Xenon tumbles after Phase IIb OA miss

Xenon Pharmaceuticals Inc. (NASDAQ:XENE) fell $2 (17%) to $9.53 after its topical TV-45070 failed in a Phase IIb trial to treat chronic pain in patients with osteoarthritis of the knee. The company said 4% and 8% topical formulations of the sodium channel sub-type Nav.1.7 ( SCN9A) blocker were no more effective than placebo at reducing walking pain from baseline.

"Our best hypothesis may be insufficient drug exposure in the knee joint," Xenon President and CEO Simon Pimstone told a conference call. ...