La Jolla Pharmaceutical Company Release: Mechanism of Action for GS-100 in Lymphoma Published in Blood

SAN DIEGO, CA--(Marketwire - October 16, 2012) - La Jolla Pharmaceutical Company (OTCQB: LJPC) (the “Company” and “La Jolla”) announced today that researchers at UCLA’s Jonsson Comprehensive Cancer Center have discovered the mechanism by which the Company’s lead drug candidate, GS-100, makes lymphoma cells more responsive to chemotherapy. The findings were published in the online edition of Blood, October 12, 2012, with printed publication to follow.

The study “Galectin-3 binds to CD45 on diffuse large B cell lymphoma cells to regulate susceptibility to cell death” was conducted by Dr. Linda G. Baum and her colleagues at UCLA’s Jonsson Comprehensive Cancer Center. It focused on diffuse large B cell lymphoma (DLBCL), the most commonly diagnosed form of non-Hodgkin’s lymphoma (NHL). The researchers were interested in finding out the mechanism by which these tumor cells can evade the action of chemotherapy agents. They found that the protein galectin-3 binds to an enzyme called CD45 on the surface of lymphoma cells and it is this protein-enzyme combination that regulates the susceptibility of the cells to chemotherapy drugs. They showed that treating the lymphoma cells with GS-100 can remove the protective effect of galectin-3. The cells can then be effectively killed by chemotherapy agents such as dexamethasone, rituximab and etoposide.

“These findings have important implications for the use of GS-100 in treating cancer,” said Dr. George Tidmarsh, President and Chief Executive Officer of La Jolla. “Dr. Baum and her colleagues have proposed a broad mechanism of tumor resistance in DLBCL and have shown that GS-100 has excellent potential as a chemotherapy sensitizing agent. This study confirms prior work which has shown that GS-100 increases the activity of known anti-cancer agents.”

GCS-100 is a complex polysaccharide that has the ability to bind to and block the effects of galectin-3. The unique ability of GCS-100, to bind and sequester galectin-3 makes it an ideal candidate to prevent and treat diseases in which galectin-3 plays an important role, such as chronic organ failure and cancer.

About La Jolla Pharmaceutical Company
La Jolla Pharmaceutical Company is a biopharmaceutical company dedicated to the development of treatments that significantly improve outcomes in patients with life-threatening diseases. 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.

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 from time to time with the U.S. Securities and Exchange Commission (SEC), all of which are available free of charge on the SEC’s web site at http://www.sec.gov. These risks include, but are not limited to, risks relating to the development of GCS-100, the success and timing of future preclinical and clinical studies of this compound, and potential indications for which GCS-100 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.