Antigenics Appoints Jill M. Forrest as Vice President of Marketing and Sales.

NEW YORK -- Antigenics Inc. (NASDAQ: AGEN) today announced that Jill M. Forrest has been appointed to the newly created position of vice president of marketing and sales. In this role, Ms. Forrest will be responsible for leading all precommercial and commercialization activities in preparation for the launch of Oncophage(R) (vitespen; formerly HSPPC-96) and other late-stage product candidates.

"With encouraging data from our Phase 3 melanoma trial of Oncophage and our plans to build a commercial cancer presence expeditiously, it's an appropriate time for us to bring in a professional of exceptional attributes," said Garo H. Armen, PhD, chairman and CEO of Antigenics. "Jill's experience in launching first-to-market oncology compounds as well as her extensive marketing and sales background in a broad range of oncology treatment settings will be invaluable to us as we prepare to build a commercial presence in oncology."

Ms. Forrest brings to Antigenics 20 years of oncology expertise, including experience in clinical trials, sales, sales training and management, marketing and global product development. She was most recently director of global marketing at Bristol-Myers Squibb Oncology, where she was responsible for the premarketing and launch efforts for the novel oncology compound vinflunine. As a senior region business director, she played a key role in the launch of Erbitux(TM) (cetuximab), a targeted biological therapy for colorectal cancer, and led national sales performance for three consecutive years. As a director of marketing, she led the launch of the chemotherapy TAXOL(R) (paclitaxel) as an adjuvant treatment in breast cancer, as well as drove marketing efforts, resulting in a 40 percent increase in breast cancer sales. Ms. Forrest received a BA in psychology from the University of Kansas.

About Antigenics

Antigenics is working to develop patient-specific immunotherapeutics and revolutionary treatments for cancers and infectious diseases. The company's lead product candidate is Oncophage, a late-stage, patient-specific cancer vaccine being evaluated in several indications, including renal cell carcinoma and metastatic melanoma. Antigenics' portfolio also includes AG-858 (HSPPC-70), a patient-specific cancer vaccine in Phase 2 development; two liposomal cancer treatments, Aroplatin(TM) and ATRA-IV; and AG-702/AG-707, a Phase 1 genital herpes program. For more information, please visit www.antigenics.com.

This press release contains forward-looking statements, including statements regarding the benefits of Ms. Forrest joining Antigenics, the expected launch of Oncophage and other product candidates, and plans to build a commercial presence. These statements are subject to risks and uncertainties that could cause actual results to differ materially from those projected in these forward-looking statements. Risks and uncertainties include, among others, that clinical trails fail to demonstrate, in a statistically significant manner, that Oncophage and other product candidates are as safe and more effective than alternative treatments; that Antigenics fails to obtain marketing approval from the FDA or fails to do so without extended delays; decisions by regulatory agencies, including the FDA, regarding interpretation of clinical trial data and demands for additional clinical trials; 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 10, 2005. 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. 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. The prior track record of Ms. Forrest does not assure Antigenics' future success.