Lilly ICOS' Cialis shows little effect in women

Lilly ICOS, the joint venture between Eli Lilly and ICOS, has announceddisappointing results from a trial of its new phosphodiesterase-5 inhibitor Cialis (IC351), which was designed to evaluate the efficacy and safety of the drug at a range of doses as a therapy for female sexual arousal disorder.

During the trial, premenopausal women received up to 20mg of Cialis or placebo on-demand. They were evaluated using diary reports and the Female Sexual Function Index questionnaire, to assess the change from baseline in sexual functioning. The results showed that, although the drug was well-tolerated, there was no conclusive treatment effect relative to placebo. Similar negative results have been presented for Pfizer's Viagra (sildenafil) in female sexual dysfuntion (Marketletter March 15, 1999).

Cialis is also being evaluated as a potential treatment for male erectile dysfunction. Lilly ICOS recently reported more promising results from a Phase III study of the drug in this indication (Marketletter June 11), and is aiming to submit a New Drug Application to the US Food and Drug Administration later this year.