XOMA CONTACTS: Ellen M. Martin
                         510-644-1170 or 800-BIO XOMA
                         Thomson IR: Juliane Snowden 212-510-9286


XOMA COMPLETES $30.7 MILLION COMMON SHARE FINANCING

Berkeley, CA - February 14, 2000 - XOMA Ltd. (Nasdaq: XOMA) today announced it
has sold 6.1 million common shares in a private placement to a number of
institutional investors for gross proceeds of $30.7 million. Arnhold and S.
Bleichroeder, Inc. and Sutro & Co. Incorporated served as placement agents for
the transaction.

"We are very pleased with the reception we received for this financing," said
Peter B. Davis, Vice President of Finance and CFO of XOMA. "We attracted
high-quality institutional investors and demand was such that we increased the
funding above our original target level. The collaboration, licensing and supply
agreements concluded in the past year with Genentech, Allergan and, most
recently, Baxter have reduced our burn rate. These relationships plus this
financing improve our financial position considerably over that of recent
years."

"This week's financing represents a significant increase in our level of
institutional investment," said Jack Castello, Chairman, President and CEO of
XOMA. "We now have approximately two years of cash on hand to support continuing
research on promising opportunities that could further enhance the value of the
company."

Financing proceeds will be used primarily to fund development of products from
XOMA's monoclonal antibody and BPI (bactericidal/permeability-increasing
protein) development platforms. Monoclonal antibody products in XOMA's research
pipeline include ING-1, an antibody that may be useful in treating a variety of
solid tumor cancers, and Genimune(TM), a targeted gelonin fusion product
candidate for treatment of immune cell cancers and autoimmune diseases. Internal
BPI development programs include Mycoprex(TM), a BPI-derived fungicidal
compound, and anti-angiogenic BPI peptide-derived compounds.

XOMA develops and manufactures biopharmaceuticals at facilities located in
Berkeley and Santa Monica, California. Medical targets include infectious
diseases, immunologic and inflammatory disorders, and cancer. The Company has
extensive experience developing monoclonal antibodies. XOMA is collaborating
with Genentech in developing the anti-CD11a humanized monoclonal antibody
product. A Phase III trial was started in patients with moderate to severe
plaque psoriasis in December 1999 and plans have been announced to perform a
Phase I/II study in kidney transplant patients. In addition to the ING-1 and
Genimune(TM) products, XOMA owns a patented method for antibody humanization,
and has developed a cell expression system for manufacturing recombinant
proteins (including antibodies) that has been licensed to more than 15
biotechnology and pharmaceutical companies worldwide.




XOMA's primary infectious disease drug development platform is BPI
(bactericidal/permeability-increasing protein), a human protein with multiple
anti-infective properties that is part of the body's defense system against
microbial infection. BPI was discovered in white blood cells by Peter Elsbach,
MD, and Jerrold Weiss, PhD, at New York University School of Medicine (NYU).
XOMA has collaborated with NYU since 1991 to extend and apply BPI-related
research to pharmaceutical development. XOMA recently entered into a licensing
arrangement with Baxter Healthcare's Hyland Immuno Division to continue
development of the NEUPREX(R) (rBPI21) product in meningococcemia and other
anti-bacterial and anti-endotoxin indications. In 1999, XOMA completed a Phase
III trial of NEUPREX(R) in meningococcemia, a deadly systemic bacterial
infection that primarily attacks children. The Company also has an agreement
with Allergan to develop BPI/antibiotic ophthalmic anti-infective products.

For more information, visit XOMA's web site at www.xoma.com

Statements made in this press release related to the sufficiency of the
Company's cash position, timing of clinical trials, the FDA regulatory process,
collaborative relationships, other aspects of 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.
These risks, including those related to the timing or results of pending or
future clinical trials, changes in the status of the Company's collaborative
relationships, uncertainties regarding the legal standards applicable to
biotechnology patents, and actions by the U.S. Food and Drug Administration or
the U.S. Patent and Trademark Office, are discussed in the Company's most recent
annual report on Form 10-K and in other SEC filings. Consider such risks
carefully in evaluating XOMA's prospects.

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