC in 1998 to expand the marketing venture of the newest PDE5 inhibitor. Tadalafil was officially born in the year 2000 when a new drug application was put forth for IC351 with the generic name tadalafil and trade name Cialis.
In May 2002, the first reports regarding the efficacy and duration of action of tadalafil for ED were presented at the 97th Annual Meeting of the American Urological Association (AUA) in Orlando, Florida, USA. Brock and colleagues presented their initial data supporting the efficacy and safety of canadian tadalafil, and Porst and colleagues presented that tadalafil is efficacious for up to 36 hours. Brock’s data were published later that year in a landmark integrative analysis of five randomized controlled trials of tadalafil that ultimately led to the approval of the drug. Tadalafil was approved for use in Europe in late 2002, and on November 21, 2003, tadalafil was approved by the FDA for use in the United States.