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THP and SangStat Partner to Develop Humanized Polyclonal Antibody Drugs

11.11.2002

Sunnyvale, Calif. – Nov 11, 2002

Therapeutic Human Polyclonals Inc., a biotechnology company, has entered a multiproduct collaboration with SangStat Medical Corporation to commercialize the first humanized polyclonal antibodies for human diseases. The collaboration combines THP’s novel approach to produce humanized polyclonal antibodies in rabbits with Sangstat’s global leadership in polyclonal-based therapeutics from animals. Resulting products could revolutionize the treatment of disease.

The first product in the collaboration is a humanized version of SangStat’s Thymoglobulin®. While Thymoglobulin® (Anti-thymocyte Globulin, [Rabbit]) is highly effective in treating acute organ rejection in transplant patients, its use in immunocompetent individuals is currently limited due to reactivity against rabbit proteins. The second-generation Thymoglobulin® will be human in composition and compatible with the patient’s immune system, making repeated administrations safe and effective. Repeat dosing would enable wider use of humanized Thymoglobulin® in organ transplant rejection and other indications including autoimmune disease and cancer. Under the agreement, THP and SangStat also plan to codevelop additional humanized polyclonal drugs to address needs in oncology with a focus on hematology.

“THP has been building its platform for the past few years and is now ready to expand into the development of specific products for infectious diseases and cancer,” said THP Co-founder and Chief Executive Officer Wim van Schooten, Ph.D. “THP believes that it will be the first company to bring humanized polyclonal antibody preparations from genetically engineered animals to the market. With SangStat’s manufacturing, sales and marketing expertise, THP will establish a leadership position in the field of polyclonal antibody therapeutics.”

SangStat’s commitment to THP includes an equity investment and additional payments related to product commercialization. Under the equity investment, SangStat is a co-investor with Research Corporation Technologies of Tucson, Ariz., in a two-stage financing worth $10 million. After this round, SangStat alone will have the option to invest $15 million more as THP’s technology matures. For each product developed under the collaboration, SangStat will pay license fees, royalties and clinical milestones. Additionally, SangStat will give THP the opportunity to share in the profits of hematologic products by opting to share development costs. Sangstat’s total commitment to THP in equity and product collaborations could reach $45 million over several years. This deal follows an initial investment in THP by RCT, which incubated the Company with THP Founders Roland Buelow, Ph.D., and van Schooten.

“RCT fully supported THP with monies and expertise to build its platform for the past two years and will continue to support this revolutionary approach to treating diseases,” said Shaun Kirkpatrick, RCT Vice President and THP Chairman. “This collaboration not only brings an ideal partner and investor to THP but gives THP an important ability to participate in a potentially significant stream of revenue through profit sharing.”

Antibodies have become an important class of pharmaceutical products due to humanization technologies that eliminate unwanted side effects of animal-derived antibodies. Numerous biopharmaceutical companies have advanced human-like monoclonals through clinical trials and to the market, yet no one has successfully applied these technologies to polyclonals.

THP has created the PolyTarg™ platform to expand the use of antibody therapeutics from single-specificity monoclonal antibodies to polyclonal drugs with greater use. As with monoclonal drugs, humanized polyclonals are highly specific but more versatile, capable of targeting complex multi-antigenic targets insufficiently addressed by monoclonal therapies. Examples abound of bacterial and viral resistance to high-potency antibiotics, and malignant cancers that gain resistance to standard anticancer drugs and monoclonal antibody therapies.

THP’s PolyTarg™ platform involves a novel genetic-engineering approach that enables production of affinity-matured humanlike polyclonal antibodies in large animals. The company’s scalable PolyTarg™ platform can be applied to several different indications to produce highly specific humanized polyclonal drugs rapidly and efficiently. THP works closely with Munich collaborators Professor Eckard Wolf at Ludwig-Maximilians-Universität and Professor Gottfried Brem at Agrobiogen GmbH. THP plans to expand its operations in California and Germany as a result of the SangStat collaboration.

“The collaboration between SangStat and THP represents an historic and logical step in the development and use of antibodies to fight disease,” said Richard D. Murdock, interim Chairman, President and CEO. “Just as the development of humanized monoclonal antibodies represented a significant medical advance, we believe the development of humanized polyclonal antibodies, if successful, will prove to be a watershed event in medical science.”

In support of the collaboration between THP and SangStat, Buelow, former Senior Vice President of Discovery Research at SangStat, will join THP as Chief Scientific Officer effective immediately. At SangStat, Buelow headed the development of RDP58, a novel anti-inflammatory compound that is now in Phase II studies in Europe. Also, Buelow’s research team worked on Thymoglobulin®, the leading polyclonal antibody product in solid organ transplantation, and outselling humanized monoclonal antibodies like Simulect® and Zenapax®.

“Thymoglobulin® is a beautiful example of the power of polyclonal antibody therapy,” Buelow said. “THP’s PolyTarg™ technology will take polyclonal antibody therapy to the next dimension, similar to what humanization has done for monoclonals in the 80s and 90s.”

About Therapeutic Human Polyclonals Inc.

Therapeutic Human Polyclonals Inc. is a biotechnology company developing a platform to produce the next-generation antibody therapy. THP’s headquarters are in Sunnyvale, California. THP has a wholly owned subsidiary, THP GmbH in Munich, Germany. The company’s web site is located at www.polyclonals.com.

About SangStat

SangStat is a global biotechnology company focused on immunology and working to discover, develop and market high-value therapeutic products in the autoimmune, hematology/oncology and immunosuppression areas. SangStat’s U.S. headquarters are in Fremont, Calif. SangStat also maintains a strong European presence, including direct sales and marketing forces in France, Germany, Italy, Spain and the United Kingdom, and distributors throughout the rest of the world. SangStat’s stock is traded on the Nasdaq under the symbol “SANG.” The company’s web site is located at www.sangstat.com.

About Research Corporation Technologies

Research Corporation Technologies is an independent technology management company that commercializes early-stage biomedical and photonics technologies worldwide. Commercialization vehicles include seed investments and venture development, partnerships, and specialized licensing programs. The Company’s web site is located at www.rctech.com.

Contact

Jan McCoy Hutchinson, Director, RCT and THP Communications, (520) 748-4458. Bill Martin, Director, SangStat Corporate Communications, (510) 789-4331 or (510) 703-2844 (mobile).