Viking Therapeutics (NASDAQ: VKTX) announced on October 6, 2026 that it has started Part 2 of an exploratory maintenance-dosing study for VK2735, its dual GLP-1/GIP receptor agonist, aiming to test whether patients can hold onto weight lost during an initial treatment period using less-frequent or oral dosing regimens.
What the Study Is Testing
The study is a randomized, double-blind, placebo-controlled trial enrolling approximately 195 adults with obesity, defined as a body mass index of 30 kg/m² or higher. In the induction phase, participants receive either weekly subcutaneous (injected) VK2735 or placebo for 21 weeks. At that point, the trial moves into its maintenance phase: participants are re-randomized into one of several different regimens, including a daily oral pill, a weekly oral pill, a monthly subcutaneous injection, an every-other-week subcutaneous injection, or placebo, which they'll stay on through week 33. The company's primary goal for this phase is gathering safety, tolerability, and pharmacokinetic (how the drug moves through and is cleared from the body) data across all of those different regimens and schedules. Exploratory endpoints will track how body weight changes both from the start of the study and from week 21, when the maintenance phase begins.
Why a Maintenance Study Matters
Most of the headline data for GLP-1 and dual-agonist drugs, including VK2735's own earlier results, comes from induction-phase trials measuring how much weight participants lose during active, typically weekly, injection treatment. A maintenance study asks a different and arguably more practical question: once a patient has lost a meaningful amount of weight, what's the least burdensome regimen that can keep it off? That's directly relevant to one of the most common real-world problems with GLP-1-class drugs, discussed elsewhere on this site: a substantial share of patients who stop these medications regain some or all of the weight they lost. A regimen that maintains results with a monthly injection or a daily pill, rather than a weekly shot, could meaningfully change how sustainable long-term treatment is for patients.
How This Fits With VK2735's Broader Program
This maintenance study is separate from Part 1, which began in 2025, tested only subcutaneous dosing schedules, and recently reported positive topline results, according to Viking's announcement. It's also distinct from VK2735's two ongoing Phase 3 trials, VANQUISH-1 and VANQUISH-2, which are testing weekly subcutaneous VK2735 over 78 weeks and are both fully enrolled. Those larger trials remain the primary pathway toward a potential FDA approval decision; this smaller, exploratory maintenance study is aimed at answering dosing and convenience questions that would matter after an approval, not at generating the core efficacy data regulators would evaluate first. Results from this Part 2 maintenance study are expected in 2027.
Regulatory and Evidence Status
VK2735 is not FDA-approved for any use. It remains an investigational drug, and like all of Viking's ongoing trials, this study is being conducted under an active Investigational New Drug application with FDA oversight of patient safety. No outcome from this maintenance study, however it turns out, will itself constitute an approval or change VK2735's current regulatory status. As with other dual and triple agonists in development, discussed in this site's broader coverage of the late-stage peptide pipeline, efficacy and long-term safety data are still being generated in controlled trials rather than established through real-world use.
The Bottom Line
Viking has moved into the next stage of a practical question that matters as much as initial weight loss: whether patients can maintain results on a less demanding schedule, potentially including a pill instead of a weekly injection. The trial's safety and pharmacokinetic data, expected in 2027, will be an early signal of whether oral or infrequent dosing for VK2735 is a realistic path forward, well before any decision about its approval for weight management.