Dexcom Concealed Glucose Monitor Accuracy Issues, Investor Says

Dexcom Inc. failed to inform the market of manufacturing and accuracy problems with two models of continuous glucose monitors, leading to a series of stock selloffs when adverse news emerged, an investor alleges.

Dexcom and its top executives didn’t disclose that it had made design changes without FDA approval, the Boston Retirement System says. The fund filed its proposed class action Tuesday in the US District Court for the Southern District of California.

The company didn’t disclose that the design changes made the devices less reliable, increasing risks for patients, the fund says.

Dexcom’s share price dropped 41% to close ...