The phase IIb study results of Supernus Pharmaceuticals Inc.’s SPN-820 in treatment-resistant depression had pulled the company’s stock (NASDAQ:SUPN) down 15.6% on Feb. 19. The randomized, double-blind, placebo-controlled study of adults failed to show a statistically significant improvement on the primary endpoint of change from baseline on the Montgomery-Åsberg Depression rating scale. Shares closed at $33.52 apiece on Feb. 19.