LEXINGTON, Mass., July 18, 2012 (GLOBE NEWSWIRE) -- Agenus, Inc. (Nasdaq:AGEN) today announced that GlaxoSmithKline’s (GSK) herpes zoster vaccine candidate (HZ/su), which contains Agenus’ QS-21 Stimulon®1 adjuvant as a component of GSK’s adjuvant system, has commenced a global, randomized, placebo-controlled Phase 3 clinical trial for the prevention of shingles (herpes zoster) in immunocompromised patients. This study will include approximately 200 clinical sites and enroll more than 1,400 patients 18 years of age or older undergoing hematopoietic stem cell transplantation (HCT). Herpes zoster, which can occur as a complication of HCT, has limited treatment and prevention options available.