West Coast Editor
Vivus Inc. has determined 40 sites where it will enroll patients in a Phase III trial with Alista for female sexual arousal disorder, which afflicts many who are postmenopausal or have undergone hysterectomies - and about 40 percent of the adult population overall.
The company's stock did not react much, probably because Mountain View, Calif.-based Vivus earlier had made public its plan to start the trials about this time, said Leland Wilson, president and CEO. Its shares (NASDAQ:VVUS) closed Tuesday at $4.16, unchanged, after rising to $4.24.
Alista is a proprietary formulation of alprostadil, a synthetic version of the vasodilator prostaglandin E1 (PGE1), applied locally to female genitalia to increase blood flow, engorgement and pleasure.
It's not a pill, like the blockbuster erectile dysfunction drug Viagra, Wilson conceded, but that's at least partly a benefit, noting that Alista gets "a very high response" without an oral medication's systemic exposure. And, he pointed out, there's no alternative for women.
"Pfizer spent a lot of money trying to show that Viagra had some benefit" for women, Wilson noted, but the drug doesn't work for them. "We've had three studies [with Alista], all showing very promising results that have been released at scientific meetings." Lotion-like Alista is easy to apply, he said, and is squeezed through a foam applicator.
Vivus' marketed drug for ED, Muse, uses the same active ingredient.
"Muse is a product that we have been milking ever since the Viagra launch," Wilson told BioWorld Today. The drug sells about $20 million per year, but "Vivus is not about Muse," he said. "It's about four products we have in late-stage development right now."
Among them is avanafil (formerly TA-1790) in Phase II trials for ED. The at-home study begun in April will enroll about 250 patients at 20 sites in the U.S., with data expected in the first half of next year and Phase III trials expected to start in the second half.
Avanafil, like Viagra (sildenafil citrate), is a phosphodiesterase type 5 inhibitor that Vivus licensed in January 2001 from Tanabe Seiyaku Co. Ltd., of Osaka, Japan. The compound features fast action, with good plasma levels in 30 minutes, and a half-life so brief that "we're doing a study looking at being able to take the drug more than once per day" - once for sex in the morning and once in the afternoon, Wilson said.
The short half-life also "solves the issue of having the drug on board for 36 hours," he added, referring to Cialis (tadalafil), the long-lasting PDE5 inhibitor from Lilly ICOS LLC, the joint venture between Bothell, Wash.-based ICOS and Eli Lilly and Co., of Indianapolis.
Although Cialis allows for 36-hour flexibility regarding sex times, it also carries peril if nitrates are administered, as they often are in heart attack emergencies, so "your window from possibly dying from an interaction with nitrates is that long," too, Wilson said.
ED, he noted, "has been called the miner's canary for a major cardiovascular event." When small vessels in the penis are clogged, arteries might be obstructed also.
Also in development is a testosterone spray to improve sexual desire in women, which is expected to enter Phase III trials in the first quarter of next year. A Phase II study is finishing up, Wilson said. If the drugs are approved, Vivus will have the spray for desire problems and Alista for difficulties in arousal.
"People argue back and forth which of these will be bigger [markets], but they'll both be huge," he said, brushing aside claims still made by some that much sexual dysfunction is the result of mental problems.
"All diseases are psychological' until you figure out what's going wrong," he said. "Sex has always been associated with psychiatric kinds of things."
ED was "totally the realm of psychiatrists at one point," Wilson added, but then came Viagra and others. "You'll see that with the female side of the equation, too," he said.
Also on the market from Vivus is Actis, a device designed to enhance erections by slowing venous outflow from the penis. Originally dispensed by prescription only, the device now is available without a prescription.