IDEC Pharmaceuticals Announces Net U.S. Rituxan Sales for 2002: $318.2 Million in Fourth Quarter and $1.08 Billion for the Full Year

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(BUSINESS WIRE) — IDEC Pharmaceuticals Corporation (Nasdaq: IDPH) today announced a preliminary net income estimate of approximately $0.26 per share on a diluted basis for the fourth quarter of 2002 and $0.85 per share on a diluted basis for the full year 2002.

Net income for the three months ended December 31, 2002 was achieved through the combination of U.S. net sales of Rituxan(R) (rituximab), which IDEC copromotes in the U.S. with Genentech, Inc., totaling $318.2 million and U.S. net sales of Zevalin(R) (ibritumomab tiuxetan), which IDEC markets alone in the U.S., totaling $5.5 million. Sales of Zevalin during the quarter were affected by a one week unavailability of yttrium supplies, due to a planned semi-annual preventative maintenance shutdown by MDS Nordion, exclusive yttrium chloride supplier for the Zevalin regimen.

Total U.S. net sales of Rituxan for 2002 were $1.08 billion, compared to $779 million for 2001, an increase of 39 percent from the prior year. For 2002, total U.S. net sales of Zevalin, which was launched in April 2002, were $13.7 million.

Worldwide net sales of Rituxan totaling $346.6 million as reported by Genentech in the fourth quarter of 2002, included $28.4 million of ex-US sales to its partners F. Hoffmann-La Roche Ltd. and Zenyaku Kogyo Co. Ltd. of Japan. IDEC’s royalty revenue on sales of Rituximab outside the U.S. is based on Roche’s and Zenyaku’s end-user sales and is booked with a one-quarter lag. IDEC will recognize, during the fourth quarter of 2002, $13.5 million in royalties from Roche’s and Zenyaku’s end-user sales during the third quarter.

IDEC’s full financial results for the fourth quarter and fiscal year 2002 are expected to be released on January 30, 2003, after the close of market. Following the release, IDEC will host a live webcast of a discussion by IDEC management between 1:30 p.m. and 2:30 p.m. PST. The webcast will be accessible through IDEC’s website at idecpharm.cdmail.biz and will be archived for 10 business days.

Beginning with the financial results for first quarter 2003, IDEC will no longer issue quarterly “flash” financial releases (such as the current release) reporting U.S. net sales of products and an estimate of earnings per share. Future quarterly and annual financial results, including reports of U.S. net sales of IDEC’s products, will be released approximately one to two weeks following the report of Rituxan sales by Genentech. Rituxan was discovered by IDEC and is copromoted in the United States by IDEC and Genentech. Rituxan is jointly developed by IDEC, Genentech Inc., F. Hoffmann-La Roche Ltd. of Switzerland and Zenyaku Kogyo Co. Ltd. of Japan. Roche has marketing rights to Rituximab outside of the United States, and copromotes Rituxan in Japan with Zenyaku Kogyo.

IDEC Pharmaceuticals Corporation is a leader in the discovery, development, and commercialization of targeted immunotherapies for the treatment of cancer and autoimmune diseases. IDEC discovered and developed the first commercially available radioimmunotherapy product (Zevalin) approved in the United States, which is used to treat certain non-Hodgkin’s lymphomas. IDEC also discovered, and with co-promotion partner Genentech, Inc., developed the first monoclonal antibody product (Rituxan) approved in the United States for the treatment of cancer. Rituxan is approved in over 70 countries worldwide and is also used to treat various types of non-Hodgkin’s lymphomas. IDEC is a San Diego based, integrated biopharmaceutical company with multiple products in clinical stage development and strategic alliances involving a variety of research platforms.

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: http://idecpharm.cdmail.biz.

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, 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, 2001 and Form 10-Q for the quarter ended September 30, 2002, 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, Rituxan and Zevalin are registered U.S. trademarks of the company. The company’s headquarters are located at 3030 Callan Road, San Diego, CA 92121.

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CONTACT: IDEC Pharmaceuticals Corporation