National Editor

With Phase III data from its product candidate for opiate-induced constipation expected by year's end, Progenics Pharmaceuticals Inc. priced a public offering of 3.25 million shares at $16.25 each, for net proceeds of about $48.9 million.

Tarrytown, N.Y.-based Progenics said it intends to use the proceeds for working capital and general corporate purposes.

"The main project is MNTX [methylnaltrexone]," the opioid antagonist in-licensed from the University of Chicago in 2001, being studied in three formulations for three patient populations, said Richard Krawiec, Progenics' vice president of investor relations and corporate communications. (See BioWorld Today, Oct. 2, 2001.)

The company's stock (NASDAQ:PGNX) dipped 14 cents Friday to close at $16.26.

MNTX is being developed as a subcutaneous drug for patients with advanced medical illnesses treated with opioids for pain.

"It's a very fast-acting drug," Krawiec said, with a good safety profile, since MNTX is not metabolized but "excreted whole in the feces and urine. It knocks opioids off the receptors, but it can't get into the brain."

Many hospice patients taking opioids have difficulty swallowing and are not eating well, he noted, so the subcutaneous route is just right for them. The second version is intravenous drip, for treating post-operative ileus (decreased or stopped bowel motility), in which a quick administration is important and patients are allowed to take nothing by mouth, he said. MNTX's third version is oral, for patients getting opioids for chronic pain.

Furthest along is the subcutaneous formulation for AMI, now in Phase III trials with a second Phase III study to begin before the end of the year. Thanks to the drug's prompt action, "we think it has the potential to change the way medicine is done in the hospice," Krawiec told BioWorld Today. "Nobody wants to have to give an emergency enema or digitally disempact someone at three in the morning."

The University of Chicago studied MNTX extensively before Progenics took it over, and a particularly impressive proof-of-concept study was published in the Journal of the American Medical Association in 2000, Krawiec said.

In the study, 22 chronic opioid users with constipation - one bowel movement per week - were studied. Eleven were given intravenous placebo and had no bowel movements in two days. Another 11 got MNTX by IV push. On the first day, 10 out of 11 had bowel movements; the final patient got results on the second day. Responses came as quick as three minutes.

Krawiec said Progenics expects to file a new drug application next year for the subcutaneous version of MNTX, with NDAs following in 2005 and 2006 for the IV drip and oral forms, respectively.

"We're in discussions with multiple potential partners," he added.

Progenics also aims to use the money for general corporate purposes, ramping up its work in prostate cancer and HIV, as well as developing in-house biomanufacturing capacity, he said.

In HIV, the company has PRO 542 multidose Phase II studies expected to finish in the first half of next year. The fusion protein is a monoclonal antibody that blocks the initial attachment of HIV to the cell and has been shown to be synergistic with Fuzeon (enfuvirtide), the HIV drug from Trimeris Inc., of Durham, N.C., and F. Hoffmann-La Roche Ltd., of Basel, Switzerland.

The drugs would "not necessarily [be used together], but it's certainly an option," Krawiec said, noting that "one plus one tends to equal three when you combine these in laboratory settings."

Also in HIV, Progenics has PRO 140, a humanized monoclonal antibody that inhibits viral binding to the CCR5 receptor, for which it expects to file an investigational new drug application this year, with clinical trials starting early next year.

HIV work in general got a boost this fall when the National Institute of Allergy and Infectious Diseases divided $64.3 million in development funds among companies conducting research related to HIV vaccines, and Progenics took $28.6 million. (See BioWorld Today, Sept. 30, 2003.)

The company ended the third quarter with cash, cash equivalents and marketable securities of $22.5 million. Add that to the $28.6 million from the government and the $48.9 netted in the latest stock sale, and Progenics, with 110 employees, is sitting pretty.

"We've been very frugal," Krawiec said. "This is only the second time we've gone to The Street [after its $14 million IPO in 1997]." The first time was in 1999, when the firm raised $41.1 million through a stock sale.

The company's net burn since its inception is only $60 million, Krawiec said.

In the current offering, Progenics has granted underwriters an option to buy another 487,500 shares of common stock. All New York-based, they include joint lead managers Citigroup and CIBC World Markets Corp., with co-managers Lazard; Legg Mason Wood Walker; and Punk, Ziegel & Co.