Capital Restructuring Reduces Fully Diluted Share Count by More Than 80%

SAN DIEGO, CA–(Marketwired – Sep 30, 2013) – La Jolla Pharmaceutical Company (OTCBB: LJPC) (the “Company” or “La Jolla”) (http://www.ljpc.com/), a leader in the development of therapeutics targeting significant unmet life-threatening diseases, today announced that it has closed the previously announced private placement of approximately 96 million shares of common stock at a price of $0.07 per share and 3,250 share of Series F Preferred Stock priced at $1,000 per share. The transaction yielded gross proceeds of approximately $10 million. As a result of the restructuring the Company now would have a maximum of 871 million shares of common stock on a fully diluted basis.

The proceeds of this offering will be used to complete the Company’s ongoing Phase 2 clinical study of patients with Chronic Kidney Disease and will also fund a planned Phase 1 proof-of-concept clinical study of LJPC-501 in hepatorenal syndrome.

This press release will not constitute an offer to sell or the solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such jurisdiction.

The securities sold in the private placement have not been registered under the Securities Act of 1933, as amended, or state securities laws and may not be offered or sold in the United States absent registration with the Securities and Exchange Commission (SEC) or an applicable exemption from such registration requirements.

About La Jolla Pharmaceutical Company

La Jolla Pharmaceutical Company is a biopharmaceutical company focused on the discovery, development and commercialization of innovative therapeutics for chronic organ failure and cancer. GCS-100, the Company’s lead product candidate, is a first-in-class inhibitor of galectin-3, a novel molecular target implicated in chronic organ failure and cancer. LJPC-501, the Company’s second product candidate, is a natural peptide for the treatment of hepatorenal syndrome. For more information on the Company please visit http://www.ljpc.com.

Forward Looking Statement Safe Harbor

This document contains forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. These statements relate to future events or our future results of operations. These statements are only predictions and involve known and unknown risks, uncertainties and other factors, which may cause actual results to be materially different from these forward-looking statements. The Company cautions readers not to place undue reliance on any such forward-looking statements, which speak only as of the date they were made. Certain of these risks, uncertainties, and other factors are described in greater detail in the Company’s filings with the U.S. Securities and Exchange Commission (“SEC”), all of which are available free of charge on the SEC’s web site http://www.sec.gov. These risks include, but are not limited to, risks relating to the development of GCS-100 and LJPC-501, the success and timing of future preclinical and clinical studies of these compounds, the use of proceeds from financings and potential indications for which GCS-100 and LJPC-501 may be developed. Subsequent written and oral forward-looking statements attributable to the Company or to persons acting on its behalf are expressly qualified in their entirety by the cautionary statements set forth in the Company’s reports filed with the SEC. The Company expressly disclaims any intent to update any forward-looking statements.