Nabi Biopharmaceuticals Announces Positive Interim Results of NicVAX Immunogenicity...

Nabi Biopharmaceuticals Announces Positive Interim Results of NicVAX
Immunogenicity Study

ROCKVILLE, Md., July 23, 2008 (PRIME NEWSWIRE) -- Nabi Biopharmaceuticals
(Nasdaq:NABI) announced today positive interim results from its Phase 2
NicVAX(r) (Nicotine Conjugate Vaccine) schedule optimization immunogenicity
study to assess the antibody response and safety of a 400 microgram, six dose
immunization schedule.

Interim results from the study indicate that significantly higher anti-nicotine
antibody levels can be generated three months earlier and in a much higher
percentage of subjects than observed in previous NicVAX studies. Nabi's new
immunization schedule, which included an additional injection at three months,
resulted in an immune response at 14 weeks that was higher than the peak
antibody level achieved following the six month booster in the Phase 2b proof of
concept study. Significantly, the data indicated that more than 80% of subjects
achieved the target antibody level at 14 weeks compared to 50% of subjects in
the Phase 2b proof of concept study at the same time point. The revised schedule
was well tolerated with an adverse event profile comparable to previous NicVAX
clinical studies.

"We are excited that these initial results strongly support our hypothesis that
production of anti-nicotine antibodies can be accelerated and elevated with this
revised regimen," stated Dr. Raafat Fahim, President and Chief Executive Officer
of Nabi Biopharmaceuticals. "The Phase 2b proof-of-concept trial results,
completed in November 2007, demonstrated a clear and positive correlation
between antibody levels and the ability of patients to quit smoking and remain
abstinent. We believe that significantly enhancing the antibody levels in the
majority of immunized subjects would increase the likelihood of success in the
upcoming pivotal studies. The final results of the current immunogenicity study
will provide critically important information that will be incorporated into the
design of the Phase 3 clinical trials. Phase 3 is on track to be initiated
before the end of this year."

About NicVAX

NicVAX(r) is an innovative and proprietary investigational vaccine being
developed by Nabi to treat nicotine addiction and prevent smoking relapse.
NicVAX(r) is designed to stimulate the immune system to produce antibodies that
bind to nicotine. A nicotine molecule attached to an antibody is too large to
cross the blood-brain barrier. Therefore, NicVAX(r) blocks nicotine from
reaching its receptors in the brain and prevents the highly-addictive pleasure
sensation experienced by smokers and users of nicotine products. Pre-clinical
and previous clinical data, as well as the study reported here, show that
NicVAX(r)'s ability to block nicotine from reaching the brain could help people
quit smoking. Because the body's immune system can be boosted to produce
long-lasting antibodies, Nabi believes NicVAX(r) also could be effective in
preventing smoking relapse. Relapse is a significant challenge facing smokers
and, with currently-available smoking cessation therapies, relapse rates can be
as high as 90% in the first year after a smoker quits.

About Nabi Biopharmaceuticals

Nabi Biopharmaceuticals leverages its experience and knowledge in powering the
immune system to develop products that target serious medical conditions in the
areas of nicotine addiction and gram-positive bacterial infections. Nabi
Biopharmaceuticals is currently developing NicVAX(r) (Nicotine Conjugate
Vaccine), an innovative and proprietary investigational vaccine for treatment of
nicotine addiction and prevention of smoking relapse, and PentaStaph(tm)
(Pentavalent S. aureus Vaccine), a vaccine designed to prevent the most
dangerous and prevalent strains of S. aureus bacterial infections. The company
is headquartered in Rockville, Maryland. For additional information about Nabi
Biopharmaceuticals, please visit our Web site:http://www.nabi.com.

Forward-Looking Statements

Statements in this release that are not strictly historical are forward-looking
statements including statements about NicVAX. You can identify these
forward-looking statements because they involve our expectations, beliefs,
projections, anticipations 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 our ability to: successfully pursue strategic and other
alternatives; conduct clinical trials and obtain successful clinical trial
results; receive PhosLo milestone and royalty proceeds; successfully partner
with third parties to fund, develop, and manufacture our pipeline products,
including NicVAX and our gram-positive infections products; realize anticipated
cost saving; attract and maintain the human and financial resources to bring to
market products in development; depend upon third parties to manufacture our
products; achieve approval and market acceptance of our products; enter into and
maintain arrangements with third parties to market and sell our products; comply
with reporting and payment obligations under government rebate and pricing
programs; raise additional capital on acceptable terms, or at all; and re-pay
our 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 29, 2007 and our Quarterly Report
for the quarter ended March 29, 2008 on form 10-Q that have been filed with the
Securities and Exchange Commission.

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CONTACT: Nabi Biopharmaceuticals
Investor Relations
301-770-3099
www.nabi.com