mrc

London, UK, and Pittsboro, North Carolina, USA, July 14, 2008 – MRC Technology (MRCT) (London,
UK) and Biolex Therapeutics, Inc. (Pittsboro, North Carolina, USA) announced today that MRCT had
successfully completed the humanization of a novel antibody targeting CD20, indicated in Non-
Hodgkin’s lymphoma and rheumatoid arthritis. Biolex is applying its proprietary glycosylation
optimization technology to the antibody, BLX-301, to enhance efficacy and potency of the product
candidate and potentially reduce certain side effects.

“We are delighted to have been able to provide Biolex with a humanized version of its CD20
antibody. The project was completed on schedule and the resulting antibody retained all desired
binding characteristics,” said Dr. Tarran Jones, Director of MRCT’s Therapeutic Antibody Group
(TAG). “This collaborative project marks the 35th monoclonal antibody that we have successfully
humanized using our proprietary humanization technology over the past 20 years.”
Biolex will retain all development and commercialization rights to the humanized antibody, and
MRCT will receive regulatory milestone payments and royalties upon its successful development.
Additional financial terms were not disclosed.

“We have been pleased to collaborate with MRCT on this project and appreciate the successful
track record they have demonstrated in the area of antibody humanization,” said Mr. Jan Turek,
President & CEO of Biolex Therapeutics. “Applying the glycosylation optimization capabilities of our
LEX SystemSM to a humanized antibody provides the potential for a next-generation product that
offers a therapeutic advantage while also addressing the relatively low potency and problematic
side-effect burden of the current standard of care.”

Notes to Editors

Antibody Humanization
Antibody humanization, also known as CDR-grafting (CDR is a synonym for complementarity
determining region) was first invented at the MRC Laboratory of Molecular Biology in the UK by Dr.
Sir Greg Winter and patented by the MRC in the late 1980's. CDR-grafting involves the genetic
transfer of mouse CDRs (which are responsible for antigen binding) into human frameworks of a
variable region. A variable region is one domain of an immunoglobulin chain, a whole antibody
itself comprising of one light and one heavy immunoglobulin chain. The key to success in antibody
Biolex Therapeutics 2 MRC Technology
humanization is the careful analysis of the mouse antibody to identify key framework residues
important for the preservation of antibody function in the humanized antibody.

About Medical Research Council Technology (MRCT)
MRCT is the exclusive commercialization catalyst for the UK Medical Research Council (MRC),
working to translate cutting edge scientific discoveries into commercial products. MRCT bridges the
gap between innovative basic science and making medicine. By providing both chemical tools and
therapeutic antibody candidates, we give pharmaceutical and biotechnology companies new
starting points for drug discovery and development, based on MRC advances in science.

About Therapeutic Antibody Group (TAG)
MRCT’s TAG scientists have a proven track record of success in antibody humanization which
extends over 20 years and has produced 11 clinical candidates and two regulatory approved
humanized antibodies: Elan/Biogen Idec’s Tysabri® and Chugai/Roche’s Actemra®. TAG
collaborates with MRC scientists to translate innovative antibody-based drug targets into potent
and selective therapeutic antibody candidates which can then be partnered with industry. In
addition, MRCT provides the pharmaceutical and biotechnology industry access to the world-class
antibody humanization expertise of TAG.

About Biolex Therapeutics
Biolex is a clinical-stage biopharmaceutical company that uses its patented LEX SystemSM 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®, is in Phase 2 clinical trials and is the only controlled-release
interferon alfa in 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.

MRCT Contact Information
Dr Tarran Jones, Director of TAG (tarran.jones@tech.mrc.ac.uk)
MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London NW7 1AD, UK.
Website: www.mrctechnology.org Phone: +44 (0)20 8906 7100 Fax: +44 (0)20 8906 7200

Biolex Contact Information
Media: Michelle Linn, Linnden Communications, +1-774-362-3087, linnmich@comcast.net
Investors: Dale Sander, Chief Financial Officer, +1-858-663-6993, dsander@biolex.com