Nivalis Therapeutics shares tumble on negative trial results

BOULDER – Nivalis Therapeutics Inc.’s stock lost more than half of its value Tuesday after the company reported negative trial results for its cystic fibrosis drug, covosonstat.

After markets closed Monday, Boulder-based Nivalis (Nasdaq: NVLS) announced that a Phase 2 clinical trial looking at the use of cavosonstat in adult patients who also were being treated with Orkambi failed to meet its primary endpoint. Cavosonstat is the company’s lead drug candidate.

Markets reacted swiftly to the news. The company’s shares were trading at $2.56 apiece near the end of…