In the following video, Motley Fool health-care analyst David Williamson takes a look at the dizzying ups and downs of Peregrine Pharmaceuticals (NASDAQ:PPHM). The ongoing saga with the company's leading candidate cancer drug bavituximab has seen shares soar 80% in January, plummet 39% in February, and rally again this month, leaving the stock up 20% overall for the year. David gives investors his take on the drug and where he thinks this wild ride is finally going to end up.