ECO2026 Recap — Oral GLP-1 Data from Novo, Lilly, and Viking

The European Congress on Obesity (ECO2026) ran May 12-15, 2026, in Istanbul, Türkiye. Three companies — Novo Nordisk, Eli Lilly, and Viking Therapeutics — presented new data on oral GLP-1 receptor agonists, advancing what has historically been an injectable-dominated category. Here’s a breakdown of what each company showed and how the data fits into the broader landscape.

Novo Nordisk — Wegovy Pill (Oral Semaglutide 25mg)

Novo Nordisk presented sub-analyses from its Phase 3 OASIS 4 trial on May 13. The headline finding centered on early responders — patients who achieved at least 10% weight loss by week 16 of treatment.

Key results:

• 28.8% of patients met the early responder criteria
• Early responders had achieved 13.2% weight loss by week 16
• By week 64 (end of trial), early responders achieved 21.6% weight loss
• Non-early-responders still achieved 11.5% weight loss at week 64

Novo also presented two additional studies:

ORION — an indirect treatment comparison study comparing Wegovy pill to Eli Lilly’s orforglipron (brand name Foundayo). Per Novo, Wegovy pill demonstrated greater weight loss and lower odds of treatment discontinuation due to side effects. Indirect comparisons carry methodological limitations relative to head-to-head trials, but the data provides a useful early benchmark while a true head-to-head study remains absent from the category.

OPTIC — a late-breaking patient preference study examining what patients value in obesity medications.

Wegovy pill is currently the only FDA-approved oral GLP-1 receptor agonist for weight management.

Eli Lilly — ATTAIN-MAINTAIN and SURMOUNT-MAINTAIN

Lilly’s ECO2026 presentations focused on a different clinical question: can oral GLP-1 drugs maintain weight loss after a patient stops taking injectable therapy?

ATTAIN-MAINTAIN enrolled patients who had completed an initial weight loss course on injectable Wegovy (semaglutide) or Zepbound (tirzepatide). Participants were then switched to either:

• Foundayo (orforglipron — Lilly’s oral GLP-1)
• Low-dose Zepbound (maintenance injectable)

Over 52 weeks of maintenance therapy:

• Patients on low-dose Zepbound regained an average of just 0.9 kg
• Patients on Foundayo regained an average of 5.0 kg

SURMOUNT-MAINTAIN showed a similar pattern — most of the weight loss achieved on full-dose Zepbound was retained when patients moved to the low-dose maintenance formulation.

The maintenance angle is clinically significant. One of the well-documented challenges of GLP-1 therapy is weight regain after discontinuation. These trials suggest oral GLP-1s could play a role as long-term maintenance drugs following an initial course of injectable treatment.

Viking Therapeutics — VK2735 Phase 2

Viking Therapeutics presented additional data from its Phase 2 VENTURE-Oral Dosing trial on May 12. VK2735 is a dual GLP-1/GIP receptor agonist — the same receptor combination as tirzepatide — with both subcutaneous and oral formulations in development.

The oral tablet formulation places Viking in direct competition with Novo’s Wegovy pill and Lilly’s Foundayo. The oral GLP-1 category is no longer a two-horse race. Viking has not yet announced Phase 3 timing for the oral formulation, but the program continues to advance as a credible third entrant.

MFN Pricing Context

In parallel with the clinical readouts, Novo Nordisk and Eli Lilly both struck “most favored nation” (MFN) pricing deals with the Trump administration. Both companies agreed to lower prices for their GLP-1 medications for Medicare and Medicaid recipients via the TrumpRx platform, which launched in January 2026. The pricing structure affects both injectable and oral formulations across the category.

What It Means

Several themes emerge from ECO2026:

Oral GLP-1s are no longer experimental. With Wegovy pill on the market, Foundayo recently approved, and Viking’s VK2735 advancing through Phase 2, oral formulations are becoming a serious commercial category rather than a research aspiration.

Maintenance therapy is a new clinical frontier. The injectable-then-oral handoff pattern shown in Lilly’s MAINTAIN trials addresses one of the most persistent problems in obesity care — weight regain after discontinuation.

The race is now three-way, not two-way. Viking’s entry materially changes the competitive landscape that has been defined by the Novo–Lilly duopoly.

Pricing is moving down across the category. MFN deals plus competition from oral formulations are creating downward pressure on what has historically been a premium-priced drug class.

The next major readout window for the category is expected later in 2026 as Lilly’s Phase 3 orforglipron program matures and Viking’s Phase 3 trials advance.