$Xenon Pharmaceuticals(XENE)$ Thinly traded micro cap Xenon Pharmaceuticals (NASDAQ:XENE) drops 22% premarket on increased volume in response to its announcement that a Phase 2b trial run by development partner Teva Pharmaceutical Industries (NYSE:TEVA) evaluating TV-45070 (formerly XEN402) in patients with pain due to osteoarthritis of the knee failed to demonstrate a statistically significant difference from placebo