San Diego, California, United States, October 14, 2026
Viking Therapeutics, Inc. has initiated its Phase 3 clinical development program for oral VK2735, an investigational medication being developed for the treatment of obesity and weight management. Announced on October 14, 2026, the program includes two pivotal studies, SUNRISE-1 and SUNRISE-2, designed to evaluate the safety and efficacy of a once-daily oral formulation of VK2735 in adults with obesity, including people living with type 2 diabetes. VK2735 is a dual agonist of the glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors, two targets involved in appetite regulation, glucose metabolism, and body-weight control. The advancement into Phase 3 represents a major milestone for Viking’s obesity treatment pipeline, following encouraging results from its earlier Phase 2 VENTURE-Oral Dosing study. The company is developing VK2735 in both oral tablet and subcutaneous injectable formulations, with the goal of potentially offering different treatment options for patients and healthcare professionals. The oral Phase 3 program will assess whether the earlier weight-loss findings can be confirmed in larger patient populations over a longer treatment period. VK2735 remains investigational and has not been approved for the treatment of obesity.
SUNRISE-1 and SUNRISE-2 Evaluate Oral VK2735
The Phase 3 SUNRISE clinical program consists of two randomized, double-blind, placebo-controlled, multicenter trials, each targeting enrollment of approximately 560 adults. SUNRISE-1 will evaluate oral VK2735 in adults with obesity, defined as a body mass index (BMI) of at least 30 kg/m², or adults who are overweight, with a BMI of at least 27 kg/m², and have at least one weight-related comorbidity. Participants in this study will not have type 2 diabetes. SUNRISE-2 will assess the investigational treatment in adults with type 2 diabetes who have obesity or are overweight. In both studies, participants will receive once-daily oral VK2735 at doses of 27.5 mg, 35 mg, or 55 mg, or a matching placebo. Treatment is planned for 68 weeks, allowing researchers to evaluate weight changes over an extended period. The primary endpoint for both trials is the percentage change in body weight from baseline at Week 68 compared with placebo. Secondary and exploratory endpoints will examine the proportions of participants achieving weight reductions of at least 5%, 10%, 15%, and 20%, alongside additional safety and efficacy measures. The trial design will help researchers assess whether oral VK2735 can provide sustained weight reduction in different patient populations and characterize its tolerability during longer-term treatment.
Earlier Phase 2 Results Support Clinical Advancement
The initiation of Phase 3 follows positive top-line findings from Viking’s Phase 2 VENTURE-Oral Dosing study, which evaluated once-daily oral VK2735 in adults with obesity. After 13 weeks of treatment, participants receiving VK2735 experienced statistically significant, dose-dependent reductions in mean body weight, reaching up to 12.2% from baseline, compared with approximately 1.3% in the placebo group. The company also reported that weight loss continued progressively throughout the study, without an observed plateau during the treatment period. Across the active-treatment groups, up to 97% of participants achieved at least 5% weight loss, while up to 80% achieved at least 10% weight loss. These results supported the decision to evaluate the oral formulation in larger, longer-duration studies. The Phase 2 study also provided initial safety and tolerability information. According to Viking, 98% of reported drug-related treatment-emergent adverse events were classified as mild or moderate. Gastrointestinal events were the most commonly reported adverse events, consistent with the known effects of GLP-1/GIP receptor agonists. Such events generally occurred early in treatment and tended to subside with continued dosing. However, results from a relatively short Phase 2 study cannot establish long-term safety or predict the final outcomes of Phase 3 trials. The larger studies will provide additional evidence on efficacy, tolerability, and treatment consistency.
Advertisement
Oral and Injectable Formulations Expand Development Strategy
Viking is advancing VK2735 through a broader development strategy that includes both oral and injectable approaches to obesity management. The company is already conducting the Phase 3 VANQUISH-1 and VANQUISH-2 trials, which evaluate once-weekly subcutaneous VK2735 over 78 weeks. VANQUISH-1 focuses on adults with obesity or overweight and weight-related comorbidities who do not have type 2 diabetes, while VANQUISH-2 includes adults with type 2 diabetes who are overweight or have obesity. Viking has also initiated a separate maintenance-dosing study to explore different oral and injectable regimens following initial weight loss. These programs reflect the company’s interest in evaluating treatment options that could address both initial weight reduction and longer-term weight maintenance. An effective oral formulation could offer an alternative for patients who prefer tablets to injections, although convenience, adherence, safety, and clinical effectiveness must be established through research. The SUNRISE trials will be important in determining whether VK2735 can demonstrate sustained benefits in a broader clinical setting. Their results will also help clarify the potential role of oral dual GLP-1/GIP receptor agonism in obesity treatment. Until the clinical program is completed and regulatory review occurs, VK2735 remains an investigational therapy rather than an approved treatment.
Source: Viking Therapeutics press release
