Viking completes enrollment in second Phase 3 trial of weight-loss drug VK2735

Viking Therapeutics said on March 26, 2026 that it completed patient enrollment in VANQUISH-2, the second of its two Phase 3 trials of VK2735, an experimental once-weekly injection for obesity and type 2 diabetes ^[1].

VANQUISH-2 enrolled about 1,000 adults with type 2 diabetes who have obesity (body mass index of 30 or higher) or are overweight (BMI of 27 or higher) ^[1]. Participants were randomly assigned to one of four groups: VK2735 at 7.5 mg, 12.5 mg or 17.5 mg, or a placebo, given as a subcutaneous injection once a week for 78 weeks ^[1]. The main measure is the percent change in body weight from the start of the trial compared with placebo after 78 weeks of treatment. Researchers are also tracking how many participants lose at least 5%, 10%, 15% or 20% of their body weight ^[1]. A 52-week extension period allows participants to keep receiving treatment after the main dosing period ends ^[1].

VK2735 is a dual agonist that acts on the GLP-1 and GIP receptors, the same two receptors targeted by tirzepatide, sold as Mounjaro and Zepbound ^[1]. Semaglutide, sold as Ozempic, Wegovy and Rybelsus, targets GLP-1 alone ^[1]. Both drugs are FDA-approved in various dosage strengths and forms, and Viking is one of several companies developing additional treatments for a market now led by those two products ^[1][2].

The company reported results from a Phase 2 trial called VENTURE in 2024: after 13 weekly subcutaneous doses, participants lost up to 14.7% of their body weight on average, with no sign of a plateau, and most side effects were mild or moderate ^[1]. Treatment and study discontinuation rates in the VK2735 groups were similar to placebo, the company said ^[1]. Phase 2 results do not establish whether a drug works in a larger Phase 3 trial. Enrollment in VANQUISH-1, which tests the same drug in people who have obesity or are overweight, was completed in November 2025 ^[1]. Viking is also running a Phase 1 study of potential maintenance dosing regimens and expects to report those results in the third quarter of 2026 ^[1].

"Completing enrollment in the VANQUISH-2 study is an important milestone for Viking as it is the second of our two registration studies to be fully enrolled," chief executive Brian Lian said in a statement ^[1]. He added that the company looks forward to completing the VANQUISH studies in 2027 ^[1].

Why it matters for patients

VK2735 is not approved for any use, and finishing enrollment only means the trial has the participants it needs. The results that determine whether the drug lowers body weight, and how its side effects compare with existing options, are not in yet ^[1].

VANQUISH-2 tests the drug specifically in people with type 2 diabetes, a group that is sometimes studied separately from people without the condition ^[1]. How weight change in this group will compare with results seen in earlier trials has not been reported.

More competition among obesity drugs could eventually mean more choices for patients, but Viking has not disclosed pricing, a manufacturing plan, or an approval filing, and no trial results for the Phase 3 program have been released ^[1]. An enrollment update does not change what is known about the safety or effectiveness of the drugs already on the market.

What happens next

• Third quarter of 2026: Viking says it expects to report results from a Phase 1 study of maintenance dosing regimens for VK2735 ^[1].
• 2027: Viking says it expects to complete the VANQUISH-1 and VANQUISH-2 studies ^[1]. The company has not given a specific date for topline results from either Phase 3 trial, and no regulatory submission has been announced ^[1].