After climbing nearly 37% since the start of the week, shares of Greenwich Lifesciences Inc. (NASDAQ:GLSI) gained another 6% on April 9 as it disclosed new data bolstering the case for its cancer immunotherapy candidate, GP2. The data, to be presented at the American Association for Cancer Research annual meeting on Saturday, showed that when HER2-positive breast cancer patients had GP2 added to standard-of-care Herceptin (trastuzumab, Roche Holding AG) following breast cancer surgery, no recurrences of their cancer were observed, even after a median follow-up of five years.