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SAN DIEGO, Dec. 23 /PRNewswire-FirstCall/ -- Neurocrine Biosciences, Inc. (Nasdaq: NBIX) today announced results from its second trial with IL-4 Fusion Toxin (NBI-3001) for the treatment of glioblastoma multiforme (GBM) malignant brain tumors. An earlier study had shown NBI-3001 to be safe with demonstrated anti-tumor effects in the majority of patients receiving NBI-3001. The recently completed study was designed to explore an improved delivery regimen and to determine a safe and optimal dose for Phase III trials. The study enrolled 32 patients with recurrent GBM using an open label design. NBI-3001 was infused intratumorally at high, medium, and low dose levels over 5 days, followed 3 weeks later by tumor resection. At the low dose of 90 mcg, the drug was well tolerated and was associated with a low incidence (10%) of drug-related serious adverse events within the first 2 weeks of infusion. Median survival for this dose group was greater than six months with the majority of patients still alive at the time follow up data were last analyzed. Although direct comparisons between glioblastoma studies must be guarded, the clinical outcomes in this study compare favorably with those reported using currently available therapies for patients with similar stage disease. Evaluable MRI scans showed approximately 25% of the patients reached stable or partial regression of disease. These results indicate a safe and well-tolerated dose has been determined and that the compound is now ready to enter advanced efficacy trials using survival as the valid endpoint.

Concurrently, Neurocrine has been conducting a Phase I safety dose escalation study with NBI-3001 in patients with peripheral solid tumors that over express IL-4 receptors such as kidney and lung carcinoma. The treatment regimen calls for short intravenous infusions for five days each month for up to six months in an out-patient setting. While the study is still ongoing, preliminary results indicate this study has successfully met the primary objectives of defining a dose-limiting toxicity (reversible liver enzyme elevations) and the maximum tolerated dose. No other drug-related effects were identified although neutralizing antibodies were detected after repeated cycles in the majority of patients. The data on the presence of neutralizing antibodies are consistent with those seen for other similar compounds. Two patients with kidney carcinoma showed stable disease at this maximum tolerated dose. These data will allow more rigorous Phase I and Phase II trials to proceed in order to confirm broader antitumor efficacy prior to initiating later stage clinical trials in peripheral solid tumors.

"We are pleased that we have successfully met the prospective endpoints in both these studies with IL-4 Fusion Toxin," said Gary Lyons, President & CEO of Neurocrine. "Given our recent success with indiplon and our new focus on building a psychiatric portfolio and plans to evolve into a sales and marketing organization, we have decided this product no longer meets our strategic objective. We will pursue out licensing opportunities in 2003 to put this asset in the hands of an oncology-focused company. In the first quarter we will complete a dossier on this product and will begin to look for a suitable licensee."

"With this trial, the company has now studied NBI-3001 in 72 patients with glioblastoma. The results have shown that the drug can be delivered safely prior to tumor resection. Several patients at the safest clinical dose have now survived beyond eight months. We believe this compound has potential for further clinical evaluation in treating GBM," said Henry Pan, M.D., Ph.D., Executive Vice President and Chief Medical Officer for Neurocrine Biosciences.

Preclinical data suggest that when infused directly into a glioblastoma, IL-4 Fusion Toxin kills tumor cells but not the healthy brain cells. IL-4 Fusion Toxin is a protein in which a blood cell derived growth factor (IL-4) has been joined with a Pseudomonas exotoxin, a potent toxin that can destroy cancer cells. IL-4 has very high affinity for-IL-4 receptors, which are highly localized on malignant brain tumors, but not on normal brain cells. IL-4 binds tightly to the IL-4 receptors on the surface of the glioblastoma cells and delivers the exotoxin directly into the cell, resulting in cell death. IL-4 Fusion Toxin is administered via a special catheter that permits delivery directly into the brain tumor.

Neurocrine Biosciences, Inc. is a product-based biopharmaceutical company focused on neurological and endocrine diseases and disorders. Our product candidates address some of the largest pharmaceutical markets in the world including insomnia, anxiety, depression, malignant brain tumors, diabetes, multiple sclerosis, irritable bowel syndrome, eating disorders, pain, stroke, and certain female health disorders. Neurocrine Biosciences, Inc. news releases are available through the Company's website via the Internet at http://www.neurocrine.com .

In addition to historical facts, this press release contains forward-looking statements that involve a number of risks and uncertainties. Among the factors that could cause actual results to differ materially from those indicated in the forward looking statements are risks and uncertainties associated with Neurocrine's NBI-3001 development program and business and finances including, but not limited to, risks associated with licensing of NBI-3001 including identification of an appropriate oncology-focused licensee and negotiation of acceptable terms, further, if such a licensee is obtained, risk that NBI-3001 will not successfully proceed through clinical trials or that clinical trials will not show that it is safe and effective in treating humans; determinations by regulatory and governmental authorities; availability of corporate partners for NBI-3001; uncertainties relating to patent protection and intellectual property rights of third parties; impact of competitive products and technological changes; availability of capital and cost of capital; and other material risks. A more complete description of these risks can be found in the Company's Form 10K for December 31, 2001 and the quarterly report filed on Form 10-Q for the quarter ended September 30, 2002. Neurocrine undertakes no obligation to update the statements contained in this press release after the date hereof.

SOURCE Neurocrine Biosciences, Inc.