Exhibit 99.1

     Antigenics Announces Results from In-Depth Analysis of Phase 3 Data of
           Oncophage in Kidney Cancer and Provides Regulatory Update


    NEW YORK--(BUSINESS WIRE)--June 7, 2006--Antigenics:

    --  A 43-Percent Improvement Shown in Recurrence-Free Survival in
        Large Group of Earlier-Stage Kidney Cancer Patients Who
        Received Oncophage

    --  Antigenics Will Continue to Follow Patients for Overall
        Survival

    --  Conference Call to Be Held at Today at 9:00 A.M. ET

    Antigenics, Inc. (NASDAQ: AGEN) today announced that it has
completed an in-depth analysis of its Phase 3 study of Oncophage(R)
(vitespen) vaccine in kidney cancer. Review of the data at an
international expert panel meeting on June 2, 2006, found that in the
full analysis set* (FAS, which represents the true adjuvant patient
population intended for the trial), there was a clinically significant
improvement in recurrence-free survival (RFS) associated with
Oncophage in a well defined subgroup of better-prognosis FAS patients.
   It is in this large group of 361 patients - or 60 percent of the
total FAS population - that the greatest apparent response to
Oncophage versus the observation arm was observed (nominal, two-sided
P value of 0.018). In addition, the hazard ratio for this group was
0.567, indicating that patients receiving Oncophage had a 43-percent
decreased risk of recurrence compared with patients in the observation
arm. This better-prognosis subgroup includes patients whose disease
was stage I (high-grade), stage II (high-grade), and stage III T1, T2
and T3a (low-grade), as defined by the American Joint Committee on
Cancer (AJCC).
   "These analyses have identified a clinically relevant adjuvant
patient population that appears more responsive to treatment with
Oncophage," said Christopher G. Wood, MD, associate professor of
urology at M. D. Anderson Cancer Center in Houston, and lead
investigator of the trial. "These results certainly warrant further
exploration of the use of Oncophage in kidney cancer patients."
   "The substantial improvement observed in the better-prognosis
patients - who account for a significant proportion of the total
enrolled in this trial - further support the clinical and preclinical
findings on Oncophage generated to date," said Garo H. Armen, PhD,
chairman and CEO of Antigenics. "Clearly, cancer vaccines work
differently than other cancer drugs. Their effect is best measured on
earlier-stage patients, which is consistent with signs of clinical
activity with a number of other vaccines being studied in the clinic."

   Study Findings

   The Phase 3, randomized, international, multicenter, open-label
trial (C-100-12) involved 728 patients whose renal cell carcinoma (the
most common type of kidney cancer) was at high risk of recurrence
after nephrectomy (surgical removal of the diseased kidney). A
subsequent independent review by the trial's Clinical Events Committee
(CEC), comprised of three radiologists and one oncologist, found that
124 patients had disease at baseline; consequently, 604 of the 728
randomized patients were eligible for analysis of the study's primary
endpoint, recurrence-free survival.
   Per protocol, the study population included those with stage I
(high-grade), stage II (high-grade), stage III and stage IV
(nonmetastatic) disease. Patients were randomized in a 1:1 ratio into
two arms: nephrectomy plus Oncophage vaccination (treatment arm), or
nephrectomy alone (observation arm). The arms were well balanced for
all known prognostic factors.
   Primary analysis of study endpoints focused on the FAS population
(the 604 patients who did not have radiologically apparent disease
postsurgery). Results reported previously in March 2006 had indicated
a trend in favor of recurrence-free survival for the Oncophage arm in
the overall patient population. The Kaplan-Meier curve (an estimate of
the cumulative probability of recurrence-free survival) below shows
that following additional analysis of the data, there was a clinically
significant improvement in recurrence-free survival for
better-prognosis patients in the FAS population (stages I
(high-grade), II (high-grade), and III T1, T2 and T3a (low-grade)) in
the Oncophage arm compared with the observation arm (nominal,
two-sided P value of 0.018).
   In addition to the overall and better-prognosis FAS populations,
analysis showed a trend in favor of Oncophage for recurrence-free
survival in the intent-to-treat (ITT), randomized eligible set (mITT)
and evaluable population sets.
   Overall survival, the secondary endpoint of the study, was also
assessed in the 604 patients included in the FAS population.
Preliminary analysis indicates a trend against Oncophage; however, the
survival data are immature. The company believes the data are also
likely influenced by missing information caused by patients who were
lost to follow-up or withdrew consent. At the time of data cut-off in
January 2006, 31 patients (10.3 percent) had died in the Oncophage arm
versus 22 patients (7.2 percent) in the observation arm. As of May
2006, seven additional deaths have been reported, with only two in the
Oncophage arm and five in the observation arm. Antigenics continues to
collect and analyze survival data from the trial.
   Adverse events reported during the trial were generally mild and
expected. The more frequently reported adverse events were mainly
constitutional in nature or related to the actual injection, and
included, but were not limited to, injection site erythema, injection
site induration, injection site pain, injection site edema, headache,
fatigue and rash.

   Antigenics Announces Results of Discussions With FDA

   Antigenics also announced that it met with the US Food and Drug
Administration (FDA) on May 23, 2006, to discuss the regulatory
pathway for Oncophage in kidney cancer. As a result of these
discussions, Antigenics will continue to follow patients for overall
survival and undertake all efforts to collect missing information on
patients lost to follow-up or who withdrew consent.

   Conference Call Information

   Antigenics executives and Ronald Bukowski, MD, director of
experimental therapeutics and the Phase 1 clinical trials unit at the
Cleveland Clinic's Taussig Cancer Center, and an investigator on the
study, will host a conference call at 9:00 a.m. ET today. To access
the live call, dial 888.271.9082 (domestic) or 706.679.7741
(international); the access code is 1262251. The call will also be
webcast and will be accessible from the company's website at
www.antigenics.com/webcast/. A replay will be available approximately
two hours after the call through midnight ET on June 21, 2006. The
replay number is 800.642.1687 (domestic) or 706.645.9291
(international), and the access code is 1262251. The replay will also
be available on the company's website approximately two hours after
the live call.

   AJCC Staging

   Staging is the process of finding how far the cancer has spread.
In general, lower stages are associated with better prognoses. Within
each stage are further distinctions for the tumor, involvement of
lymph nodes and metastases. The following are simplified definitions
of the various stages of kidney cancer.
   Stage I: The primary cancer is 7 centimeters (about 3 inches) or
less, and is limited to the kidney, with no spread to lymph nodes or
distant sites.
   Stage II: Still considered an early stage, the primary cancer is
greater than 7 centimeters and is limited to the kidney, with no
spread to lymph nodes or distant sites.
   Stage III: The primary cancer is less than or greater than 7
centimeters, but may have spread to a single regional lymph node. The
primary tumor may extend to the renal veins or vena cava (large vein
returning blood to the heart located in the middle of the abdomen near
the back), but has only extended directly and not out of the local
area of the kidney. T1, T2, T3 and T4 designations describe the size
of the tumor and the degree to which it extends beyond the local area
of the kidney.
   Stage IV: The cancer has spread to more than one lymph node,
nearby organs, such as the pancreas or bowel, or to other parts of the
body, such as the lungs.

   About Renal Cell Carcinoma

   Renal cell carcinoma is the most common type of kidney cancer. The
American Cancer Society estimates that there will be approximately
38,890 new cases of kidney cancer in the United States in 2006, and
about 12,840 people will die from the disease in 2006. Renal cell
carcinoma accounts for about 90 percent of all kidney tumors. By the
time renal cell carcinoma is diagnosed in these patients, about one
third of them will have developed metastatic disease.
   The current standard of care for patients with nonmetastatic renal
cell carcinoma consists of a nephrectomy (surgical removal of the
kidney) followed by observation. There is no FDA-approved treatment
for nonmetastatic renal cell carcinoma at the present time.

   About Antigenics

   Antigenics is a biotechnology company working to develop
treatments for cancers, infectious diseases and autoimmune disorders.
The company's investigational product portfolio includes Oncophage(R)
(vitespen), a patient-specific therapeutic cancer vaccine being
evaluated in several indications; Aroplatin(TM) (L-NDDP), a liposomal,
third-generation platinum chemotherapeutic; ATRA-IV, a liposomal
retinoic acid; AG-707, a therapeutic vaccine for the treatment of
genital herpes; AU-801, a preclinical program targeting autoimmune
disorders; and QS-21, an adjuvant being evaluated by Antigenics'
corporate partners in several late-stage clinical trials. For more
information, please visit www.antigenics.com.
   *As defined by FDA-issued guidance (ICH E9: Statistical Principles
for Clinical Trials), the full analysis set is the set of subjects
that is as close as possible to the ideal implied by the
intention-to-treat principle. It is derived from the set of all
randomized subjects by minimal and justified elimination of subjects.

   This press release contains forward-looking statements, including
statements regarding the potential clinical benefit of Oncophage in
kidney cancer based on a subgroup analysis; the planned future data to
be collected and analyzed in connection with the future development of
Oncophage; and the expectation that the survival data collected to
date in this trial are inconclusive and immature. These
forward-looking statements are subject to risks and uncertainties that
could cause actual results to differ materially. These risks and
uncertainties include, among others, unfavorable data resulting from
further analysis of the Oncophage Phase 3 Part 1 trial data; retention
of key employees engaged in activities related to the future
development of Oncophage; the risk that survival data from patients
that withdrew from the study or were lost to follow-up may not be
available for collection or review, or that future survival data from
patient monitoring may not support further development or registration
of Oncophage; decisions by regulatory agencies that delay or prevent
further clinical trials of Oncophage; the ability to raise capital and
finance future development of Oncophage; and the factors described
under Factors That May Impact Future Results in the Management's
Discussion and Analysis of Financial Condition and Results of
Operations section of Antigenics' Form 10-Q as filed with the
Securities and Exchange Commission on May 12, 2006. Antigenics
cautions investors not to place considerable reliance on the
forward-looking statements contained in this press release. These
statements speak only as of the date of this document, and Antigenics
undertakes no obligation to update or revise the statements. All
forward-looking statements are expressly qualified in their entirety
by this cautionary statement. Antigenics' business is subject to
substantial risks and uncertainties, including those identified above.
When evaluating Antigenics' business and securities, investors should
give careful consideration to these risks and uncertainties.


    CONTACT: Antigenics
             Media Relations:
             Sunny Uberoi, 212-994-8206
             suberoi@antigenics.com
             or
             Investor Relations
             Shalini Sharp, 800-962-2436
             ir@antigenics.com