IDEC Pharmaceuticals Prices Public Offering

(BW Healthwire) — IDEC Pharmaceuticals Corporation (Nasdaq:IDPH) today announced the pricing of a public offering of its common stock at a price of $181.81 per share. Based on the market demand, the company also announced that it has increased the number of shares offered from 2,000,000 to 2,600,000. IDEC also granted the underwriters of this offering an option to purchase up to 390,000 additional shares of its common stock to cover over-allotments, if any.

The public offering is being underwritten in the United States by Merrill Lynch & Co., Salomon Smith Barney and Banc of America Securities LLC. Internationally, the offering is being underwritten by Merrill Lynch International, Salomon Smith Barney and Bank of America International Limited. A registration statement relating to these securities has been filed with and declared effective by the Securities and Exchange Commission.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of these securities in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state.

Copies of the final prospectus may be obtained from the Prospectus Department at Merrill Lynch & Co., World Financial Center, 5th Fl., North Tower, New York, NY 10281 or contacting any of the other underwriters.

IDEC Pharmaceuticals focuses on the commercialization and development of targeted therapies for the treatment of cancer and autoimmune diseases. IDEC’s antibody products act chiefly through immune system mechanisms, exerting their effect by binding to specific, readily targeted immune cells in the patient’s blood or lymphatic systems. For a menu of IDEC’s current news releases and quarterly reports or to retrieve a specific release, call (888) 329-2309. On the Internet check the News Center at IDEC’s website:

IDEC Pharmaceuticals’ press releases are available at no charge through Business Wire’s News on Demand Plus.

The statements made in this press release contain certain forward-looking statements that involve a number of risks and uncertainties. Actual events or results may differ from IDEC’s expectations. For example, the timing, success and cost of preclinical research and clinical studies, the timing, acceptability and review periods for regulatory filings, the timing of and ability to obtain regulatory approval of products, such as ZEVALIN, the achievement of future product sales, the level of manufacturing performance and the risk factors listed from time to time in IDEC’s SEC filings including but not limited to its Annual Report on Form 10-K for the year ended December 31, 1999 and Form 10-Q for the quarter ended September 30, 2000, may affect the actual results achieved by IDEC. These forward-looking statements represent the company’s judgment as of the date of this release. The company disclaims, however, any intent or obligation to update these forward-looking statements.

IDEC Pharmaceuticals is a registered U.S. trademark of the company. The company’s headquarters is located at 3030 Callan Road, San Diego, CA 92121.

CONTACT: IDEC Pharmaceuticals Corporation