Viking Therapeutics has released Phase 2 trial results for its oral obesity drug candidate, VK2735. The study showed placebo-adjusted weight loss of up to 12.2% at 13 weeks, sparking comparisons with industry leaders Novo Nordisk and Eli Lilly.
Viking’s Phase 2 Results for VK2735
The randomized, placebo-controlled Phase 2 study evaluated multiple doses of oral VK2735 in 280 adults with obesity. Results showed:
- Placebo group: 1.3% weight loss after 13 weeks.
- VK2735 groups: Ranged from 2.3% to 12.2% weight loss after 13 weeks.
- Extension: Additional weight loss was observed at 16 weeks, suggesting continued efficacy with longer dosing.
How VK2735 Compares to Novo Nordisk and Eli Lilly
Viking’s results are being compared to other oral GLP-1 receptor agonists:
- Novo Nordisk: Oral semaglutide showed 15.1% weight loss after 68 weeks at higher doses.
- Eli Lilly: Reported 12.4% weight loss after 72 weeks with its obesity therapy.
On a placebo-adjusted basis at 13 weeks, VK2735 outperformed early-stage results from both companies:
- Viking: 10–11% weight loss
- Lilly: ~6% weight loss
- Novo (high-dose oral semaglutide): ~4% weight loss
Key Concern: Discontinuation Rates and Tolerability
While efficacy is strong, tolerability issues cloud commercial prospects:
- Discontinuation rates:
- 20% at 15 mg
- 22% at 30 mg
- 38% at 90 mg (highest dose)
- Most common side effect: Nausea, leading to treatment discontinuation.
Lian suggested that slower dose titration could improve tolerability. Analysts also noted that GI side effects (nausea, vomiting) were also reported in placebo groups, reflecting patient sensitivity due to prior GLP-1 exposure.
Commercial Viability of VK2735 Doses
Analysts are questioning which dose Viking will advance into pivotal trials:
- 30 mg dose: Considered commercially viable and potentially usable as a maintenance dose.
- Higher doses (90–120 mg): Less likely to move forward due to tolerability concerns.
- Taper strategy: A 90 mg loading dose followed by taper to 30 mg showed continued weight loss of 9.2% at 13 weeks, suggesting a feasible balance between efficacy and tolerability.
William Blair analysts stated they do not expect Viking to pursue 90 mg or 120 mg doses but believe dose titration strategies could enhance tolerability at lower doses.
Outlook for Viking’s Obesity Drug Program
Despite the stock decline, VK2735 data positions Viking as a serious competitor to Novo Nordisk’s Wegovy and Eli Lilly’s Zepbound in the growing anti-obesity drug market.
- Efficacy: Outpaces early trial results from major competitors.
- Challenges: Dose discontinuation and GI side effects need to be addressed.
- Commercial potential: A 30 mg maintenance dose could offer both clinical effectiveness and scalability.
As obesity drug demand surges globally, Viking’s Phase 2 results underline the company’s potential, but investors remain cautious until dosing and tolerability strategies are clarified.
