VK2735: Viking Starts Its Oral Phase 3 Trials and Reports Less-Frequent Maintenance Dosing
Published: November 3, 2026 · 3 min read · By Grey Peptides News Desk · ✓ Sourced
Viking Therapeutics says SUNRISE-1 and SUNRISE-2, the phase 3 trials of its once-daily VK2735 tablet for weight management, began in October 2026. It also reports that after 21 weeks of weekly injections, people moved to monthly or every-other-week doses kept most of the weight they had lost. Both are the company's statements; VK2735 is not approved anywhere, and none of these results has been peer reviewed.
The oral phase 3 trials
VK2735 is a dual agonist of the GLP-1 and GIP receptors, the same pair tirzepatide acts on, that Viking is developing both as a weekly injection and as a daily tablet. In its October 28 update the company said SUNRISE-1 and SUNRISE-2 were initiated in October. Each is planned for about 560 adults, randomised to 27.5 mg, 35 mg or 55 mg of oral VK2735 once a day, or placebo, for 68 weeks. SUNRISE 1's registration on ClinicalTrials.gov gives the primary outcome as the percentage change in body weight at week 68, in people without type 2 diabetes. The registry, last updated October 16, still lists the trial as not yet recruiting with a November start, so it and the company's statement differ on timing.
The maintenance study
Viking first reported this study on September 22. About 180 adults with obesity took weekly VK2735 injections for 21 weeks, then switched to lower or less frequent doses, or placebo, for 12 more weeks. The company reports:
- After 21 weeks of weekly doses: weight fell about 16% to 19% depending on dose, against about 0% on placebo; 90% of treated people lost at least 10% and 32% at least 20%.
- Monthly maintenance: people kept 82% to 90% of the weight they had lost by week 21, at week 33.
- Every-other-week maintenance: 83% to 97% kept.
- Switched to placebo: 61% kept.
- Kept on weekly 17.5 mg: about 22% lower than baseline at week 33, a small exploratory group of 13.
Viking says side effects during maintenance were similar to placebo, with few digestive events.
What it means for readers
The maintenance question matters because, in this same study, people switched to placebo regained about two-fifths of the weight they had lost within 12 weeks. A monthly dose that holds most of the loss would make long-term use simpler. But the groups were small, ten to sixteen people per maintenance arm, and the maintenance period was only 12 weeks.
What is not yet known
None of these results is published. The injection's own phase 3 trials, VANQUISH-1 and VANQUISH-2, with about 4,500 and 1,000 people enrolled, are expected to finish in 2027, and a second part of the maintenance study is due to report in 2027. Viking has announced no regulatory filing. VK2735 is not approved anywhere.
Related on Grey Peptides
The VENTURE trials, the phase 3 programme and its regulatory status. Tirzepatide encyclopedia entry
The approved drug that acts on the same two receptors. Peptide pipeline tracker
VK2735's row, with its next milestone.
ClinicalTrials.gov - Oral VK2735 for Weight Management Phase 3 (SUNRISE 1, NCT07868835)
Trial design read on ClinicalTrials.gov on November 3, 2026. The trial start and the maintenance results are Viking Therapeutics' own, from its October 28, 2026 quarterly update (filed with the SEC) and its September 22, 2026 announcement, both read in full on November 3; none of it is published in a journal.