Antigenics Reports Fourth Quarter and Year-End 2005 Financial Results and Highlights

Antigenics Inc. (NASDAQ: AGEN) today reported financialresults and operating highlights for the quarter and year endedDecember 31, 2005. For the three months ended December 31, 2005, thecompany incurred a net loss attributable to common stockholders of$17.9 million, or $0.39 per share, basic and diluted, compared with anet loss attributable to common stockholders of $17.6 million, or$0.39 per share, basic and diluted, for the same period in 2004. Forthe year ended December 31, 2005, Antigenics incurred a net lossattributable to common stockholders of $74.9 million, or $1.64 pershare, basic and diluted, compared with a net loss attributable tocommon stockholders of $57.0 million, or $1.27 per share, basic anddiluted, for the same period in 2004. The increase in net loss fromcontinuing operations reflects the costs to advance development of thecompany's product candidates, including Oncophage(R) (vitespen;formerly HSPPC-96), Antigenics' lead product candidate, as well ascosts associated with other clinical and development projects. Theincrease in net loss attributable to common stockholders compared withthat in 2004 is primarily attributable to the gain on the sale toVirbac S.A. during 2004, of our manufacturing rights for felineleukemia vaccine, as well as increased research and developmentexpenses associated with our clinical programs during 2005. Cash, cashequivalents and short-term investments amounted to $61.7 million onDecember 31, 2005.

"In 2005, we generated our first randomized Phase 3 data withOncophage, which showed that a prospectively defined group ofbetter-prognosis stage IV melanoma patients who received Oncophageappeared to be living much longer than similar patients who did notreceive the vaccine," said Garo H. Armen, PhD, chairman and CEO ofAntigenics. "With data from our Phase 3 kidney cancer trial beinganalyzed in the coming weeks, we hope to further demonstrate theclinical activity of Oncophage. Our other vital development programs,including Aroplatin(TM), AG-707 and our QS-21 adjuvant, continue toprogress, positioning Antigenics as a company with a diversifiedpipeline offering multiple sources of potential revenue."

Corporate Highlights

-- A Phase 3 trial testing Oncophage, a patient-specific therapeutic cancer vaccine, in adjuvant renal cell carcinoma (RCC; the most common form of kidney cancer) is on track for data analysis in March 2006, with top-line data available shortly thereafter.

-- Antigenics anticipates publishing final data from a Phase 3 trial testing Oncophage in metastatic melanoma in a peer-reviewed journal and presenting it at an upcoming medical conference. Preliminary data showed a greater than 50-percent improvement (not statistically significant) in median survival on an intent-to-treat basis in stage IV M1a patients in the Oncophage-treated arm compared with those in the physician's choice arm (20.9 months versus 12.8 months).

-- The company continues to pursue Phase 1/2 trials evaluating Oncophage in combination with chemotherapeutic or biological agents, with the goal of generating information related to safety and tumor response in cancer patients with more advanced disease. The first US investigational new drug (IND) application for the study of Oncophage in combination with ATRA-IV in a Phase 1 trial in patients with metastatic RCC and melanoma has been approved.

-- An investigator-sponsored Phase 1/2 study of Oncophage as a treatment for recurrent glioma is being conducted at the Brain Tumor Research Center at the University of California, San Francisco. The first patient has been enrolled.

-- A multicenter Phase 1 clinical trial has been initiated with Aroplatin, a liposomal formulation of a proprietary platinum chemotherapeutic. This dose-ranging study involves patients with advanced solid malignancies or B-cell lymphoma, and will evaluate the safety and pharmacokinetic profile of Aroplatin, which has been reformulated to enhance the drug's activation and stability.

-- AG-707, a therapeutic vaccine for genital herpes, is under investigation in a Phase 1 multicenter clinical trial evaluating the safety of and immune response to AG-707 in patients infected with herpes simplex virus type 2, the primary cause of genital herpes.

-- An expanded exploratory Phase 2 clinical study is underway with AG-858, a patient-specific therapeutic cancer vaccine, in combination with Gleevec(R) (imatinib mesylate, Novartis) for the treatment of chronic myelogenous leukemia patients refractory to Gleevec. The trial will assess extended dosing of AG-858.

-- The company continues to advance important preclinical programs, such as AU-801 for the treatment of autoimmune diseases and higher-activity Oncophage made through an improved process.

-- A number of Antigenics' partners' products containing our QS-21 adjuvant have advanced in the clinic. The company estimates that as many as five products containing QS-21 have significant commercial potential and may enter the market over the next several years, potentially generating significant royalty income for Antigenics.

-- Antigenics is operating with a streamlined organization following the December 2005 reevaluation of its preclinical and clinical development programs, which resulted in headcount reductions across functions and significant cost savings in future periods. The company has also strategically invested in key hires, including Bruce A. Leicher as vice president and general counsel and Jill M. Forrest as vice president of marketing and sales.

Conference Call Information

Antigenics executives will host a conference call at 11:00 a.m. ETtoday. To access the live call, dial 888.271.9082 (domestic) or706.679.7741 (international); the access code is 5442896. The callwill also be webcast and will be accessible from the company's websiteat www.antigenics.com/webcast/. A replay will be availableapproximately two hours after the call through midnight ET on March 9,2006. The replay number is 800.642.1687 (domestic) or 706.645.9291(international), and the access code is 5442896. The replay will alsobe available on the company's website approximately two hours afterthe live call.

About Antigenics

Antigenics is a biotechnology company working to developpatient-specific immunotherapeutics and revolutionary treatments forcancers, infectious diseases and autoimmune disorders. The company'slead product candidate is Oncophage (vitespen; formerly HSPPC-96), alate-stage, patient-specific cancer vaccine being evaluated in severalindications, including renal cell carcinoma and metastatic melanoma.Antigenics' portfolio of investigational products also includes AG-858(HSPPC-70), a patient-specific cancer vaccine in Phase 2 development;two liposomal cancer treatments, Aroplatin and ATRA-IV; AG-707, aPhase 1 genital herpes vaccine; and QS-21, an immune adjuvant. Formore information, please visit www.antigenics.com.

This press release contains forward-looking statements, includingstatements regarding the further demonstration of clinical activity ofOncophage, the revenue-generating potential of the product pipeline,the timing of analysis and announcement of data from the Phase 3 trialin RCC, timing of and plans to publish and present data from the Phase3 trial in melanoma, plans to commence new clinical trials, plans togenerate information related to the safety, efficacy,pharmacokinetics, dosing and immune response generation of productcandidates, plans to advance preclinical programs and the commercialpotential and market entry of products containing QS-21 as well asassociated royalty income for Antigenics. These forward-lookingstatements are subject to risks and uncertainties that could causeactual results to differ materially. These risks and uncertaintiesinclude, among others, timing of events in the RCC trial, the resultsof clinical trials, the cost of additional clinical trials, theability to raise additional capital, and the factors described underFactors That May Impact Future Results in the Management's Discussionand Analysis of Financial Condition and Results of Operations sectionof Antigenics' Form 10-Q as filed with the Securities and ExchangeCommission on November 4, 2005. Antigenics cautions investors not toplace considerable reliance on the forward-looking statementscontained in this press release. These statements speak only as of thedate of this document, and Antigenics undertakes no obligation toupdate or revise the statements. All forward-looking statements areexpressly qualified in their entirety by this cautionary statement.Antigenics' business is subject to substantial risks anduncertainties, including those identified above. When evaluatingAntigenics' business and securities, investors should give carefulconsideration to these risks and uncertainties.

Summary Consolidated Financial Information

Condensed Consolidated Statements of Operations Data
(in thousands, except per share data)
(unaudited)


Three months ended Year ended
December 31, December 31,
2005 2004 2005 2004
--------- --------- --------- ---------


Revenue $ 348 $ 128 $ 630 $ 707

Operating expenses:
Cost of sales - - - 5
Research and development 10,689 10,077 47,080 41,718
General and administrative 6,361 7,345 25,869 25,784
Severance costs 990 - 1,596 -
Acquired in-process research
and development - - - 2,888
-------- -------- -------- --------
Operating loss (17,692) (17,294) (73,915) (69,688)

Other (expense) income, net (26) 290 (189) 937

--------- --------- --------- ---------
Loss from continuing operations (17,718) (17,004) (74,104) (68,751)

Income (loss) from
discontinued operations, net
of tax (including gain on
disposal of $14,000 in 2004) - (445) - 12,589

--------- --------- --------- ---------
Net loss (17,718) (17,449) (74,104) (56,162)

Dividends on Series A
convertible preferred stock (198) (197) (791) (790)

Net loss attributable to common -------- --------- --------- ---------
stockholders $(17,916) $(17,646) $(74,895) $(56,952)
======== ======== ======== ========

Per common share data:
Loss from continuing
operations, basic and diluted$ (0.39) $ (0.38) $ (1.64) $ (1.56)
Net loss attributable to
common stockholders, basic
and diluted $ (0.39) $ (0.39) $ (1.64) $ (1.27)
Weighted average number of
common shares outstanding,
basic and diluted 45,591 45,518 45,577 44,685



Condensed Consolidated Balance Sheet Data
(in thousands)
(unaudited)

December 31, December 31,
2005 2004
----------- -------------

Cash, cash equivalents and
short-term investments $ 61,748 $ 86,921
Total assets 104,151 133,058
Total stockholders' equity 31,899 106,443