One day after setting a price range for its pending initial public offering, Voyager Pharmaceutical Corp. and its partner Durect Corp. announced the start of a Phase III program for Memryte to treat Alzheimer's disease.

The companies first joined together in July 2002 to use Cupertino, Calif.-based Durect's Durin drug delivery technology with leuprolide acetate, a product with a well-established safety profile that has been used for 20 years to treat prostate cancer, endometriosis and precocious puberty. Raleigh, N.C.-based Voyager has rights to the drug for the treatment of Alzheimer's disease, which afflicts more than 4 million people in the U.S.

"Back in 1998, Voyager applied for a patent to utilize any compound that reduced serum gonadotropin levels in the human as it relates to the treatment of Alzheimer's disease," said Patrick Smith, the company's president and CEO. "By that patent, we have the rights to leuprolide acetate for Alzheimer's disease."

Memryte is a small, biodegradable implant comprising leuprolide acetate and a polymer. It will be used in the pivotal Phase III program as an adjunctive therapy with acetyl cholinesterase inhibitors (ACIs) to treat the mild to moderate form of the disease. The companies expect to enroll about 1,100 patients in two randomized, double-blind, placebo-controlled trials that will last for 56 weeks.

"Basically, it melts over a two-month period and delivers the active compound that way," Smith told BioWorld Today.

Voyager expects to complete the Phase III trials in late 2007 and file a new drug application with the FDA in 2008.

A Phase I trial established the Memryte implant as generally well tolerated with no serious adverse events in healthy patients. Phase II trials in about 225 Alzheimer's disease patients demonstrated a stabilization of disease and positive trends in those taking the therapy.

"Phase II data actually showed that the Memryte implant is capable of stopping the progression of the disease up to one year in length, which has obviously never been shown before," Smith said. "Also, it's been shown to increase the quality of life, by having it not decline over the same period of time."

ACIs are the most widely prescribed therapy for Alzheimer's disease and include Aricept (donepezil HCL, from Pfizer Inc.); Reminyl (galantamine hydrobromide, from Shire Pharmaceuticals Group plc); Exelon (rivastigmine tartrate, from Novartis AG); and Cognex (tacrine HCL, from First Horizon Pharmaceutical Corp.).

"The best outcome for anything that's currently approved is a slight slowing of the progression, not holding the baseline for more than six to seven months," Smith said, "and then the decline starts on the downward path, similar to where it was when they started."

Alzheimer's disease typically leads to progressive memory loss, impairments in behavior and language, and physical deterioration. The market potential for treatments of the disease is estimated to be more than $10 billion a year.

Under the agreement signed three years ago, Voyager gained rights to commercialize Memryte worldwide, with Durect receiving undisclosed milestone payments, development funding and royalties on product sales. (See BioWorld Today, July 30, 2002.)

Voyager filed for its IPO in September, hoping to raise $129 million to fund the Phase III program. (See BioWorld Today, Sept. 12, 2005.)

On Thursday, the company set its share price range at between $15 and $19 for the 5.9 million shares to be offered, as well as a potential 885,000 shares to cover overallotments. If the IPO is priced at the midpoint, Voyager would raise more than $100 million - more than double the average amount raised ($50 million) by the 25 biotech or specialty pharmaceutical companies that have conducted IPOs this year, according to BioWorld Snapshots. Exercised in full, the overallotment option would add another $15 million in gross proceeds for the company. New York-based WR Hambrecht + Co. is serving as the sole underwriter.

In addition to funding the Phase III Memryte program, proceeds also would go toward research and development of the company's other drug development programs, and to prepare for the commercial launch of Memryte, including establishing a sales and marketing infrastructure. In 2006, Voyager intends to file investigational new drug applications for two preclinical candidates to treat hormone-refractory prostate cancer and brain cancers.

Durect's Durin biodegradable implant technology can deliver drugs for up to six months or more. It is based on the use of biodegradable polymer excipients. The company's platform technologies also include the Saber delivery system, a depot injectable useful for protein and small-molecule delivery; the Oradur sustained-release oral gel-cap technology; the Transdur transdermal technology; and the Microdur biodegradable microparticulates, a microspheres injectable system.

Durect's stock (NASDAQ:DRRX) rose 43 cents Friday to close at $6.88.