HAVING LAID FIRM GROUNDWORK for the Bothell biotech's future success, Chairman George Rathmann is stepping down to help other fledgling companies prepare to fly.

Icos reported strong momentum going into 2000 yesterday as it said goodbye to the industry legend who has guided the company for the past 10 years.

Chairman George Rathmann announced he was stepping down from his post yesterday.

He is credited with positioning the Bothell-based company to become one of the nation's top pharmaceutical firms, with a deep pipeline of promising high-tech drugs.

Rathmann said he will spend more time helping develop other young biotech firms, something he accomplished not only with Icos but with California-based Amgen, now the world's biggest biotech company.

Icos' board has named Chief Executive Paul Clark as chairman, effective immediately.

Rathman is known for his methodical, time-consuming approach to developing profitable drugs. His legendary ability to raise capital for research earned him the nickname "Golden Throat" by his colleagues.

In 1990, Rathmann helped assemble a group of investors for Icos that could be considered the Dream Team of venture capital: Microsoft Chairman Bill Gates, former Citigroup Chairman Walter Wriston, former IBM chief Frank Cary, former General Foods President James Ferguson and former U.S. Commerce Secretary Alexander Townbridge.

Led by Gates' $5 million investment, which was followed four years later with $10 million more, Icos raised an industry record $36 million.

Yesterday, the company reported a profit of $4.3 million, or 9 cents a share, for the fourth quarter of 1999 as it pushed ahead with several key drug candidates.

It had a profit of $58.4 million, or $1.22 a share on a diluted basis, for the same period in 1998.

For the year, Icos had a loss of $33.2 million, or 76 cents a share, compared with a profit of $31.3 million, or 67 cents a share, in 1998.

But the loss was less than some analysts had expected.

Icos had $69.3 million in cash as of Dec. 31.

Research and development expenses were up 30.5 percent for last year to $100.5 million, compared with $77 million in 1998, a result of increased spending on clinical trials for the impotence drug IC351, the ischemic-stroke drug LeukArrest, the respiratory-distress treatment Pafase and other products in the pipeline.

Both IC351 and LeukArrest are in late-stage Phase III trials in humans.

Icos is developing the impotence drug through a $75 million joint venture with Eli Lilly. Analysts think the drug, which Rathmann claims is safer and more effective than Pfizer's hugely successful Viagra, could take a substantial chunk out of the multibillion-dollar market owned by Pfizer.

Icos stock was down $1.125, or 3.3 percent, to $32.875 at the close today.