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                                                                    EXHIBIT 99.1


FOR IMMEDIATE RELEASE
Contact:  Gary Foster
            (212) 332-2074
            gfoster@antigenics.com


                   ANTIGENICS COMPLETES AQUILA MERGER CREATING
                        PREEMINENT IMMUNOTHERAPY COMPANY


NEW YORK, NEW YORK - NOVEMBER 17, 2000 - Antigenics Inc. (Nasdaq: AGEN)
announced today that it has completed its previously announced merger with
Aquila Biopharmaceuticals, Inc. (Nasdaq: AQLA) effective as of the close of
trading on November 16. Aquila shareholders voted to approve the merger on
November 15. Aquila will now operate as a wholly owned subsidiary of Antigenics.
In connection with the merger, Antigenics will issue approximately 2.5 million
shares of common stock, based on an exchange ratio of 0.2898 shares of
Antigenics stock for each share of Aquila stock.

"We are pleased to complete this merger and see enormous opportunities for
growth as we pursue our vision of creating the world's leading immunotherapy
company," said Garo H. Armen, Ph.D., chairman and CEO of Antigenics. "The
complementary technologies, product pipelines and skill sets of the two
companies give us powerful tools to develop a wide range of immunology
treatments and adjuvants for cancer, infectious diseases and degenerative
disorders."

The merger links Antigenics' superior T-cell activation technology with Aquila's
proven antibody program allowing the combined company to produce treatments
based upon activation of both pathways of the immune system. The combined
company will consist of:

     -    A proprietary heat shock protein (HSP) technology, including
          Oncophage(R), Antigenics' lead cancer vaccinE undergoing testing in a
          phase III clinical trial in kidney cancer and in seven other completed
          or ongoing trials in six different cancer indications. Antigenics
          expects to file an IND with the FDA by the end of the year to begin
          testing Antigenics' HSP technology in the first major infectious
          disease indication.

     -    The Stimulon(TM) program, including QS21, a superior adjuvant that
          forms the basis of several of the company's own products and is
          partnered in multiple late stage clinical trials.

     -    The CD-1 antigen discovery technology for development of vaccines
          based upon a novel immunological pathway.

     -    Leucogen(R), a commercial animal healthcare product for the protection
          against feline leukemia virus.

     -    Corporate partnerships with some of the world's leading pharmaceutical
          and biotechnology companies, including Smith-Kline Beecham,
          Bristol-Myers Squibb and Elan Corp.



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     -    Manufacturing and research facilities in Woburn and Framingham, MA
          giving the company the necessary resources to meet the demands of a
          growing product pipeline in advanced stage development.

     -    A combined workforce of approximately 150 talented scientists,
          researchers, clinicians and other professionals in drug development
          and manufacturing operations.

     -    A strong patent estate with 66 issued patents and over 70 pending
          patents.

     -    A sound financial position that includes over $100 million cash and
          the additional assets from the merger with Aquila that is expected to
          be neutral to additive to the company's cash position for the next two
          years and accretive in 2002 and beyond.

"Employees from Antigenics and Aquila have worked diligently to make this merger
a reality in a short period," Armen said. "We look forward to utilizing the
capabilities of our combined entity to create great value for our shareholders."

Antigenics' therapeutic vaccines for treatment of cancers, infectious diseases
and degenerative disorders are based on it pioneering technology using heat
shock proteins. Antigenics has tested its lead product, Oncophage(R), in five
completed phase I and II clinical trials in colon cancer, melanoma, kidney
cancer and pancreatic cancer, and is now evaluating Oncophage in a phase III
trial in kidney cancer and additional trials in sarcoma, non-Hodgkin's lymphoma
and gastric cancer. Antigenics' other products include: Leucogen(R) for
protection against feline leukemia virus (approved for U.S. and European use in
1991); Quilimmune-P(TM), a human healthcare product iN clinical trials for
prevention of pneumococcal infections in the elderly; Quilimmune-M(TM), a human
healthcare product in clinical trials for prevention of malaria; and
pre-clinical CD1 programs in tuberculosis, Chlamydia infections and cancer. The
company also licenses its immune enhancement technologies, and current partners
include SmithKline Beecham, Elan Corporation, plc, Aventis Pasteur, Wyeth
Lederle, VaxGen, Bristol-Myers Squibb (Progenics Pharmaceuticals), Korea Green
Cross Corporation and Virbac S.A. For more information about the company visit
www.antigenics.com.

NOTE: THE CONFERENCE CALL THAT WAS PREVIOUSLY SCHEDULE FOR TODAY AT 11:00 A.M.
      EST HAS BEEN POSTPONED AND WILL BE RE-SCHEDULED AT A LATER DATE. ##

This press release contains forward-looking statements. These include statements
about the future financial position of Antigenics and its ability to generate
positive cash flows and the potential commercial success of programs in
development. Several risks and uncertainties could cause actual results to
differ materially from those projected in the forward-looking statements. These
factors include the ability to satisfy regulatory requirements, the outcome of
clinical trials, the efficacy of products that are commercialized, the ability
to convince the medical community to adopt products, competition from
pharmaceutical and biotechnology companies, the strength of intellectual
property rights, the ability to raise capital and the risk factors included in
the Antigenics SEC filings.


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