Exhibit 99.1

                LA JOLLA PHARMACEUTICAL ANNOUNCES PUBLICATION OF
               REVIEW ARTICLES REGARDING ITS TWO DRUG CANDIDATES

SAN DIEGO, JUNE 24, 2004 - La Jolla Pharmaceutical Company (Nasdaq: LJPC) today
announced that two articles were published in the journal Lupus (Vol. 13, Issue
5) reviewing the Company's drug candidates Riquent(R) (abetimus sodium, formerly
LJP 394) for the treatment of lupus renal disease and LJP 1082 for the treatment
of antibody-mediated thrombosis. The articles summarize the large body of
previously announced data collected from several clinical studies evaluating
Riquent as well as the Company's tolerance technology.

Two leading lupus clinicians, Daniel Wallace, M.D., Clinical Professor of
Medicine, Department of Medicine, Division of Rheumatology, Cedars-Sinai/UCLA
School of Medicine, and James Tumlin, M.D., Associate Professor of Medicine,
Renal Division, Emory University Medical School, published a paper (page
323-327) entitled: "LJP 394 (Abetimus Sodium, Riquent) in the Management of
Systemic Lupus Erythematosus." The paper summarizes the clinical development of
Riquent and focuses on results from the Phase 2/3 and Phase 3 clinical trials,
in which Drs. Wallace and Tumlin were clinical investigators. The data from
these trials support the Company's New Drug Application for Riquent currently
under FDA review.

In the same issue, Joan Merrill, M.D., Clinical Pharmacology Research Program,
Oklahoma Medical Research Foundation, published an article (page 335-338)
entitled: "LJP 1082: A Toleragen for Hughes Syndrome." The article discusses B
cell tolerance and summarizes the clinical rationale for LJP 1082, the Company's
drug candidate specifically designed to treat the underlying cause of
antibody-mediated thrombosis. Dr. Merrill is a leading clinical researcher in
antibody-mediated thrombosis and was a clinical investigator in a Phase 1/2
clinical trial of LJP 1082, which was completed in October 2002.

Lupus, systemic lupus erythematosus or SLE, is a chronic, potentially
life-threatening autoimmune disease. About 90% of lupus patients are female, and
many develop the disease during their childbearing years. Approximately 50% of
lupus patients have renal disease, which can lead to irreversible kidney damage,
kidney failure and the need for dialysis. Latinos, African Americans and Asians
face an increased risk of serious renal disease associated with lupus. The
current standard of care for lupus renal disease often involves treatment with
high doses of corticosteroids and immunosuppressive drugs that can cause severe
side effects including diabetes, hypertension and sterility, and may leave
patients vulnerable to opportunistic infections.

Antibody-mediated thrombosis is an autoimmune disease characterized by the
formation of blood clots that can lead to stroke, heart attack, deep vein
thrombosis and recurrent miscarriage. This disease, also known as
Antiphospholipid Syndrome, affects an estimated one to two million people in the
United States and Europe. Patients often experience their first thrombotic event
in their 20s or 30s, and studies indicate they have twice the probability of a
recurrence. Current treatments include anticoagulants, the

long-term use of which can lead to side effects including life-threatening
bleeding events.

La Jolla Pharmaceutical Company is a biotechnology company developing
therapeutics for antibody-mediated autoimmune diseases and inflammation
afflicting several million people in the United States and Europe. The Company
is developing Riquent(R) for the treatment of lupus kidney disease, a leading
cause of sickness and death in patients with lupus. The Company is also
developing LJP 1082 for the treatment of antibody-mediated thrombosis, a
condition in which patients suffer from recurrent stroke, deep-vein thrombosis,
miscarriage and other thrombotic events, and is in the early stage of developing
small molecules to treat various other autoimmune and inflammatory conditions.
The Company's common stock is traded on The Nasdaq Stock Market under the symbol
LJPC. For more information about the Company, visit its Web site:
http://www.ljpc.com.

This press release contains forward-looking statements that involve significant
risks and uncertainties, and a number of factors, both foreseen and unforeseen,
could cause actual results to differ materially from our current expectations.
Forward-looking statements include those that express a plan, belief,
expectation, estimation, anticipation, intent, contingency, future development
or similar expression. Although our New Drug Application ("NDA") for Riquent(R)
has been accepted by the United States Food and Drug Administration (the "FDA")
for review, there is no guarantee that the FDA will approve Riquent in a timely
manner, or at all. Our analyses of clinical results of Riquent, previously known
as 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 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. The analysis of
the data from our Phase 3 trial of Riquent showed that the trial did not reach
statistical significance with respect to its primary endpoint, time to renal
flare, or to the secondary endpoint, time to treatment with high-dose
corticosteroids or cyclophosphamide. Although our NDA for Riquent has been
accepted for review by the FDA, the results from our clinical trials of Riquent
may not ultimately be sufficient to obtain regulatory clearance to market
Riquent either in the United States or Europe, and we may be required to conduct
additional clinical studies to demonstrate the safety and efficacy of Riquent in
order to obtain marketing approval. There is no guarantee, however, that we will
have the necessary resources to complete any additional trial, that we will
elect to conduct an additional trial, or that any additional trial will
sufficiently demonstrate the safety and efficacy of Riquent. Our blood test to
measure the binding affinity for Riquent is experimental, has not been validated
by independent laboratories and will likely be reviewed as part of the Riquent
approval process. 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. In any event, regulatory authorities may
require additional clinical trials, or may not approve our drugs. Our ability to
develop and sell our products in the future may be adversely affected by the
intellectual property rights of third parties. Additional

risk factors include the uncertainty and timing of: obtaining required
regulatory approvals, including delays associated with any approvals that we may
obtain; the clear need for additional financing; our ability to pass FDA
pre-approval inspections of our manufacturing facilities and processes; the
increase in capacity of our manufacturing capabilities for possible
commercialization; successfully marketing and selling our products; our lack of
manufacturing, marketing and sales experience; our ability to make use of the
orphan drug designation for Riquent; generating future revenue from product
sales or other sources such as collaborative relationships; future
profitability; and our dependence on patents and other proprietary rights.
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 Annual Report on Form 10-K for the year ended
December 31, 2003, and in other reports and registration statements that we file
with the Securities and Exchange Commission from time to time.

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