Biopharmaceuticals

 News Release - April 3, 2006

Nabi Biopharmaceuticals Acquires Exclusive North American Commercialization Rights to Phase III Antibody Product for Prevention and Treatment of Rejection Following Organ Transplantation

Agreement With Fresenius Biotech for Development and Marketing of ATG-Fresenius S will Significantly Bolster Nabi Biopharmaceuticals' Transplant Franchise

BOCA RATON, Fla., April 3 (HSMN NewsFeed) -- Nabi Biopharmaceuticals (Nasdaq: NABI ) today announced that it has signed an agreement with Fresenius Biotech to advance the development of ATG-Fresenius S in the U.S. and Canada. ATG-Fresenius S is an immunosuppressive polyclonal antibody product used for the prevention and treatment of acute rejection following organ transplantation. The product, which Fresenius currently markets in more than 60 countries worldwide, has been shown to significantly reduce transplant failure and substantially improve survival rates.

Under the terms of the agreement, Fresenius Biotech has granted Nabi Biopharmaceuticals exclusive sales and distribution rights to ATG-Fresenius S in the U.S. and Canada for up to 15 years following the first commercial sale of the product after licensure in the U.S. Nabi Biopharmaceuticals is required to make aggregate milestone payments of $1 million to Fresenius Biotech during development and a $4 million payment upon approval by the U.S. Food and Drug Administration (FDA). Fresenius Biotech will manufacture and supply the product from its European facility in exchange for a royalty. Nabi Biopharmaceuticals will be responsible for the clinical development, regulatory approval process, marketing and sales of ATG-Fresenius S in the U.S. and Canada.

In January 2005, the FDA granted Fast Track Status for ATG-Fresenius S in lung transplantation. As a result of its agreement with Fresenius Biotech, Nabi Biopharmaceuticals will assume oversight of an ongoing randomized, double-blind, placebo-controlled Phase III clinical study that is being conducted in lung transplant patients in the U.S. and Europe. The company may also undertake additional studies to expand the indications into other areas, such as bone marrow transplantation. Based on the outcome of its upcoming meeting with the FDA, and assuming all regulatory and clinical milestones are met, Nabi Biopharmaceuticals expects to file its Biologics License Application (BLA) for ATG-Fresenius S in early 2009.

Thomas H. McLain, chairman, chief executive officer and president, Nabi Biopharmaceuticals, stated, "This agreement represents an exciting opportunity for Nabi Biopharmaceuticals to leverage our proven strengths in marketing specialized antibody products to commercialize a drug that has been used in the treatment of more than 150,000 transplant patients around the world. It is also an important step forward in our strategy to become a leading provider of products that improve both the longevity and the quality of life of transplant patients."

Dr. Thomas Gottwald, chief executive officer, Fresenius Biotech, stated, "We are very pleased to have found an experienced partner in transplantation medicine that can continue and expand the current clinical development program of ATG-Fresenius S. Nabi Biopharmaceuticals created what today is a very favorable commercial product in Nabi-HB, the current gold standard in the U.S. for prevention of re-infection with hepatitis B in liver transplant patients."

Strategic Importance

Clinical Need

In 2004, over 26,000 solid organ transplants were conducted in the U.S., and solid organ transplants in the U.S. have been increasing at an annual rate of four percent per year. More than 60 percent of these procedures involve the replacement of a kidney and 23 percent are for liver transplants. Nabi Biopharmaceuticals' transplant franchise is focused on addressing the critical, unmet medical needs of this sizeable and growing population, and ATG-Fresenius S is a highly complementary addition to the company's existing product offering.

Competitive Product

A number of European-based studies conducted to date have shown that ATG- Fresenius S targets the cells responsible for organ rejection better than competing products. Nabi Biopharmaceuticals believes that the limited side effects, better patient tolerance and convenient dosing regimen associated with ATG-Fresenius S, will make it a highly attractive alternative to other products that are currently on the market.

Professor Emeritus Dr. Walter Land, University Hospital Munich Grosshadern in Germany, one of Europe's most highly-regarded transplant surgeons and a leading international authority in the field of transplant medicine, said, "ATG-Fresenius S is a safe and highly efficacious product that, in combination with standard immunosuppressive drugs, significantly improves the long-term survival prognosis of organ graft and transplant patients."

Low Risk/High Reward Potential

By drawing on its core competencies in the development, manufacture and commercialization of polyclonal antibodies, as well as its strong relationships with key opinion leaders, physicians, payers and patients across the transplant community, Nabi Biopharmaceuticals is uniquely positioned to maximize the considerable value-creation potential of ATG-Fresenius S in North America. In addition, ATG-Fresenius S complements the company's existing development infrastructure and leverages the value of existing internal development resources.

The foundation of Nabi Biopharmaceuticals' transplant franchise is Nabi- HB® [Hepatitis B immune globulin (Human)], a polyclonal antibody product that is indicated to prevent hepatitis B infection following accidental exposure to the hepatitis B virus, but is primarily used to prevent re- infection with hepatitis B virus in HBV-positive liver transplant patients. Nabi Biopharmaceuticals' complementary product, Civacir® [Hepatitis C immune globulin (Human)], is being developed to prevent re-infection with the hepatitis C virus in hepatitis C liver transplant patients. A Phase II proof- of-concept clinical trial for Civacir is planned for the second half of 2006.

Mechanism of Action

In contrast to other immunosuppressive agents, ATG-Fresenius S works by selective suppression of activated cells, which are responsible for the rejection of transplanted organs. Transplant rejection occurs when the immune system of the patient attacks the newly transplanted organ or tissue from another donor. Rejection occurs because a normal healthy human immune system can distinguish foreign tissues and attempts to destroy them.

About Nabi Biopharmaceuticals

Nabi Biopharmaceuticals leverages its experience and knowledge in powering the immune system to develop and market products that fight serious medical conditions. The company has three products on the market today: PhosLo® (calcium acetate), Nabi-HB® [Hepatitis B immune globulin (Human)], and Aloprim(TM) (allopurinol sodium) for Injection. Nabi Biopharmaceuticals is focused on developing products that address unmet medical needs and offer commercial opportunities in our core business areas: Gram-positive bacterial infections, hepatitis, kidney disease (nephrology) and nicotine addiction. For a complete list of pipeline products, please go to: http://www.nabi.com/pipeline/index.php . The company is headquartered in Boca Raton, Florida. For additional information about Nabi Biopharmaceuticals, please visit our website at: http://www.nabi.com .

About Fresenius Biotech GmbH

Fresenius Biotech GmbH is a company of the Fresenius Health Care Group, focused on the development and marketing of biopharmaceuticals in the fields of oncology, immunology and regenerative medicine.

Statements in this press release about the company that are not strictly historical are forward-looking statements and include statements about our products in development, the market for such products, clinical trials and studies, intellectual property position, and alliances and partnerships. You can identify these forward-looking statements because they involve our expectations, beliefs, plans, projections, or other characterizations of future events or circumstances. These forward-looking statements are not guarantees of future performance and are subject to risks and uncertainties that may cause actual results to differ materially from those in the forward- looking statements as a result of any number of factors. These factors include, but are not limited to, risks relating to the company's ability to advance the development of products currently in the pipeline or in clinical trials; maintain the human and financial resources to commercialize current products and bring to market products in development; obtain regulatory approval for its products in the U.S., Europe or other markets; successfully develop, manufacture and market its products; realize future sales growth for its biopharmaceutical products; secure patent positions and prevail in patent litigation; raise additional capital on acceptable terms; and re-pay its outstanding convertible senior notes when due. Many of these factors are more fully discussed, as are other factors, in the company's Annual Report on Form 10-K for the fiscal year ended December 31, 2005 filed with the Securities and Exchange Commission.

Source: Nabi Biopharmaceuticals

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