Viking shares surge as obesity drug maintains up to 90% of weight loss with less frequent injections

Shares of U.S. biotech company Viking Therapeutics surged after its obesity treatment was shown to maintain most of its weight-loss effect even when injections were given less frequently.

According to BioPharma Dive on the 22nd (local time), Viking Therapeutics said participants in a Phase 2 trial of its dual-acting obesity drug VK2735 maintained up to 90% of their weight loss after switching from once-weekly dosing to every-other-week or monthly dosing.

Viking shares rose as much as 36% that morning in response to the news.

The company conducted the Phase 2 trial in 180 people with obesity who did not have obesity-related diseases. Participants received one of four doses of VK2735 or placebo for 21 weeks, then switched to every-other-week or monthly maintenance dosing for 12 weeks.

During the induction phase, doses were escalated to 15 mg, 17.5 mg, 20 mg or 22.5 mg once weekly. After 21 weeks, weight loss ranged from 16% in the 15-mg group to 19% in the 20-mg group.

During the maintenance phase, average weight maintenance rates ranged from 82% to 97%, depending on the dosing strategy. The rate was an average of 90% across the every-other-week groups and 85% in the monthly dosing group.

In a client note, Thomas Smith, an analyst at Leerink Research, said the data “support VK2735’s differentiated profile” and could help address some of the adherence challenges associated with obesity treatments.

Louis Aronne, a professor of metabolic research at Weill Cornell Medicine, said in a statement provided by Viking, “These results provide a basis for improving dosing flexibility for both clinicians and patients.” He added, “Flexibility is most important for achieving treatment persistence, which leads to the long-term benefits of weight management.”

Discontinuations due to adverse events were low. There was one during the induction phase, one in the every-other-week group and three in the monthly dosing group. The company said there was no “significant difference” in the frequency of gastrointestinal adverse events during the maintenance phase.

As of November 2025, enrollment in the Phase 3 trial of VK2735 was complete, and the trial is testing only once-weekly doses of up to 17.5 mg.