XOMA Discovers Two New Classes of Insulin Receptor-Regulating Antibodies

Mon Jun 27, 2011 8:03am EDT

* Reuters is not responsible for the content in this press release.

SAN DIEGO, June 27, 2011 (GLOBE NEWSWIRE) -- XOMA Ltd. (Nasdaq: XOMA), a leader
in the discovery and development of therapeutic antibodies, announced the first
presentation of results from its discovery of two new classes of fully human
monoclonal antibodies that activate or sensitize the insulin receptor in vivo,
each representing a distinct new therapeutic approach to the treatment of
patients with diabetes. The data were presented at the American Diabetes
Association 71st Scientific Sessions in San Diego.

Insulin is the key metabolic hormone for regulating blood sugar and exerts its
action on cells by signaling through the insulin receptor. Alterations in
insulin signaling occur in Type 2 diabetes and its precursor, metabolic
syndrome. Highly specific human antibodies that activate or sensitize the
insulin receptor offer new direct mechanisms for treating different aspects of
the diabetes disease spectrum.

Insulin receptor-activating antibodies such as XOMA's XMetA antibody are
designed to provide long-acting insulin-like activity to diabetic patients who
cannot make sufficient insulin, potentially reducing the number of insulin
injections needed to control their blood glucose levels.  In contrast, insulin
receptor-sensitizing antibodies such as XOMA's XMetS are designed to reduce
insulin resistance and could enable diabetic patients to more effectively use
their own insulin to control blood glucose levels.

Studies presented on the XMetA antibody demonstrated that it reduced fasting
blood glucose levels and improved glucose tolerance in a mouse model of
diabetes.  After six weeks of treatment, there was a statically significant
reduction in hemoglobin A1c levels, a standard measure of average blood glucose
levels over time, in mice treated with XMetA compared to control. In addition,
there was a statistically significant reduction in elevated non-HDL cholesterol

Studies of the XMetS antibody in a mouse model of obesity-induced insulin
resistance showed enhanced insulin sensitivity and statistically significant
improvements in fasting blood glucose levels and glucose tolerance in mice
treated with XMetS as compared to control. In addition, there was a
statistically significant reduction in elevated non-HDL cholesterol levels.

Presentation details:

High Affinity Partial Agonist Insulin Receptor Antibodies Stimulate Insulin
Activity and Improve Glycemic Control in Murine Models of Diabetes; ADA Abstract
No. 0417-PP presented during General Poster Session III

High Affinity Insulin Receptor Antibodies Sensitize the Insulin Receptor to
Insulin and Restore Glycemic Control in Murine Models of Diabetes; ADA Abstract
No. 1008-P presented during Pharmacologic Treatment of Diabetes -- Novel
Therapies III

About XOMA

XOMA is a leader in the discovery and development of novel antibody
therapeutics. The company's proprietary product pipeline includes:

  --  XOMA 052, a potentially best-in-class antibody that binds to the
      inflammatory cytokine interleukin-1 beta, or IL-1 beta. XOMA plans to
      enter XOMA 052 into Phase 3 clinical development in Behcet's uveitis, an
      orphan indication. Les Laboratoires Servier is XOMA's development and
      commercialization partner for XOMA 052.   

  --  XOMA 3AB, a novel combination of three antibodies to prevent and treat
      botulism poisoning caused by exposure to botulinum neurotoxin Type A,
      among the most deadly bioterror threats. XOMA 3AB is in a Phase 1
      clinical trial sponsored by the National Institute of Allergy and
      Infectious Diseases (NIAID) of the National Institutes of Health (NIH).
      The XOMA 3AB project has been funded in whole or in part with funds from
      NIAID, NIH, Department of Health and Human Services under Contract No.
      HHSN266200500004C, Contract No. HHSN266200600008C and Contract No.

  --  A preclinical pipeline with candidates in development for autoimmune,
      cardio-metabolic, inflammatory and oncologic diseases.

XOMA has a premier antibody discovery and development platform that incorporates
an unmatched collection of antibody phage display libraries and proprietary
optimization and expression and manufacturing technologies that it uses for its
own pipeline and in collaborations with pharmaceutical and biotechnology
companies. XOMA technologies have contributed to the success of marketed
antibody products including LUCENTIS(R) for wet age-related macular degeneration
and CIMZIA(R) for rheumatoid arthritis and Crohn's disease. XOMA's fully
integrated product development infrastructure extends from preclinical science
to approval and is located in Berkeley, California. For more information, please
visit www.xoma.com.

The XOMA Ltd. logo is available at

Forward-Looking Statements

Certain statements contained herein concerning product development or that
otherwise relate to future periods are forward-looking statements within the
meaning of Section 27A of the Securities Act of 1933 and Section 21E of the
Securities Exchange Act of 1934. These statements are based on assumptions that
may not prove accurate. Actual results could differ materially from those
anticipated due to certain risks inherent in the biotechnology industry and for
companies engaged in the development of new products in a regulated market.
Among other things, results of early-stage clinical trials may not be supported
by later findings, larger trials and/or other actions required for regulatory
approval may not be economically feasible, and results of clinical trials may in
any event not be consistent with preclinical or interim results.

These and other risks, including the generally unstable nature of current
economic and financial market conditions; the results of discovery research and
preclinical testing; the timing or results of pending and future clinical trials
(including the design and progress of clinical trials; safety and efficacy of
the products being tested; action, inaction or delay by the FDA, European or
other regulators or their advisory bodies; and analysis or interpretation by, or
submission to, these entities or others of scientific data); changes in the
status of existing collaborative and licensing relationships; the ability of
collaborators, licensees and other third parties to meet their obligations;
XOMA's ability to meet the demands of the United States government agency with
which it has entered into its government contracts; competition; market demands
for products; scale-up and marketing capabilities; availability of additional
licensing or collaboration opportunities; international operations; share price
volatility; XOMA's financing needs and opportunities; uncertainties regarding
the status of biotechnology patents; uncertainties as to the costs of protecting
intellectual property; and risks associated with XOMA's status as a Bermuda
company, are described in more detail in XOMA's most recent filing on Form 10-K
and in other SEC filings. Consider such risks carefully when considering XOMA's

         Company and Investor Contact:
         Carol DeGuzman

         Canale Communications
         Media Contact:
         Carolyn Hawley