IDEC Pharmaceuticals Announced Oncologic Drugs Advisory Committee to Review ZEVALIN Radioimmunotherapy On September 11, 2001

(BW HealthWire) — IDEC Pharmaceuticals (Nasdaq:IDPH) announced today that ZEVALIN(TM) (Ibritumomab Tiuxetan), an investigational agent for the treatment of relapsed or refractory, low grade, follicular, CD20-positive transformed, B-cell non-Hodgkin’s lymphoma (NHL) and Rituximab-refractory follicular NHL, is to be reviewed by the Oncologic Drugs Advisory Committee (ODAC) of the U.S. Food and Drug Administration (FDA) on September 11, 2001.

The company submitted the Biologics License Application (BLA) for ZEVALIN to the FDA on November 1, 2000 for marketing approval. The FDA accepted the BLA for filing in late December 2000. The company received a Complete Review Letter from the FDA in early May 2001. On July 12, 2001, IDEC announced it had recently submitted documentation and analysis to the FDA’s Center for Biologics Evaluation and Research in response to the FDA’s Complete Review Letter. If approved, ZEVALIN would be the first or one of the first radioimmunotherapies available for commercial use in the United States.

“We are delighted to have the opportunity to appear before the ODAC meeting in September,” said William H. Rastetter, chairman, chief executive officer and president of IDEC Pharmaceuticals. “This is one more major step in the regulatory review process for ZEVALIN.”

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 system. 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:

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, 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. ZEVALIN is a trademark of the company. The company’s headquarters is located 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:

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