LA JOLLA PHARMACEUTICAL ANNOUNCES ADDITIONS TO SENIOR MANAGEMENT

SAN DIEGO, October 23, 2002 -- La Jolla Pharmaceutical Company (Nasdaq: LJPC) announced today that it has appointed David Duncan, Jr. to the position of Chief Financial Officer and Karen Church, R.A.C. to the position of Vice President of Regulatory Affairs. Additionally, the Company announced that it has promoted Matthew D. Linnik, Ph.D. from Executive Vice President of Research to Chief Scientific Officer and Executive Vice President of Research and William J. Welch from Vice President of Marketing to Vice President of Sales and Marketing.

"Dave is a seasoned financial executive with more than 29 years experience in the healthcare and information systems industries, including a strong background in international operations and product manufacturing. Karen has been involved in the submission of numerous New Drug Applications during her 30 years in regulatory affairs. We believe that they are a timely addition to our management team, and that their experience and knowledge will greatly benefit the Company," said Steven B. Engle, Chairman and CEO. "Additionally, we commend Matt and Bill on their accomplishments and congratulate them on their promotions."

Mr. Duncan has spent 14 years as Chief Financial Officer at Medinox, Inc., Tanox, Inc., Neuromedical Systems, Inc., and Telios Pharmaceuticals, Inc. Prior to that he served as Controller for five years at Hybritech, Inc., one of the first biotechnology companies in San Diego. He spent 10 years in various financial positions at Burroughs Corporation (now Unisys Corporation), a manufacturer of information systems. Mr. Duncan has been responsible for financial planning and reporting, investor relations, banking and cash management functions, and strategic planning. He helped to complete five public offerings, including a $244 million initial public offering for Tanox. He received his MBA and BS in Finance from Indiana University.

With 30 years of experience, Ms. Church helped file more than 10 New Drug Applications with the U.S. Food and Drug Administration, three European Marketing Authorization Applications and more than 100 Investigational New Drug applications. She has held regulatory positions with Ancile Pharmaceuticals, Inc., Gensia, Inc. (now Sicor, Inc.), Neurocrine Biosciences, Inc., InSite Vision, Inc., Hoffman La Roche, Abbott Laboratories and Astra Pharmaceutical Products (now AstraZeneca, PLC). She has worked with the Center for Drug Evaluation and Research, including the Cardio-Renal Division, the Center for Biologics Evaluation and Research and the European Agency for the Evaluation of Medicinal Products. She has worked with product candidates in therapeutic areas such as cardiology, nephrology, immunology, oncology, neurology, metabolic endocrinology, anti-inflammatory, anti-infective, pulmonary, urology, and dermatology. She is a former President of the Drug Information Association, a professional organization for drug development in the pharmaceutical and biotechnology industries with more than 27,000 members worldwide. Ms. Church also serves as an adjunct professor in the Regulatory Affairs graduate program at San Diego State University. She received her BS from the University of Wyoming and her RAC from the Regulatory Affairs Professionals Society.

La Jolla Pharmaceutical Company is a biotechnology company leading the development of therapeutics for antibody-mediated autoimmune diseases afflicting several million people in the United States and Europe. The Company is conducting a Phase III trial of LJP 394 in patients with lupus kidney disease, a leading cause of sickness and death in these patients. The Company is also conducting a Phase I/II trial of LJP 1082 for the treatment of antibody-mediated thrombosis, a condition in which patients suffer from recurrent stroke, deep-vein thrombosis and other thrombotic events. The Company's common stock is traded on The Nasdaq Stock Market under the symbol LJPC. For more information about the Company, visit our Web site: http://www.ljpc.com.

Except for historical statements, this press release contains forward-looking statements involving significant risks and uncertainties, and a number of factors, both foreseen and unforeseen, could cause actual results to differ materially from our current expectations. Our analyses of clinical results of LJP 394, our drug candidate for the treatment of systemic lupus erythematosus ("lupus"), and LJP 1082, our drug candidate for the treatment of antibody-mediated thrombosis ("thrombosis"), are ongoing and future analyses could result in a finding that these drug candidates are not effective in large patient populations, do not provide a meaningful clinical benefit or may reveal a potential safety issue requiring us to develop new candidates. Our blood test to measure the binding affinity for LJP 394 is experimental, has not been validated by independent laboratories, may require regulatory approval and may be necessary for the approval and the commercialization of LJP 394. Our other potential drug candidates are at earlier stages of development and involve comparable risks. Analysis of our clinical trials could have negative or inconclusive results. Any positive results observed to date may not be indicative of future results. Even if results are promising, the U.S. Food and Drug Administration ("FDA") may require additional clinical trials. The Company's ability to develop and sell its products in the future may be affected by the intellectual property rights of third parties. Additional risk factors include the uncertainty of: obtaining required regulatory approvals; successfully marketing products; receiving future revenue from product sales or other sources such as collaborative relationships; future profitability; the need for
additional financing; our dependence on patents and other proprietary rights; FDA approval of our manufacturing facilities; the increase in capacity of our manufacturing capabilities for possible commercialization; and our lack of marketing experience. Readers are cautioned to not place undue reliance upon forward-looking statements, which speak only as of the date hereof, and we undertake no obligation to update forward-looking statements to reflect events or circumstances occurring after the date hereof. Interested parties are urged to review the risks described in our other reports and registration statements filed with the Securities and Exchange Commission from time to time, including the report on Form 10-K for the year ended December 31, 2001.