Viking Therapeutics stock jumps 36% as weight loss drug shows lasting benefits with fewer doses

Viking Therapeutics (VKTX) stock soared 35.67% on Tuesday after the company reported promising results from a study examining maintenance doses of its experimental weight loss shot, VK2735.

• When switching from weekly to every-other-week injections, patients were able to keep off up to 97% of the weight they had already lost (1).
• VK2735 is a dual GLP-1/GIP agonist, meaning the medication mimics two naturally occurring hormones to promote weight loss. While this particular version is not yet on the market, Eli Lilly's (LLY) tirzepatide is an example of a dual agonist that is currently available (1, 2).
• The study — which was randomized, double-blind, and placebo-controlled — followed 180 adults with obesity. It was split into two phases (1).
• Here are the main findings from the first phase:
  • After 21 weeks of weekly doses of VK2735, participants saw an average weight loss of 16–19%, compared to about 0% for the placebo.
  • 98% lost at least 5% of their body weight, 90% lost at least 10%, 65% lost at least 15%, and 32% lost at least 20%.
• Here are the main findings from the second phase:
  • For the next 12 weeks, participants were given maintenance doses, either every other week or once per month.
  • Those receiving VK2735 every other week were able to maintain up to 97% of the weight loss they had achieved in the first phase of the study, compared to 61% for the patients who were given a placebo.
  • Patients who received the monthly dose of VK2735 were able to keep off 90% of the weight they lost in phase one, compared to 61% on the placebo.
• Additionally, a smaller group of 13 people stayed on a higher dose of the drug for the whole study. They lost about 21.7% of their body weight, compared to a 0.3% gain for those taking the placebo. No plateau was observed.
• The company also noted that during the second phase of the study, rates of adverse events like nausea, vomiting, and gastrointestinal issues were comparable to those experienced on the placebo. During the first phase, only one person stopped taking the medication due to side effects (1).
• Viking's CEO said the results show "... the potential viability of novel, extended dosing approaches for maintenance" and that the company plans to research oral maintenance dosing in the next phase of the trial (1, 3).
• The obesity drug market is currently dominated by Eli Lilly (LLY) and Novo (NVO). Reuters noted that analysts expect the market to be worth $100B in sales by 2030 (4, 5).
• Viking believes that VK2735 could offer patients promising weight loss results with fewer injections, potentially making long-term treatment easier and differentiating the drug on the market (1).

Sources & Further Reading

1. "Viking Therapeutics Announces Positive Topline Results from Maintenance Study of GLP-1/GIP Agonist VK2735 Demonstrating the Promise of Multiple Maintenance Dosing Regimens." Viking Therapeutics. September 22, 2026.
2. "Mounjaro® (tirzepatide) Media Kit." Eli Lilly. 2026.
3. "Viking Therapeutics' obesity drug shows durable weight-loss benefit, shares jump." Reuters. September 22, 2026.
4. "Top Obesity Drugs by Revenue in 2025: The Biggest Winners in the Weight Loss Market." Delveinsight. July 10, 2026.
5. "Obesity market sales potential tightens as Novo and Lilly enter new era." Reuters. February 2, 2026.