Key Takeaways:
Viking Therapeutics reported that patients on a 17.5 mg weekly dose of its dual GLP-1/GIP agonist VK2735 lost 22% more weight than those on placebo through Week 33, with the curve still falling at the end of the study, and the shares jumped 39% before the opening bell.
"These results are important as they provide a basis for improved dosing flexibility for both clinicians and their patients," said Louis Aronne, former president of The Obesity Society and a paid consultant to Viking.
The VK2735-102 study ran 21 weeks of weekly induction dosing in roughly 180 adults with obesity and a baseline BMI of at least 30 kg/m2, then randomized participants to 12 weeks of maintenance. Weight loss at Week 21 ranged from about 16% to 19% across the 15.0 mg, 17.5 mg, 20.0 mg and 22.5 mg cohorts, against roughly 0% for placebo (p<0.0001 for all cohorts). In the combined treatment groups, 98% of participants lost at least 5% of body weight, 90% lost 10%, 65% lost 15% and 32% lost 20%, versus 13%, 0%, 0% and 0% for placebo.
The maintenance phase is where the readout diverged from the field. Participants who moved to every-other-week dosing retained up to 97% of their Week 21 weight loss over three months, and those switched to monthly dosing retained up to 90%, compared with 61% for placebo (p<0.0001 and p=0.0002, respectively). Separation from placebo appeared as early as four weeks after the transition. An exploratory control arm that stayed on 17.5 mg weekly reached 21.7% mean weight loss from baseline at Week 33, still without a plateau.
Tolerability matched placebo during maintenance. Rates of nausea, vomiting, diarrhea and constipation were not meaningfully different from the placebo arm over the 12-week window, and discontinuations were low in both phases: one subject (1%) left the induction phase because of an adverse event, with one additional discontinuation each in the every-other-week and monthly groups. The company said the profile may support testing higher doses and exploring less frequent dosing for induction as well as maintenance.
Viking held $502 million in cash at the end of the second quarter of 2026, funding the Phase 3 obesity program and a planned Part 2 of the maintenance study that will test oral maintenance regimens. Oppenheimer kept an Outperform rating and a $100 price target into the data, arguing that investors had assumed Eli Lilly's tirzepatide would dominate the GLP-1/GIP class and that dosing frequency and adherence could reset the comparison.
The stock closed Monday at $30.11, up 3.86%, and traded at $40.97 premarket, a 35.5% gain that put it near its 52-week high of $43.15. The move was company-specific: the S&P 500 added 0.1%, the Nasdaq was flat and the Dow rose 0.3%. Short interest stood at 19.02% of float, with a $3.51 billion market cap.
For holders, the readout shifts the debate from raw weight loss to durability and convenience, the two variables that decide whether patients stay on therapy long enough to capture cardiovascular and metabolic benefit. Novo Nordisk's semaglutide and Lilly's tirzepatide both require weekly dosing, so a monthly or every-other-week maintenance option would compete on adherence rather than efficacy alone. Management hosts a conference call at 8:00 a.m. ET today, and the oral maintenance data in Part 2 is the next scheduled test of the franchise.
This article is for informational purposes only and does not constitute investment advice.
