Dr Pepper’s 10-calorie soft drink may debut across the United States by the end of the year due to blockbuster reception in six test cities, the head of Dr Pepper Snapple Group said Monday.

“It’s just blowing our projections away,” Chief Executive Larry Young told the Reuters Global Food & Agriculture Summit. Sales to repeat customers are “stronger than Dr Pepper Cherry when we launched it.”

The nation’s third-largest soft drink maker, which owns 7UP, Canada Dry and Mott’s, makes Dr Pepper 10 with a proprietary sweetener blend.

“It has the taste of old Dr Pepper with sugar in it, with only 10 calories,” Young said Monday at the summit, held at the Reuters office in Chicago.

Strong demand from Kansas City, San Antonio and four other cities could lead to a nationwide rollout by the fourth quarter, depending on additional marketing data, he said.

“I’m hoping we’re bringing people back that have left the Dr Pepper brand,” Young said.

Dr Pepper Snapple’s business is concentrated in North America, in contrast to its bigger rivals Coca-Cola Co. and PepsiCo Inc.