Ampio Pharmaceuticals (AMPE) shares have tumbled in trading today after the company announced that a Phase 3 clinical trial, PIVOT, assessing Ampion, an intra-articular injection for the potential treatment of pain associated with osteoarthritis (OA) of the knee, failed to beat placebo (saline injection). Ampion also failed a Phase 3 study in OA of the knee in 2015. The company says it will meet with the FDA to discuss all of its data.