Altimmune Inc. jumped as much as 66% in late trading after the biotech company reported results from a mid-stage study of its experimental weight-loss drug, pemvidutide.

In a 48-week trial, the highest dose of the drug helped patients lose up to 16% of their body weight, or 32.2 pounds, the company said Thursday. Those results put it on par with Novo Nordisk A/S’s blockbuster weight loss drug Wegovy, which helped patients achieve 15% weight loss in a 68-week trial.

Altimmune shares were up 30% to $4.12 at 5:48 p.m. in extended New York trading, paring some of an earlier gain. As of Thursday’s close, the Gaithersburg, Maryland-based company’s market capitalization was almost $170 million.

Companies are racing to replicate the success of highly popular drugs made by Novo and rival Eli Lilly & Co. that are being used for weight loss and generating enormous sales. Some drugmakers are advancing their own products into clinical trials, while others are looking into acquiring smaller companies that have produced promising results.

Patients in the Altimmune trial continued losing weight at the end of treatment and saw reductions in blood pressure without meaningful increases in heart rate that have been observed with some other weight loss drugs, the company said. Almost a third of trial participants achieved 20% or more weight loss on the highest 2.4 milligram dose.

The most common side effects were nausea and vomiting, and only one patient experienced what was considered a serious complication.

“The level of weight loss achieved at 48 weeks in this trial has been shown to reverse the key complications of obesity,” Chief Medical Officer Scott Harris said in the statement. The company is developing the drug for obesity and a severe form of liver disease.

Altimmune management will hold a conference call Friday morning to discuss the results.