By Mary Welch

InterMune Pharmaceuticals Inc. made an impressive debut Friday on Nasdaq as it sold 6.25 million shares at $20 each in an initial public offering, raising $125 million.

InterMune's stock (NASDAQ:ITMN) closed Friday at $25, up $5.

The Palo Alto, Calif.-based company initially had proposed selling 5 million shares at between $14 and $16 each, and later raised it to the $17 to $19 range. In the end, it upped the price to $20 and the number of shares by 1.25 million. (See BioWorld Today, Feb. 4, 2000, p. 1.)

The company has more than 21 million shares outstanding.

In addition, the company granted the underwriters an option to purchase another 937,000 shares to cover overallotments. The offering was led by Warburg Dillon Read LLC, of New York. Other underwriters were Chase H&Q and Prudential Vector Healthcare Group, both of New York.

InterMune will use the proceeds to commercialize new antibacterial and antifungal drugs for the prevention and treatment of pulmonary and infectious diseases. It currently markets Actimmune (interferon gamma-1b injection) in the U.S. for the treatment of chronic granulomatous disease.

In August, it filed a supplemental biologics license application for the treatment of a second congenital disorder, osteopetrosis. The company is also looking at other indications, several of which are in mid- or advanced-stage clinical trials. It intends to start a Phase II/III pivotal trial during the first half of this year for idiopathic pulmonary fibrosis.

In all, the company said the U.S. market potential for Actimmune for all indications is as much as $3.5 billion per year.

Inteferon gamma-1b, the active ingredient in Actimmune, is a human protein that plays a key role in preventing the formation of excessive scar, or fibrotic, tissue and is a potent stimulator of the immune system.

InterMune, which was formed in 1998 and began operations as a wholly owned subsidiary of Palo Alto, Calif.-based Connetics Corp., posted a 1999 net loss of $6.2 million. As of Dec. 31, it had $4.2 million in cash.