Viking completes enrollment in the Phase 3 VANQUISH-2 trial

Viking Therapeutics said on March 26, 2026, that it has completed enrollment in VANQUISH-2, the second of two Phase 3 trials testing its injectable drug VK2735 in adults with type 2 diabetes who also have obesity or are overweight.^[1] The company had already finished enrolling its other pivotal study, VANQUISH-1, in patients with obesity or who are overweight but without diabetes, in November 2025.^[1] With both trials now fully enrolled, Viking has cleared a key step toward asking regulators to approve VK2735 as a new weight-loss treatment.

VANQUISH-2 enrolled roughly 1,000 adults with a body mass index of 30 or higher, or 27 or higher with an existing weight-related condition, all of whom also have type 2 diabetes.^[1] Participants were randomly assigned to one of four weekly injection groups: VK2735 at 7.5 mg, 12.5 mg, or 17.5 mg, or a placebo.^[1] The trial runs 78 weeks and measures how much body weight changes compared with placebo, plus how many people lose at least 5%, 10%, 15%, or 20% of their starting weight.^[1] A 52-week extension will let participants keep taking the drug after the main study ends.^[1]

VK2735 works by activating both the GLP-1 and GIP hormone receptors, the same dual mechanism used by tirzepatide, sold as Mounjaro and Zepbound.^[1] In an earlier Phase 2 study called VENTURE, published in 2024, people taking VK2735 for 13 weekly doses lost up to 14.7% of their body weight on average, with weight loss still trending downward and no plateau reached.^[1] Most side effects in that trial were mild or moderate, and the rate of people quitting the study was similar between drug and placebo groups.^[1] Viking's chief executive, Brian Lian, said the speed of enrollment in both VANQUISH trials reflects strong interest in obesity treatments beyond what is currently on the market, and the company expects to complete both studies in 2027.^[1]

Viking is also running a separate Phase 1 study looking at different maintenance dosing schedules for VK2735, with results expected in the third quarter of 2026.^[1] The company is developing an oral version of VK2735 as well.^[1]

Why it matters for patients

VK2735 is not yet approved and is still years away from reaching pharmacies, so it offers no immediate treatment option. But its progress matters because it represents one of the more advanced efforts by a company outside Novo Nordisk and Eli Lilly to build a competing GLP-1/GIP drug. More competitors reaching late-stage trials could eventually mean more choices and, potentially, downward pressure on prices if a product is approved.

The drug landscape it would enter is already crowded. As of mid-2026, four obesity drugs are FDA approved, including Wegovy in both injectable and pill form, Zepbound, and Foundayo, an oral GLP-1 drug from Eli Lilly approved in April 2026.^[2] Novo Nordisk's CagriSema has an FDA decision expected around the end of 2026, though a head-to-head trial found it did not match tirzepatide's weight-loss results.^[2] Eli Lilly's retatrutide, tested in a large Phase 3 trial, showed 28.3% average weight loss at 80 weeks in results reported in May 2026, though it has not yet been filed for approval.^[2] VK2735's future competitiveness will depend on how its Phase 3 results, expected in 2027, compare with these rivals.

What happens next

Viking expects results from its Phase 1 maintenance dosing study in the third quarter of 2026.^[1] The company has said it aims to complete both VANQUISH-1 and VANQUISH-2 in 2027, which would set up the data needed to seek FDA approval.^[1] No specific readout date or filing date has been announced.