It's been more than six years since 2007 start-up Vaccinogen Inc. licensed rights to Oncovax, a cancer vaccine set to start a confirmatory phase III study in colon cancer. During that time, the immunotherapy space saw more than its share of highs and lows – the excitement surrounding the approval of Dendreon Corp.'s prostate cancer vaccine Provenge (sipuleucel-T) subsequently crushed by discouraging sales, followed by immunotherapy wins with Bristol-Myers Squibb Co.'s Yervoy (ipilimumab) and the new PD-1 checkpoint inhibitors.