By Kim Coghill

Washington Editor

Lilly ICOS LLC said encouraging results from a Phase III study of an erectile dysfunction compound likely mean it will file a new drug application in the second half of the year.

In the Phase III placebo-controlled study of the product, known as Cialis, 85 percent of the patients taking 20 mg doses experienced improved erections, Lilly ICOC said prior to its presentation Saturday at the 96th Annual Meeting of the American Urological Association in Anaheim, Calif. Lilly ICOS LLC is a joint venture between ICOS Corp., of Bothell, Wash., and Eli Lilly and Co., of Indianapolis. The companies in 1998 entered a 50-50 partnership to develop a treatment for sexual dysfunction.

Cialis inhibits PDE5, or phosphodiesterase type 5, an enzyme in smooth muscle that controls the level of cyclic GMP (guanylic acid), much like Pfizer Inc.¿s erectile dysfunction (ED) treatment Viagra. Inhibiting PDE5 increases the level of cyclic GMP, allowing blood vessels to dilate.

Lacy Fitzpatrick, ICOS¿ associate director of investor relations, said the company is pleased to be reporting positive results for its Phase III study in a broad population of men and hopes the drug will be approved for a general population (including diabetes patients) sometime next year.

The side effects are minimal, she said. ¿So far what we¿ve seen in side effects is mild to moderate and it tends to diminish with continued treatment. The dropout rate in the Phase III study is being reported as very low and we¿ve seen no reports of blue vision [visual disturbance that occurs with some patients].¿

The Phase III study looked at the safety and efficacy of ¿on-demand¿ Cialis treatment in 196 men suffering from mild-to-severe ED. Men in the study were randomized to receive up to 20 mg of Cialis or placebo over a 12-week period. Men were free to take their study medication without restrictions on food or alcohol consumption and to have sex with their partners at the time of their choosing after each dose.

Eighty-five percent of men taking 20 mg of Cialis reported significantly improved erections compared with baseline. In addition, 78 percent of intercourse attempts recorded by all men on Cialis 20 mg were successful. Sixty-three percent of men with ED treated with Cialis 20 mg achieved an erectile function score experts consider ¿normal¿ for healthy men as measured by the International Index of Erectile Function (IIEF), a statement released by the company said.

Fitzpatrick said Lilly ICOS LLC is conducting a number of other studies using the compound and among them are two Phase II studies that are scheduled to be discussed at the meeting in Anaheim. In both studies, men reported improved ability to achieve erections up to 24 hours after taking Cialis. The most commonly reported side effects were backaches, muscle aches and upset stomach, the company said.

In the first of two clinical trials, 61 men with mild-to-severe ED were randomized to receive Cialis 10 mg or placebo. Patients in the Cialis group were significantly more successful in achieving erections than men in the placebo group at 24 hours postdose.

In the second trial to measure the onset of responsiveness, 223 men received Cialis up to 20 mg or placebo in a home-based study. The patients took the medication immediately before engaging in sexual activity. In this trial, the ability to achieve an erection after sexual stimulation was statistically superior in the group taking Cialis 20 mg compared with the placebo group at 16 minutes postdosing. Men taking Cialis 20 mg in this study also recorded statistically greater success at second sexual encounters than men on placebo for a period of up to 24 hours.

In April, Lilly ICOS LLC reported positive results in the treatment of men with diabetes-related ED. In a 216-patient, randomized, placebo-controlled trial, 64 percent of treated patients who took the compound reported improved erections, the company said. (See BioWorld Today, April 9, 2001.)

Erectile dysfunction affects an estimated 152 million men and their partners worldwide, with many cases caused by cardiovascular disease and diabetes.

ICOS¿ stock (NASDAQ:ICOS) closed Friday at $62.95, up 60 cents, while Lilly¿s (NYSE:LLY) closed at $86.43, up $1.73.