Abundance of New Studies Heightens Critical Need for Clinical Trial Participation

SAN DIEGO, June 11, 2002 -- La Jolla Pharmaceutical Company (Nasdaq: LJPC) today announced that industry and leaders of the national lupus, arthritis and psoriasis patient advocacy organizations will discuss clinical trial enrollment at the Biotechnology Industry Organization (BIO) 2002 International Conference and Exhibition in Toronto, Canada this morning at 8:30 a.m.

"The good news is that the biotechnology industry is developing an unprecedented wave of drug candidates, offering hope of potential new therapies. Unfortunately, a lack of patients to participate in this growing number of clinical trials will pose a significant bottleneck to the availability of these promising drugs," said Steven B. Engle, La Jolla Pharmaceutical Company's Chairman and CEO. "By working together, patient advocacy groups, biotechnology companies and others can educate the public on the critical importance of clinical trial participation."

"Voluntary health associations bring together patients and companies seeking to develop new therapies for a range of diseases," said Gail M. Zimmerman, President and CEO of the National Psoriasis Foundation. "Through awareness, education and ensuring access to clinical trials, we can help in the race to provide new treatments to patients who may otherwise be faced with limited options for care."

The panel will include Ms. Zimmerman; Sandra Claire Raymond, President and CEO of the Lupus Foundation of America; and Tino J. Mantella, President and CEO of the Arthritis Foundation. Mr. Engle will chair the panel. The panel discussion is entitled "Changing the Future of Clinical Trial Recruitment by Building Ties with Patient Advocates."

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. Patients interested in the Phase III lupus trial may call 1-800-30-LUPUS for information.

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.