PREVIEW-Drugmaker or licensor: HAE drug holds the key for Dyax

* Analysts divided on FDA approval of co's HAE drug

* Safety remains a hurdle to approval

* FDA deadline to rule on drug -- March 23

By Anand Basu

BANGALORE, March 11 (Reuters) - Whether Dyax Corp (DYAX.O) can transform itself into a drugmaker from a pure-play licensing firm, rests on a critical regulatory decision due this month on its experimental drug for a rare genetic disease.

The company is going it alone on commercializing its drug for treatment of hereditary angioedema (HAE) in the United States, as the potentially fatal disease that afflicts about 1 in 10,000 people, is rare enough to be marketed by a small sales team.

The U.S. Food Drug and Administration has set a March 23 deadline to rule on the drug, ecallantide. If approved, it would be the first treatment in the United States for acute attacks of HAE.

The disease is characterized by inherited protein deficiency that causes painful swelling of the skin, intestine, mouth and throat. Ecallantide works by suppressing the enzyme kallikrein that plays a role in the swelling.

Analysts have mixed views on the future of the drug, especially after an FDA advisory panel, which narrowly recommended approval last month, raised concerns about its safety.

On Feb. 4, the panel voted 6 to 5 -- with 2 abstentions -- to urge the FDA to allow sales of the drug, despite a majority voting against the drug's safety profile due to concerns of anaphylaxis, an extreme allergic reaction.

"The FDA is likely to be more lenient on the safety aspect as long as the drug is efficacious," Wedbush PacGrow LifeSciences analyst Kimberly Lee said.

Lee said the safety issues related to ecallantide are manageable as the drug would be administered in a hospital in the presence of physicians who are familiar with its side effects.

Cowen & Co analyst Phil Nadeau, who gives ecallantide a 70 percent chance of winning approval, said the company is moving closer to resolve the issues related to the safe use of the drug.

However, others aren't so sure.

"The panel raised significant issues relating to the safety profile, thus we believe that a near-term approval is unlikely," Needham & Co analyst Mark Monane wrote in a recent note.

Monane, however, said further discussion between the FDA and the company may lead to a more favorable decision in the long term, and a 2009 launch date remains a possibility.