 Shares of Heat Biologics Inc. more than doubled in very active trading Tuesday, after the biopharmaceutical company focused on modulating the immune system reported positive interim data from a Phase 2 trial of its lung cancer treatment. The stock soared 115 toward a seven-month high ahead of the open on volume of 15.1 million shares, which compares with the full-day average of 1.4 million shares over the past 30 days. 