IDEC Pharmaceuticals Announces Net U.S. Rituxan Sales of $180.0 Million in Second Quarter, 2001

(BW HealthWire) — Following Genentech’s second quarter earnings release, IDEC Pharmaceuticals Corporation (Nasdaq: IDPH) today announced that the collaboration between IDEC and Genentech, Inc. achieved U.S. net sales of Rituxan(R) (Rituximab) totaling $180.0 million for the three months ended June 30, 2001. Based on this level of sales IDEC estimates net income of approximately $0.15 per share on a diluted basis for the second quarter of 2001.

IDEC’s full financial results for the second quarter are expected to be released on July 19, 2001, after the close of market. Following the release, IDEC will conduct a live webcast of a discussion by IDEC management of the financial results between 1:30-2:30 p.m. Pacific Standard Time. The webcast will be accessible through a link at IDEC’s website at http://idecpharm.cdmail.biz and will remain available for 48 hours.

“We continue to be impressed with Rituxan sales in the second quarter,” said William R. Rohn, IDEC’s chief operating officer. “The expanded package insert approved early in the quarter has stimulated our dialogue with medical oncologists on the utility of Rituxan. Net sales for the quarter rose more than 86 percent compared to the same quarter last year and for the first half we are up over 99 percent compared to the first half of last year.”

The net sales of Rituxan reported by Genentech in the second quarter included $7.7 million of ex-US sales to its partner F. Hoffmann-La Roche Ltd. IDEC’s royalty revenue on sales of Rituximab outside the U.S. is based on Roche’s end-user sales and is booked with a one-quarter lag. IDEC will recognize, during the second quarter of 2001, $3.3 million in royalties from Roche’s end-user sales during the first quarter of 2001. 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; in Japan, Roche is partnered with Zenyaku Kogyo for the commercialization of Rituximab.

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: 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, 2000 and Form 10-Q for the quarter ended March 31, 2001 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 and Rituxan are registered U.S. trademarks of the company. The company is headquartered at 3030 Callan Road, San Diego, CA 92121.

IDEC Pharmaceuticals’ press releases are available at no charge through Business Wire’s News on Demand Plus. For a menu of IDEC’s current press 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.

CONTACT: IDEC Pharmaceuticals Corporation Vince Reardon, Director, Corporate Communications 858/431-8656