The European Congress on Obesity 2026 runs May 12–15 in Istanbul and is the next major obesity-medicine readout cycle after the Q1 earnings season. Novo Nordisk leads the abstract count with 52 presentations spanning the full STEP UP data for Wegovy 7.2 mg (following the April 7 launch and Q1 contribution), CagriSema higher-dose Phase 3 plans (after the February 2026 head-to-head loss against tirzepatide and the May 6 Q1 disclosure that the single-chamber co-formulation was discontinued), Wegovy pill efficacy and tolerability, and women's-obesity, perimenopause, and migraine subgroups.
A 21-expert global panel of obesity and cancer specialists is also expected to formally present a research proposal for a 10-year prospective trial testing GLP-1 receptor agonists for prevention of obesity-related cancers — building on SELECT cardiovascular benefit data, real-world dementia-incidence reductions, and the Lancet Psychiatry mental-health cohort. AstraZeneca's eleglipron full Phase 2b data from VISTA and SOLSTICE is on the ADA 2026 schedule the following month.
Stories here cover ECO readouts and the surrounding obesity-pharmacology calendar. See #wegovy, #cagrisema, and #novo-nordisk.
Eli Lilly published SURMOUNT-MAINTAIN in The Lancet and ATTAIN-MAINTAIN in Nature Medicine on May 12, with concurrent presentation at ECO 2026 in Istanbul. SURMOUNT-MAINTAIN tested lower-dose Zepbound (tirzepatide 5 mg) vs maximum tolerated dose: at week 112, MTD preserved all weight loss while the 5 mg arm lost only 5.6 kg additional. ATTAIN-MAINTAIN tested Foundayo (orforglipron) as a switch from injectable GLP-1s in SURMOUNT-5 participants: orforglipron preserved 79.3% of injectable-phase weight loss vs 37.6% on placebo at week 52; Wegovy MTD switchers regained only 0.9 kg, Zepbound MTD switchers regained 5.0 kg. The dual readout reframes the maintenance-versus-discontinuation conversation: dose-tapering and oral-switching strategies now have Phase 3 evidence behind them, validating the long-term-treatment chronic-disease framing.
Viking Therapeutics presented full 13-week Phase 2 VENTURE-Oral data at ECO 2026 May 12 in Istanbul: once-daily oral VK2735 produced statistically significant, dose-dependent mean weight loss up to 12.2% (26.6 lbs) over 13 weeks with placebo-adjusted significance starting at Week 1. The favorable tolerability profile and rapid early onset of effect support Viking's Q4 2026 plan to initiate a Phase 3 trial of the oral formulation following positive FDA feedback. The data complements the Phase 3 VANQUISH-1 subcutaneous program (4,650 patients enrolled November 2025) and VANQUISH-2 in T2D+obesity (~1,000 patients, enrollment completed March 26, 2026). VK2735's dual GLP-1/GIP mechanism puts it in direct comparison with tirzepatide and the next-generation Mounjaro/Zepbound franchise.
Novo Nordisk presented new OASIS 4 subanalyses of the Wegovy pill (oral semaglutide 25 mg) at ECO 2026 on May 13. Nearly one third (29%) of patients were classified as 'early responders' — losing at least 10% body weight by week 16 — and continued treatment to 64 weeks for a mean 21.6% body weight loss vs 13.2% at four months. A separate physical function analysis showed 77.3% of patients with poor baseline physical function achieved clinically meaningful improvement (bending over, standing comfortably, staying active) vs 42.9% on placebo. The data adds to the OASIS 4 February 2026 16.6% mean weight-loss headline by stratifying patients on early response — a likely tool for prescribers thinking about dose escalation and persistence.
An ORION indirect treatment comparison presented at ECO 2026 on May 13 framed the head-to-head competition between Novo's Wegovy pill (oral semaglutide 25 mg) and Lilly's Foundayo (orforglipron 36 mg). The Wegovy pill delivered statistically significant greater mean weight loss than orforglipron, with patients on orforglipron showing approximately 14x higher odds of discontinuing treatment due to gastrointestinal side effects. The May 13 framing complements Novo's Q1 print disclosure that Wegovy holds 65% of all new US GLP-1 prescriptions; CEO Mike Doustdar's CNBC commentary called the moment a 'turnaround situation' for the Danish company. The ORION ITC matters as a prescriber-decision tool given the two compounds are now the only two FDA-approved oral GLP-1s for chronic weight management.
Novo Nordisk's CagriSema REDEFINE 1 treatment-target analysis presented as an oral presentation at ECO 2026 on May 12 reported that the cagrilintide + semaglutide combination drove a higher percentage of participants to clinically meaningful BMI and waist-to-height ratio (WHtR) targets than any monotherapy or placebo arm. 50.7% of CagriSema-treated participants reached BMI <30 at week 68 vs 10.2% on placebo, and participants reaching BMI <27 plus WHtR <0.53 showed normalization of cardiometabolic parameters at higher rates than non-achievers. A companion REDEFINE 1 cardiovascular risk analysis scheduled for May 14 ECO presentation tracks predicted atherosclerotic CVD risk reduction. The data complements the May 12 body-composition substudy (35.7% fat-mass loss vs 14.4% lean tissue loss).
Sector stock reaction across May 12-13: Novo Nordisk ADRs popped roughly 6% premarket May 12 on the early-responder + women's-data combination and the OASIS 4 mobility analyses; Eli Lilly traded flat as the SURMOUNT-MAINTAIN and ATTAIN-MAINTAIN dual publication confirmed expected maintenance positioning rather than producing fresh upside surprises. Analysts noted the broader 'long-term treatment' thesis — that GLP-1 obesity drugs are chronic-disease medications, not short courses — got concrete trial backing this week between SURMOUNT-MAINTAIN, ATTAIN-MAINTAIN, and STEP UP early-responder analyses. The week's narrative shift sets up the May 14-15 ECO Day 3+4 cycle and the May 29-June 2 ASCO 2026 meeting in Chicago — where peptide-drug conjugates (Bicycle BT8009, Avacta AVA6000, Pfizer FAP-Dox) take the next round of clinical-data spotlights.
A post-hoc analysis of the Phase 3 STEP UP trial presented Tuesday May 12 at ECO 2026 identified an 'early responder' subgroup — patients who lost at least 15% body weight within the first 24 weeks. About 27% of patients on the higher-dose Wegovy 7.2 mg dose met that threshold vs 21% on the 2.4 mg dose and 3% on placebo. Early responders went on to lose a mean 27.7% body weight at week 72 (vs the 21% headline mean across all 7.2 mg patients). The analysis also confirmed that 84% of weight loss across both Wegovy doses came from fat mass, with muscle function preserved. The data sharpens the case for early-response-based dose decisions in the post-launch real-world workflow.
A second post-hoc analysis of STEP UP presented Tuesday found Wegovy 7.2 mg delivered consistent weight loss across reproductive life stages: 22.6% premenopausal, 19.7% perimenopausal, 19.8% postmenopausal, with 41.4% of premenopausal women hitting ≥25% loss. Waist-circumference reductions: 17.5%, 15.6%, 15.3% respectively. Separately, a real-world analysis of 34,000+ women showed that those taking Wegovy had a 42-45% lower migraine risk and a 25% lower depression risk starting six months in versus those on menopausal hormone therapy alone. The real-world data lands as observational signals that warrant prospective study — not as proof of causation — but reinforces the cardiovascular and quality-of-life narrative for the women's-health subgroup.
A prespecified body-composition substudy of REDEFINE 1 presented at ECO 2026 reported that 252 participants on CagriSema 2.4 mg/2.4 mg (semaglutide + cagrilintide) achieved a 35.7% relative reduction in fat mass and a 14.4% reduction in lean soft-tissue mass at week 68 — compared with 5.7% and 4.3% on placebo. The headline 22.7% mean weight reduction in REDEFINE 1 (NEJM publication June 2025) thus broke down with a fat-mass-to-lean-tissue ratio of roughly 2.5:1, a more favorable body-composition profile than the typical 1.5-2:1 ratio reported for GLP-1 monotherapy. The data builds the case for combination amylin-GLP-1 therapy as preferentially fat-selective.
Real-world data presented in the ECO 2026 cycle counters the trial-based efficacy headlines: a Prime Therapeutics commercial claims analysis (cited in the May 2026 Managed Healthcare Executive cover story) found just 8.1% of members persisted with anti-obesity GLP-1 medications for three years. A separate 6-month Medicaid persistence analysis showed roughly 61% staying on treatment at six months. The high attrition is driven primarily by GI tolerability, insurance turnover, and out-of-pocket costs after step-edit programs. For newer agents like semaglutide and tirzepatide, post-discontinuation weight regain averages 0.8 kg per month — projecting return to baseline by ~1.5 years. PBM programs (Optum Rx Weight Engage, Rightway, MedImpact GLP-1 Benefit 360) are now embedding multidisciplinary support to lift persistence above the current floor.
Viking Therapeutics announced two poster presentations at ECO 2026 in Istanbul (May 12-15) on its VK2735 dual GLP-1/GIP agonist program. The first poster details 13-week efficacy and safety data from the Phase 2 VENTURE-Oral trial of oral VK2735, supporting Viking's Q4 2026 plan to launch a Phase 3 trial of the oral formulation following positive FDA feedback. The second poster details Phase 3 VANQUISH-1 design and enrollment demographics for subcutaneous VK2735, which completed enrollment of approximately 4,650 adults with obesity in November 2025. VANQUISH-2 (subcutaneous VK2735 in T2D + obesity, ~1,000 adults) completed enrollment March 26, 2026. Posters display May 12-15 with networking sessions Thursday May 14 18:00-19:15 TRT.
Ascletis Pharma will present multiple poster sessions at ECO 2026 covering programs beyond the already-presented ASC30. ASC47, an adipose-targeting thyroid hormone receptor beta (THRβ) agonist designed for muscle-preserving weight loss, demonstrated up to 111.8% greater relative weight loss when combined with semaglutide vs semaglutide monotherapy in obesity participants. ASC36, a once-monthly next-generation amylin receptor agonist peptide, posted a 32-day average observed half-life — six times longer than Zealand's petrelintide. ASC35, a once-monthly next-generation GLP-1R/GIPR dual agonist peptide, showed a 14-day average observed half-life (six times longer than tirzepatide) and 71% more relative weight loss than tirzepatide in a diet-induced obesity mouse model. Session Thursday May 14, 18:00-19:15 TRT.
Prof. Luca Busetto (University of Padova) and colleagues will present at ECO 2026 a pooled subgroup analysis of 358 adults aged 65 and older (mean age 69, 72% women) drawn from STEP 1, 3, 4, 5, 8, and 9 — 248 received semaglutide 2.4 mg, 110 placebo. The semaglutide arm lost 15.4% body weight on average vs 5.1% on placebo; 46.8% of semaglutide users hit ≥15% weight loss vs 6.4% on placebo, and 28.6% reached ≥20% vs 2.7%. Waist circumference fell 14.3 cm vs 6.0 cm. 27% on semaglutide reached a healthy BMI (<27) vs 5.5%. Serious adverse events occurred in 19.0% on semaglutide vs 12.7% on placebo. The analysis complements Lilly's ECO 2026 orforglipron 65+ subgroup analysis from ATTAIN-1 and ATTAIN-2 — both filling the geriatric data gap for the first generation of mainstream obesity drugs.
Prof. John Wilding (University of Liverpool) and colleagues will present at ECO 2026 a real-world observational study tracking obesity-linked complication rates by degree of GLP-1-driven weight loss. In the year following GLP-1 treatment initiation, 27.0% of patients had BMI reductions <5%, 22.4% had 5-<10%, 14.1% had 10-<15%, 15.8% had ≥15%, and 20.8% gained BMI. Over a mean 11-month follow-up, patients with ≥15% BMI reduction had 37% lower osteoarthritis odds, 30% lower CKD odds, 69% lower OSA odds, and 32% lower heart failure odds versus those with 0-5% reduction (all statistically significant except heart failure). Incidence per 1,000 person-years: 21.4 OA, 21.1 CKD, 20.3 OSA, 3.9 HF. The data quantifies the value of pushing for deeper weight loss rather than cruise-control dosing.
Ascletis announced multiple poster presentations at the 33rd European Congress on Obesity (ECO 2026) opening May 12 in Istanbul. ASC30, a first-in-class small-molecule GLP-1R fully biased agonist developed for once-daily oral and once-monthly to once-quarterly subcutaneous dosing, will be featured across formulation, PK, and clinical-data posters. The Phase 2 13-week study previously reported 7.7% placebo-adjusted weight loss at 60 mg oral dosing; the once-monthly subQ depot formulation achieved 7.5% placebo-adjusted weight loss at 16 weeks after three monthly doses, with topline T2D Phase 2 data expected Q3 2026. The subQ depot angle directly challenges Pfizer's MET-097i monthly thesis with a different mechanism (small-molecule GLP-1R biased agonist vs ultra-long-acting peptide).
A post-hoc subgroup analysis of Eli Lilly's orforglipron (Foundayo) in adults aged 65 and older, drawn from the ATTAIN-1 and ATTAIN-2 Phase 3 programs, will be presented at ECO 2026 in Istanbul May 12-15. The analysis pools 616 randomized participants (613 treated) — 118 on 6 mg, 135 on 12 mg, 146 on 36 mg orforglipron, and 214 placebo — across patients with and without type 2 diabetes. The geriatric data set addresses a long-standing clinical gap: incretin trials have systematically underenrolled adults over 65, the population most affected by obesity-related comorbidities and the most likely to face polypharmacy-related GI tolerability concerns. Lead author Dr. Deborah Horn (UTHealth Houston McGovern Medical School). The presentation is among the ECO 2026 abstracts that will shape geriatric prescribing patterns for the first FDA-approved GLP-1 pill that does not require fasting or water restrictions.
Two of the year's biggest peptide-related meetings open within 24 hours of each other next week. The European Congress on Obesity 2026 runs May 12–15 in Istanbul, with Novo Nordisk presenting 52 abstracts spanning Wegovy 7.2 mg full STEP UP data, CagriSema higher-dose Phase 3 plans, Wegovy pill efficacy and tolerability, and women's-obesity / perimenopause / migraine subgroups; the 21-expert global panel will also formally propose the 10-year prospective GLP-1 cancer-prevention trial. TIDES USA 2026 runs May 11–14 in Boston with six concurrent scientific tracks across oligonucleotides, peptides, and mRNA — featuring Bachem, PolyPeptide, CordenPharma, Gilead, and Novo Nordisk on the CMC strategy and GMP capacity panels. Hims & Hers prints Q1 May 11 the same evening.
Ahead of the European Congress on Obesity in Istanbul (May 12–15), a 21-expert global panel of obesity and cancer specialists will present a research proposal for a 10-year prospective trial testing GLP-1 receptor agonists like semaglutide and tirzepatide for prevention of obesity-related cancers. The proposal builds on the SELECT trial's established cardiovascular benefit, real-world dementia-incidence reductions, and the broader case that GLP-1s influence multiple aging-driven disease categories. The Istanbul meeting is the same venue where Novo Nordisk will present 52 abstracts on Wegovy, the higher-dose 7.2 mg formulation, the Wegovy pill, and CagriSema, including data on women's obesity, perimenopause, and migraine.