"Positive Results For Hearing Loss & Balance Disorders. The underlying adenovector delivery technology has been proven safe in thousands of patients across a range of diseases and proof of concept of TherAtoh has been established in multiple preclinical models. The program is positioned to be quickly advanced into the clinic".
source: AllPennyStocks.com Company Spotlight - GenVec Inc. (Nasdaq:GNVC)
Has / have been = present perfect