West Coast Editor

Surging ahead in its march to market with a treatment for hereditary angioedema, Dyax Corp. began patient treatment in the Phase III trial testing DX-88, a kallikrein inhibitor partnered with Genzyme Corp.

"I don't think race' is a word I would use," said Thomas Beck, Cambridge, Mass.-based Dyax's vice president of business and product development, though he acknowledged other firms also are working on late-stage drugs in the indication.

"We're trying to get the best possible therapeutic to patients," he said.

Dyax's stock (NASDAQ:DYAX) closed Thursday at $4.92, up 61 cents, or 14.2 percent, and launch of the pivotal study, known as EDEMA3, triggers a $3 million milestone payment under the terms of the deal signed about two and a half years ago with Genzyme, also of Cambridge. The companies are targeting 2007 for approval in the U.S., followed by clearance in Europe. (See BioWorld Today, June 25, 2003.)

EDEMA3 is taking place at 47 sites in the U.S. and Canada, with more in Europe and Israel.

"It's been a slightly evolving number," Beck said, putting the total worldwide sites at 60. "The non-U.S. piece is operationally being conducted by Genzyme," which has more of a presence overseas, although EDEMA3 is "one trial, and Dyax has the overall responsibility" for it, he said.

The study is intended to confirm DX-88's efficacy against moderate to severe, acute HAE attacks, and will be run in two stages - a double-blind, placebo-controlled part followed by a repeat phase in which all 62 patients get DX-88 at the same 30-mg dose used in the first phase, when they suffer HAE attacks.

After undergoing one treatment in the placebo-controlled half of the study, patients are eligible for the second. Included in EDEMA3 are some patients who've already been exposed to DX-88 in an ongoing open-label trial.

So far, 303 doses of DX-88 have been administered to 109 angioedema patients in previous EDEMA trials, and 428 doses have been administered to 177 people in safety tests.

Last month, specialty pharma firm Kos Life Sciences Inc. entered a deal with Jerini AG, of Berlin, paying 22 million (then about US$27 million) for rights to develop, market and distribute the Phase III compound Icatibant, a bradykinin B2 receptor antagonist, for HAE. (See BioWorld Today, Nov. 8, 2005.)

Another drug in Phase III is New York-based Lev Pharmaceuticals Inc.'s, C1-esterase inhibitor, which started testing in the first quarter of the year. In May, Pharming Group NV, of Leiden, the Netherlands, reported positive results from Phase II/III studies with its C1 inhibitor.

HAE is a rare genetic disease that causes attacks of localized swelling and inflammation.

"These niche indications have become increasingly attractive to emerging companies, and other than emerging companies," Beck said, adding that Genzyme understands "better than anybody" the rewards of developing drugs for those illnesses.

Genzyme also understands the challenges of winning approvals for such compounds, and Beck told BioWorld Today that Dyax is "very well positioned" to reach the market first with DX-88, for which the worldwide market is estimated at 30,000 to 40,000 patients.

DX-88's unique mechanism of action could give it an edge - kallikrein, which the drug blocks, is an enzyme believed responsible for activating molecules that cause HAE's swelling and pain - and the subcutaneously given product can be used "comfortably and safely at home," he said.

HAE drug combinations are unlikely, Beck said, and predicted very little switching between therapies.

"Cocktails? No," he said. "If it ain't broke, don't fix it. These patients are looking for stability in their lives," and will stick with a compound that safely provides relief.

Genzyme's shares (NASDAQ:GENZ) ended the day at $74, up 20 cents.