Shares of EnteroMedics Inc. soared 108 percent Tuesday on positive news about the Roseville company's unique obesity-fighting medical device.

Two patient studies indicated that the company's Maestro System "shows our technology works and we're here to stay," said Chief Financial Officer Greg Lea. One of the top movers on Wall Street Tuesday, EnteroMedics' shares closed at 60 cents, up 31 cents.

EnteroMedics has developed an implanted pacemaker-like device that sends intermittent electrical impulses to the vagus nerve, which tells the brain when the stomach is empty. The technology blocks impulses that make people overeat.

The company maintains that the device is far less invasive than bariatric surgery.

The product is approved in Europe, and the company had planned to launch it in the United States next year. But last October, the company's plans were derailed when it announced that a 294-patient pivotal study failed to meet its primary endpoint, or goal.

The company's stock plummeted and has languished ever since, at least until Tuesday. It remains well short of where it stood before the setback: shares traded as high as $5.40 in September.

EnteroMedics said interim data in a 28-patient study using the second-generation device showed improved glucose and blood pressure levels in enrollees, who are obese and diagnosed with Type 2 diabetes. Weight loss was "clinically meaningful," a term that was not quantified in the company's statement.

The study, which is being conducted outside the United States, is ongoing.

In addition, updated data from the company's pivotal study in the United States continued to show a link between hours of daily device use and weight loss, said Mark Knudson, EnteroMedics' CEO.

The company will present the data at the annual meeting of the American Society of Metabolic and Bariatric Surgeons in Las Vegas Saturday.

Meanwhile, EnteroMedics continues to talk with the Food and Drug Administration about crafting a new clinical trial to gain U.S. approval of its device, Lea said. "The market really viewed this as positive information," Lea said. "We're proceeding with our plans here. We keep moving ahead for U.S. approval."

Only one analyst, William Plovanic at Canaccord Adams, follows EnteroMedics. He upgraded the stock from a hold to a buy on Tuesday.

Janet Moore • 612-673-7752