Preclinical Results Demonstrate Potential for Improved Efficacy and Potency and Reduced Side Effects Compared to Rituxan(R)

PITTSBORO, NC, USA | December 10, 2007 | Biolex Therapeutics today announced that preclinical results of an anti-CD20 antibody optimized in its proprietary LEX System(SM) were presented yesterday at the 49th Annual Meeting of the American Society of Hematology (ASH) in Atlanta, Georgia. The results highlight the ability of the LEX System to produce an anti-CD20 antibody with an optimized glycosylation structure with enhanced antibody dependent cellular cytotoxicity (ADCC), more potent B-cell depletion, and potentially lower side effects compared to Rituxan® (rituximab), the current standard of care for the treatment of non-Hodgkin’s B-cell lymphoma. Biolex is developing BLX-301, a humanized anti-CD20 candidate incorporating the optimized glycosylation benefits of the LEX System.

"We are pleased with these results as they demonstrate the potential for a next-generation product that provides a therapeutic advantage while also addressing the relatively low potency and side-effect burden of the current standard of care," said Mr. Jan Turek, Biolex President and Chief Executive Officer. "Monoclonal antibodies are the fastest growing class of therapeutics in the pharmaceutical sector, and glycosylation can play a significant role in their therapeutic function. In addition to supporting the potential benefits of our BLX-301 candidate, these results also highlight the capability of the LEX System to improve the therapeutic benefits of a broad range of antibodies that can be enhanced through optimization of their glycosylation structures."

Anti-CD20 Results Presented at ASH Conference

The optimized rituximab included in the studies reported at the ASH conference was developed and produced in Biolex’s LEX System, a next-generation platform for the production of biologic products. As reported in December 2006 in Nature Biotechnology, the LEX System has the ability to produce monoclonal antibodies with a fully human glycosylation structure without fucose. Research suggests that antibodies with a glycosylation structure that lacks fucose may improve therapeutic efficacy by enhancing ADCC, particularly in the treatment of cancer, autoimmune diseases, infectious diseases and inflammatory diseases. The LEX System can also produce monoclonal antibodies that have a fully G0 glycosylation structure, meaning they lack galactose. Research suggests that a G0 glycosylation structure provides the additional benefit of potentially reducing complement dependent cytotoxicity (CDC), thereby reducing side effects and the long infusion times associated with treatment with Rituxan and certain other antibodies.

As reported at the ASH conference, researchers evaluated an optimized version of rituximab produced in the LEX System to further support the potential benefits of developing an anti-CD20 antibody incorporating the LEX System optimization. Optimized rituximab produced in the LEX System demonstrated higher ADCC efficacy and 20 to 200 times higher potency than the current Rituxan. Furthermore, preliminary results suggest optimized rituximab was also more effective than Rituxan at causing B-cell depletion in whole blood. Lastly, the optimized rituximab produced in the LEX System with its G0 glycosylation structure had ten-fold lower CDC than Rituxan. Complement dependent cytotoxicity has been reported to be a key contributor to the serious side effects and long infusion times associated with Rituxan treatment.

Rituxan is approved for treatment of non-Hodgkin’s B-cell lymphoma and rheumatoid arthritis. It is also being studied for use in other autoimmune diseases such as immune thrombocytopenic purpura, systemic lupus erythematosus, and multiple scelerosis. Biolex is developing BLX-301, a humanized anti-CD20 candidate incorporating the optimized glycosylation benefits of the LEX System, and currently expects that the first indication targeted for development will be non-Hodgkin’s B-cell lymphoma.

About Biolex Therapeutics

Biolex is a clinical-stage biopharmaceutical company that uses its patented LEX System(SM) to develop hard-to-make therapeutic proteins and to optimize monoclonal antibodies. The LEX System is a novel technology that genetically transforms the aquatic plant Lemna to enable the production of biologic product candidates. The company’s product candidates are designed to provide superior efficacy/tolerability profiles and to address large, proven pharmaceutical markets. Biolex’s lead product candidate, Locteron®, under joint development with OctoPlus N.V., is in Phase 2 clinical trials and is the only controlled-release interferon alfa known to be currently in active clinical development for the treatment of chronic hepatitis C. Biolex has also developed two other product candidates that capitalize on the benefits of the LEX System, which it is advancing toward clinical trials: BLX-155, a direct-acting thrombolytic designed to dissolve blood clots in patients; and BLX-301, an anti-CD20 antibody it is optimizing for the treatment of non-Hodgkin’s B-cell lymphoma and other diseases.

SOURCE: Biolex Therapeutics