ChemoCentryx and Forest Laboratories to Collaborate on the Development and Commercialization of Novel Oral Rheumatoid Arthritis and Multiple Sclerosis Therapeutics.

Business Editors/Health/Medical Writers

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SAN CARLOS, Calif. & NEW YORK--(BUSINESS WIRE)--March 15, 2004

ChemoCentryx, Inc., a privately held focused pharmaceutical company, and Forest Laboratories, Inc. (NYSE:FRX) announced today that the two companies have entered into a collaboration agreement to develop and commercialize novel small molecule therapeutics for autoimmune and inflammatory diseases such as rheumatoid arthritis and multiple sclerosis. The collaboration focuses on CCR1, a specific chemokine receptor involved in inflammation. The most advanced compound may be ready to enter Phase I clinical studies within the next 12 months.

Under the terms of the agreement, Forest will license on a worldwide basis small molecule development candidates discovered by ChemoCentryx, and will take the lead in the clinical development and commercialization of the drugs. ChemoCentryx will receive an upfront payment from Forest in the form of a cash licensing fee and the purchase of ChemoCentryx preferred stock. Forest will provide funding for a joint research program for up to three years. Forest will have exclusive rights to all CCR1 antagonists developed during that period and will take the lead in clinical development. Forest will pay ChemoCentryx upfront, research and milestone payments as well as significant royalties for products arising from the collaboration. In addition, ChemoCentryx has the option to co-fund certain U.S. clinical development activities, which would increase its royalties on U.S. sales. ChemoCentryx retains the option to co-promote products to certain physician specialists in the U.S.

"We are delighted to enter into this collaboration with Forest, a committed partner with proven capabilities in the development and marketing of innovative products across diverse therapeutic categories," stated Thomas Schall, Ph.D., Chief Executive Officer of ChemoCentryx. "This collaboration will increase the rapid clinical advancement of the ChemoCentryx pipeline, providing synergies with our internal efforts and proprietary programs, as well as solidifying our progression as a development-stage company. The chemokine system is proving to be a rich target for highly potent and highly specific small molecule therapeutics."

"We have been seeking ways to expand our pipeline potential by reaching further back into earlier stage compounds, while, at the same time, continuing our active pursuit of later stage compounds," commented Howard Solomon, Forest's Chairman and Chief Executive Officer. "Within the last several years we identified malfunction of the inflammation system and the auto-immune response as the progenitors of many disease entities, and embarked on an active search for targets, researchers, and compounds that had the greatest potential to modulate those diseases. That search led us to ChemoCentryx and its chemokine program. Although this program involves long term commitments and associated risks, the areas involved, the preclinical data already available, the brilliant work already done by our collaborator, and the availability of worldwide rights, which may at various stages of the development program enable us to share the risk and to facilitate other licensing opportunities for foreign rights, all make this a very exciting collaboration for us."

New Medicines Based on the Chemokine System

The chemokine system regulates the trafficking of immune cells around the body. In a healthy individual, chemokines activate the immune system to fight disease and maintain immune system equilibrium. Disequilibrium of the chemokine network, however, is at the core of autoimmune and inflammatory disorders, such as rheumatoid arthritis, multiple sclerosis and other diseases. Chemokines are also critical to the establishment of infection by many pathogens and to the establishment and progression of some cancers. ChemoCentryx is discovering small molecule compounds with the potential to block specific chemokine receptors in order to reduce or eliminate the excessive and harmful immune response in many inflammatory and autoimmune diseases. New oral, chemokine-based therapeutics have the potential to treat diseases not adequately treated presently or treatable primarily with an injectable drug regimen. Chemokine antagonists may provide high target selectivity and disease specificity and improved patient compliance. Among these, CCR1 antagonists provide a new approach to block the chronic inflammation and autoimmune response associated with rheumatoid arthritis, multiple sclerosis and other relevant diseases without a general immuno-suppressive effect.

About ChemoCentryx

ChemoCentryx, Inc. discovers, develops and commercializes novel small molecule medicines for autoimmune diseases, inflammatory disorders, cancer and infectious disease. ChemoCentryx has advanced Traficet-EN(TM), the company's orally active drug for inflammatory bowel disease, into Phase I clinical trials. Other programs include emerging drug candidates for cancer and cardiopulmonary inflammation. ChemoCentryx's first lead compound, an oral treatment for psoriasis, entered into Phase II clinical study initiated by the company's partner, Tularik. In addition, an orally active development candidate for rheumatoid arthritis and multiple sclerosis is the subject of the company's collaboration with Forest Laboratories. Leveraging its leadership in chemokine-based drug discovery, ChemoCentryx focuses on new classes of orally active small molecules to selectively inhibit activity of the chemokine system, the "master regulator" of immune response. Based in San Carlos, California, ChemoCentryx is privately held. For more information on the company, visit www.chemocentryx.com.

Any statements in this press release about ChemoCentryx's expectations, beliefs, plans, objectives, assumptions or future events or performance are not historical facts and are forward-looking statements. These statements are often, but not always, made through the use of words or phrases such as "believe," "will," "expect," "anticipate," "estimate," "intend," "plan," and "would." Forward-looking statements are not guarantees of performance. They involve known and unknown risks, uncertainties and assumptions that may cause actual results, levels of activity, performance or achievements to differ materially from any results, levels of activity, performance or achievements expressed or implied by any forward-looking statement. Some of the risks, uncertainties and assumptions that could cause actual results to differ materially from estimates or projections contained in the forward-looking statements include but are not limited to (i) the timing, success and cost of preclinical research and clinical studies, (ii) the timing, acceptability and review periods for regulatory filings, (iii) the availability of corporate partners, (iv) uncertainties relating to patent protection and intellectual property rights of third parties, (v) the impact of competitive products and technological changes, (vi) the availability of capital and the cost of capital, (vii) other vagaries in the biotechnology industry and (viii) other risks. ChemoCentryx undertakes no obligation to update or revise any forward-looking statements.

About Forest Laboratories and Its Products

Forest Laboratories' growing line of products includes: Lexapro(R) an SSRI antidepressant indicated for the initial and maintenance treatment of major depressive disorder and Generalized Anxiety Disorder; Celexa(R), an antidepressant; Namenda(TM), an N-methyl D-aspartate (NMDA) receptor antagonist indicated for the treatment of moderate to severe Alzheimer's disease; Tiazac(R), a once-daily diltiazem, indicated for the treatment of angina and hypertension; Benicar(R)*, an angiotensin receptor blocker indicated for the treatment of hypertension; Benicar HCT, an angiotensin receptor blocker and diuretic combination product indicated for the second- line treatment of hypertension; and Aerobid(R), an inhaled steroid indicated for the treatment of asthma.

*Benicar(R) is a registered trademark of Sankyo Pharma, Inc.

Except for historical information contained herein, this release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are subject to risks and uncertainties that affect our business, including risk factors listed from time to time in the Company's SEC reports, including the Company's Annual Report on Form 10-K for the fiscal year ended March 31, 2003, and Quarterly Reports on Form 10-Q for the periods ending June 30, 2003, September 30, 2003, and December 31, 2003. Actual results may differ materially from those projected.