When Insys Therapeutics ($INSY) won approval for its new narcotic painkiller, Subsys, in 2012, few predicted the product would find much of a market, because the FDA limited its use to cancer patients who were already on powerful painkillers. But in 2013, the product raked in $96 million in sales, and the company's stock price quintupled to $25 a share. According to The New York Times, off-label marketing may have helped. Report | Article (sub. req.)