Antigenics to Report First Quarter 2009 Financial Results on May 7, 2009; Conference Call to Follow

Lexington, MA– May 4, 2009– Antigenics Inc. (NASDAQ: AGEN) will release its first quarter financial results before the market opens on May 7, 2009.

Antigenics executives will host a conference call at 11:00 a.m. Eastern Time that same day. To access the live call, dial 877.762.5772 (domestic) or 706.643.6986 (international); the access code is 96604786. 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 Eastern Time on May 21, 2009. The replay number is 800.642.1687 (domestic) or 706.645.9291 (international), and the access code is 96604786. The replay will also be available on the company's website approximately two hours after the live call.

Antigenics is a biotechnology company developing treatments for cancers and infectious diseases. For more information, please visit www.antigenics.com.