Viking Therapeutics starts a VK2735 maintenance and reduced-frequency dosing study

Viking Therapeutics began a Phase 1 study in October 2025 to test whether patients can maintain weight loss on VK2735 using less frequent dosing, such as every other week or once monthly, instead of the standard weekly injection ^[1]. The company describes it as a dose-ranging study meant to explore the feasibility of these alternate maintenance schedules ^[1]. As of the company's most recent update, results were expected in the third quarter of 2026 ^[1].

VK2735 is Viking's injectable drug that acts on both the GLP-1 and GIP receptors, similar in mechanism to tirzepatide ^[1]. In an earlier Phase 2 study called VENTURE, people taking weekly VK2735 lost up to 14.7% of their body weight after 13 weeks, with no sign of the weight loss leveling off, and the drug was generally well tolerated ^[1]. Those results led Viking to move into two large Phase 3 trials, VANQUISH-1 and VANQUISH-2, testing weekly injections at 7.5 mg, 12.5 mg, or 17.5 mg for 78 weeks in people with obesity, including some with type 2 diabetes ^[1]. VANQUISH-1 enrolled about 4,500 people by November 2025, and VANQUISH-2 finished enrolling about 1,000 people in the first quarter of 2026 ^[1].

The maintenance study is separate from those late-stage trials and focuses specifically on what happens after initial weight loss is achieved. Viking says the goal is to see whether spacing out doses can help people hold onto the weight they've already lost, rather than testing the drug for initial weight loss itself ^[1]. Company CEO Brian Lian said in July 2026 that the maintenance study "continued to progress" and that Viking expected to report results "later this quarter," referring to the third quarter of 2026 ^[1]. Viking has framed reduced-frequency dosing as a potential way to make long-term treatment easier to stick with, since it says flexible dosing options may improve how long patients stay on therapy once they've reached their goals ^[1].

Why it matters for patients

Most approved GLP-1 and GIP drugs, including Ozempic, Wegovy, and Zepbound, are given as weekly injections indefinitely, and studies have shown weight often returns if people stop treatment. A drug that can be spaced out to every other week or once a month, if it works, could mean fewer injections and possibly lower ongoing costs or hassle for people trying to maintain weight loss over years. But this is an early, Phase 1 feasibility study, not a large trial proving the approach works or is safe at reduced frequency ^[1]. It is not yet known whether less frequent dosing would maintain weight loss as effectively as staying on a weekly schedule, or how side effects might differ. No results have been reported yet, so any potential benefit remains unproven.

It's also worth noting that VK2735 itself is not an approved drug. It is still in Phase 3 testing for the standard weekly regimen, with the VANQUISH trials running through 2026 and beyond ^[1]. Viking is also developing an oral tablet version of VK2735, which showed weight loss of up to 12.2% after 13 weeks in an earlier study, with Phase 3 trials for the tablet expected to start in the fourth quarter of 2026 ^[1]. The company has suggested that patients might eventually be able to switch between the injectable and oral forms of VK2735 since they share the same active ingredient, though this idea has not yet been tested in large trials ^[1].

What happens next

Viking expects to report maintenance dosing study results in the third quarter of 2026 ^[1]. The company's oral VK2735 Phase 3 trial was expected to begin in the fourth quarter of 2026 ^[1]. The VANQUISH-1 and VANQUISH-2 Phase 3 trials for weekly injectable VK2735 were continuing as of Viking's July 2026 update, with the primary endpoint measuring weight change after 78 weeks of treatment ^[1]. VK2735 remains investigational and has not been approved by the FDA for any use.