Protalix Reports Preclinical Data on Anti-TNF Follow-on Biologic Arthritis Drug

Protalix Reports Preclinical Data on Anti-TNF Follow-on Biologic Arthritis Drug

CARMIEL, Israel, September 22, 2009 (Business Wire) Protalix Biotherapeutics, Inc. (NYSE-Amex:

PLX), reported today preclinical data on pr-antiTNF, a biosimilar version of etanercept (Enbrel ).

Produced using the Company s proprietary ProCellEx technology, pr-antiTNF is a plant cell

expressed recombinant fusion protein made from the soluble form of the human TNF receptor (TNFR),

fused to the Fc component of a human antibody IgG1 domain. Pr-antiTNF has an identical amino acid

sequence to Enbrel .

In vitro and preclinical animal studies have demonstrated that pr-antiTNF exhibits similar activity

to Enbrel . Specifically, pr-antiTNF binds TNF alpha thereby inhibiting it from binding to cellular

surface TNF receptors and protects L929 cells from TNF-induced apoptosis in a dose-dependent

manner. In a proof-of-concept in vivo study using an established arthritis animal model, pr-antiTNF

administered intraperitoneally significantly improved the clinical arthritis parameters associated

with this accepted arthritis mouse model including joint inflammation, swelling and tissue

degradation. Data from the collagen induced arthritis animal model studies are expected to be

presented at an upcoming scientific conference.

We are very encouraged by the preclinical data generated from our pr-antiTNF thus far, said Dr.

Yoseph Shaaltiel, Executive Vice President, R D of Protalix. These data further validate our

ProCellEx technology and its ability to produce a wide range of complex therapeutic proteins in

plant cells. Given our highly efficient and cost effective manufacturing process, we feel the

Company is well positioned to be an active participant in the biosimilar market.

About Protalix BioTherapeutics

Protalix is a biopharmaceutical company. Its goal is to become a fully integrated biopharmaceutical

company focused on the development and commercialization of proprietary recombinant therapeutic

proteins to be expressed through its proprietary plant cell based expression system. Protalix s

ProCellEx(TM) presents a proprietary method for the expression of recombinant proteins that

Protalix believes will allow for the cost-effective, industrial-scale production of recombinant

therapeutic proteins in an environment free of mammalian components and viruses. Protalix completed

a Phase III pivotal study for its lead product candidate, UPLYSO (prGCD), to be used in enzyme

replacement therapy for Gaucher disease, a rare and serious lysosomal storage disorder in humans

with severe and debilitating symptoms. Protalix and the U.S. Food and Drug Administration agreed on

the final design of the pivotal Phase III clinical trial through the FDA s Special Protocol

Assessment (SPA) process. Protalix is also advancing additional recombinant biopharmaceutical drug development programs.

Safe Harbor Statement:

To the extent that statements in this press release are not strictly historical, all such

statements are forward-looking, and are made pursuant to the safe-harbor provisions of the Private

Securities Litigation Reform Act of 1995. These forward-looking statements are subject to known and

unknown risks and uncertainties that may cause actual future experience and results to differ

materially from the statements made. These statements are based on our current beliefs and

expectations as to such future outcomes. Drug discovery and development involve a high degree of

risk. Factors that might cause material differences include, among others, risks relating to: the

successful preclinical development of our product candidates; the completion of clinical trials;

the review process of the FDA, foreign regulatory bodies and other governmental regulation,

including the FDA s review of any filings we make in connection with the treatment protocol; delays

in the FDA s or other health regulatory authorities approval of any applications we file or

refusals to approve such filings; refusals by such regulatory authorities to approve the marketing

and sale of a drug product even after acceptance of an application we file for any such drug

product; the identification of lead compounds; the risk that we may fail to satisfy certain

conditions relating to grants we have received from the Office of the Chief Scientist of Israel s

Ministry of Industry and Trade which may lead to our being required to refund grants previously

received together with interest and penalties; the risk that the Office of the Chief Scientist may

not deliver to us all of the funds awarded to us; uncertainties related to the ability to attract

and retain partners for our technologies and products under development; and other factors

described in our filings with the Securities and Exchange Commission. Under the approved treatment

protocol, UPLYSO (prGCD) might be provided only to a limited number of patients and only for a

limited time. Pharmaceutical and biotechnology companies have suffered significant setbacks in

advanced clinical trials, even after promising results in earlier clinical trials or in preliminary

findings for such clinical trials. The FDA s approval of the treatment protocol for UPLYSO (prGCD)

or the fast track approval will not have any effect on the FDA s approval of any NDA we file with

respect to UPLYSO (prGCD), if any, and the review by the FDA of any data from the Phase III

clinical development programs in connection with the approval of the treatment protocol will not

have any effect on the FDA s subsequent review of our complete Phase III clinical trial data in the

future. The statements are valid only as of the date hereof and we disclaim any obligation to

update this information.

The Trout Group, LLC

Telephone: 646-378-2927

Email: mnanus@troutgroup.com

BMC Communications Group, LLC

Telephone: 212-477-9007 x17

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