Exhibit 99.1

         TANOX, INC.: FDA ISSUES COMPLETE RESPONSE LETTER FOR XOLAIR

Houston, Texas (July 10, 2001) - Tanox, Inc. (Nasdaq: TNOX), today announced the
receipt by Genentech, Inc. and Novartis AG of a Complete Response letter from
the U.S. Food and Drug Administration (FDA) for their Biologics License
Application (BLA) for XolairTM (Omalizumab), which was filed on June 6, 2000.
In their joint press release, Genentech and Novartis indicated, among other
things, that the letter requests additional preclinical and clinical data
analyses, as well as pharmacokinetic information.  With the requirement of
additional data, they have concluded that there will not be an FDA approval of
Xolair in 2001.  Although no specific deadline has been set for the re-
submissions by Genentech and Novartis, they are considering different scenarios,
with a conservative estimate being resubmissions ranging from 2002 to early
2003.

While no royalty revenues were projected for 2001, this development will have a
significant negative effect on Tanox's estimated revenues for the current year,
which had included an anticipated milestone payment upon the regulatory approval
of Xolair. Michael A. Kelly, Tanox's Vice President and CFO, noted, "This will
also affect projected revenue beyond 2001, and our original expectation for
profitability in 2003 will be delayed. The extent of the delay will depend on
the timing, scope and ultimate approval of the re-submitted BLA by Genentech and
Novartis."

Nevertheless, Tanox expects no effect on its planned operations from the delay
of a prospective milestone payment.  The Company continues to believe that its
cash on hand will be sufficient to fund its operations through 2005.  The
Company is aggressively pursuing development of other products in its pipeline.
Its TNX-901 product is currently in Phase I/II trials for the treatment of
severe peanut allergy.  The Company expects to complete its Phase I safety study
on TNX-100 for Crohn's Disease in the third quarter of 2001.   Tanox anticipates
initiating a Phase I study of TNX-355 for HIV and AIDS within the next two
months.  It also expects to bring TNX-244 into the clinic for ischemia/
reperfusion injury in 2001.

"While today's news is disappointing, we continue to believe that anti-IgE
antibody- technology, on which Xolair is based, will play a significant role in
addressing significant unmet medical needs for the millions of allergy and
asthma sufferers worldwide," said Nancy T. Chang, President and CEO of Tanox.

Tanox, Inc. is a biopharmaceutical company with demonstrated expertise in
monoclonal antibody technology. The Company is engaged in the discovery and
development of therapeutic monoclonal antibodies designed to address significant
unmet medical needs in the areas of asthma, allergy, inflammation and other
diseases affecting the human immune system. Xolair, Tanox's most advanced
product in development, is an anti-immunoglobulin E, or anti-IgE, antibody which
is being developed for allergic asthma, seasonal allergic rhinitis (hay fever)
and perennial allergic rhinitis in collaboration with Novartis Pharmaceutical
Corporation and Genentech, Inc. A BLA for Xolair for allergic asthma and
seasonal allergic rhinitis




has been submitted to the U.S. FDA and a submission for marketing approval has
been filed with health authorities in the EU, Switzerland, Australia and New
Zealand. Tanox is developing a number of monoclonal antibodies to address unmet
medical needs.

Statements in this press release about its products, including Xolair, and their
prospects for development and commercialization, other than statements of
historical facts, are forward-looking statements and are subject to a number of
uncertainties that may cause actual events or results to differ materially from
those suggested in the forward-looking statements. Factors that could affect
actual events or results include risks associated with obtaining regulatory
approval for and market acceptance of Tanox's products, performance by the
Company's present and future collaboration partners, the outcome of pending
litigation, the uncertainty of preclinical and clinical testing results, the
Company's limited experience and capability in manufacturing and marketing the
Company's products, the Company's ability to enter into future collaborations,
competition and technological change, the strength of the Company's patent
portfolio, the Company's ability to manage growth and to attract and retain key
personnel, the Company's access to additional financings in the future, and
existing and future government regulations. Other risks that may affect Tanox
include the variability of royalty, license and other revenues, timelines that
are subject to change, and the unpredictability of decisions by the FDA and
other regulatory agencies, including decisions regarding whether sufficient data
and compliance with other requirements exist to support product licensure.

For further information contact:

Michael A. Kelly - Vice President and CFO -- 713.578.4165
Isabel M. Cordova, The Trout Group - Investor Relations --212.477.9007 x13
Kelly Rose, BMC Communications - Media Relations --212.477.9007 x18

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