** Biotechnology company's shares up 12 pct at$3.75 premarket
** Says shingles vaccine developed by partnerGlaxoSmithKline Plc met main goal in a late-stage study
** The vaccine, HZ/su, combines protein found on virus thatcauses shingles with a component from Agenus
** Agenus to get royalties on potential commercial sales ofHZ/su
** Up to Wednesday's close, stock had risen 8 pct this year