Data On IDEC-114, an Investigational Antibody, for Patients With Relapsed or Refractory, Follicular Non-Hodgkin’s Lymphoma Presented At American Society of Hematology Conference

(BUSINESS WIRE) — IDEC Pharmaceuticals Corporation (Nasdaq: IDPH) today announced results of an investigational Phase I/II, dose-escalating study of IDEC-114 in patients with relapsed or refractory, follicular non-Hodgkin’s lymphoma at a presentation of the 44th Annual American Society of Hematology (ASH). IDEC-114 is a monoclonal antibody that targets CD80, an immune costimulatory molecule that is routinely expressed at low levels on the surface of follicular lymphomas and other lymphoid malignancies.

Therapy consisted of intravenous (IV) infusions of IDEC-114 (125 mg/m2, 250 mg/m2, or 375 mg/m2) once a week for four weeks. Data are available on the first 22 patients with a median follow-up of 2 months (range of follow up: 1 to 8 months). Tumor burden reductions have been observed at all doses, including a 19% objective response rate (ORR) at 375 mg/m2 (3 complete responses and no partial responses in 16 patients). A complete response (CR) is achieved in a clinical trial when disease is no longer detectable. In addition, there were no dose-limiting toxicities or serious adverse events (Grade 3 or 4), with the most commonly reported adverse events being fatigue in 26 percent of patients and nausea in 9 percent of patients. Ongoing studies are evaluating higher doses of the antibody (500 mg/m2 per week for four weeks) and combinations of IDEC-114 with Rituxan, the current standard treatment for relapsed or refractory, follicular lymphoma.

“The data indicate that IDEC-114 is both well-tolerated at the dose levels administered and clinically active, especially at the higher dose levels,” said Myron Czuczman, M.D., principal investigator of the clinical study. “Interestingly, we observed several complete responses to IDEC-114 which were achieved months following treatment.”

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 monoclonal antibody product (Rituxan(R)) and the first radioimmunotherapy product (Zevalin(R)) approved in the United States for the treatment of cancer. IDEC is a San Diego based, integrated biopharmaceutical company with multiple products in clinical stage development and strategic alliances in 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.

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.

CONTACT: IDEC Pharmaceuticals Corporation