Retatrutide vs Berobenatide vs Enicepatide: Comparing the ADA 2026 Obesity-Pipeline Data
TL;DR: Pfizer's berobenatide (15.9% wt loss) and Roche's enicepatide (22.7%) trail retatrutide's 28.3% TRIUMPH-1 result at ADA 2026.
What New Obesity-Pipeline Data Came Out of ADA 2026?
The American Diabetes Association's 86th Scientific Sessions, held in New Orleans in early June 2026, produced a cluster of competing pipeline updates in the GLP-1 receptor agonist class. Alongside Eli Lilly's full TRIUMPH-1 data readout for retatrutide, two other manufacturers reported their own mid-stage obesity results: Pfizer with its investigational monthly-capable agonist berobenatide, and Roche with its agonist enicepatide.[1][2]
None of these three compounds are directly comparable in a strict clinical sense — they come from trials of different phase, duration, dosing schedule, and population — but together they sketch the competitive field a company like Lilly is trying to stay ahead of with retatrutide's Phase 3 TRIUMPH programme.
How Much Weight Loss Did Pfizer's Berobenatide Show?
VESPER-1 (weekly dosing, exploratory extension): a non-placebo-adjusted weight loss of 15.9% at week 60 overall (32 weeks into the extension) in participants who escalated to 2.4 mg weekly berobenatide, with no plateau observed. VESPER-3 (monthly dosing): up to 12.3% weight loss versus placebo at 28 weeks in participants without type 2 diabetes, reaching roughly 15% at the highest monthly dose over approximately 14 months, again with no plateau after transitioning from weekly to monthly dosing.
Source: Pfizer press release, 5 June 2026 (reported via BioSpace, Businesswire, Clinical Trials Arena)
The headline commercial claim is not raw efficacy but dosing convenience: if approved, berobenatide would be positioned as a potential first monthly-injection GLP-1 therapy, competing on adherence rather than peak weight loss. Pfizer plans roughly ten Phase 3 studies for berobenatide during 2026, covering weight management and comorbidities including knee osteoarthritis and sleep apnea, targeting a launch around 2028.[1] Analysts covering the data called it "solid but undifferentiated" against Wegovy HD's 20.7% and tirzepatide's roughly 22% — berobenatide's case rests on dosing frequency, not beating the standard of care on weight loss.[3]
How Much Weight Loss Did Roche's Enicepatide Show?
Trial: CT388-103, a 48-week Phase 2 study of enicepatide in adults with obesity. Result: up to 22.7% average weight loss at the highest dose, with the weight-loss curve showing no sign of a plateau at week 48 — suggesting further loss may be possible with longer treatment. Responders: 26% of highest-dose participants lost at least 30% of body weight. Tolerability: treatment discontinuations due to adverse events were 5.9% on enicepatide versus 1.3% on placebo, with gastrointestinal effects reported as mostly mild to moderate.
Source: Roche Media Release, roche.com, 1 June 2026
Roche also presented complementary Phase 2 data for petrelintide, an amylin-receptor analogue in its portfolio, and plans a Phase 2 combination trial pairing fixed doses of both agents by mid-2026, alongside advancing enicepatide independently toward Phase 3.[2] A companion study, CT388-104, separately evaluates enicepatide in people with obesity and type 2 diabetes.
How Do the Three Candidates Compare Side by Side?
| Compound | Trial (phase) | Duration | Reported weight loss | Developer |
|---|---|---|---|---|
| Retatrutide 12mg | TRIUMPH-1 (Phase 3) | 80 wks (104 wk ext.) | 28.3% (30.3% at 104wk) | Eli Lilly |
| Enicepatide (high dose) | CT388-103 (Phase 2) | 48 wks | 22.7% | Roche |
| Berobenatide (weekly, high dose) | VESPER-1 extension (Phase 2b) | ~60 wks total | 15.9% (non-adjusted) | Pfizer |
| Berobenatide (monthly, high dose) | VESPER-3 (Phase 2b) | ~14 months | ~15% | Pfizer |
Figures are as reported in each developer's own press materials for different trial phases, populations, and durations. This table is for contextual research reference only and is not a head-to-head clinical comparison.
The pattern that emerges is consistent with the underlying pharmacology: retatrutide's TRIUMPH-1 result comes from a Phase 3, triple-receptor (GLP-1/GIP/glucagon) mechanism, while both competitors are single-receptor GLP-1 agonists still in Phase 2. Historically in this drug class, added receptor targets have tracked with greater weight loss in matched comparisons — a pattern also discussed in our coverage of Lilly's preclinical quintuple-agonist data from the same ADA 2026 meeting.
Why Would a Company Pursue a Lower-Efficacy Candidate?
Dosing convenience as a differentiator
Berobenatide's pitch is injection frequency, not peak weight loss — a monthly option could appeal to patients who find weekly injections burdensome, independent of whether it matches tirzepatide or retatrutide on efficacy.
Combination potential
Roche is pairing enicepatide with its amylin-analogue petrelintide in a planned mid-2026 combination trial, echoing Novo Nordisk's cagrilintide/semaglutide approach of adding a second, complementary satiety pathway.
Market size supports multiple winners
Analyst commentary on ADA 2026 has generally framed the obesity market as large enough to support several differentiated products at once, even where efficacy differs materially between candidates.
What Should UK Researchers Take From This Competitive Landscape?
Berobenatide and enicepatide are unapproved, patent-protected investigational drugs confined to their sponsoring companies' registered trials. Neither is available for purchase, compounding, or research use from any lawful source, and Velox Peptides does not supply either. Their appearance at ADA 2026 is evidence that the receptor biology retatrutide research addresses — GLP-1, and in combination approaches, complementary pathways such as amylin signalling — continues to attract substantial investment from manufacturers beyond Lilly.
That competitive validation does not change retatrutide's own regulatory position in the UK. It remains an unlicensed investigational medicine with an NDA filing targeted for Q4 2026 in the US and no confirmed MHRA timeline; see our FDA approval timeline guide. Velox Peptides supplies retatrutide strictly as an HPLC-verified in vitro research reagent, with batch-specific certificates of analysis, and makes no therapeutic or weight-management claims for it.
Retatrutide is supplied as a research reagent only. It is not a medicine and has not been evaluated by the MHRA or FDA for use in our products. Not for human or veterinary use. Berobenatide and enicepatide are not Velox Peptides products and are not available for sale. See our Research Use Policy and MHRA Statement.
References
- Pfizer. Robust Phase 2b Efficacy and Favorable Tolerability Support Monthly Dosing for Pfizer's GLP-1 RA Berobenatide. 5 June 2026. pfizer.com
- Roche. Roche to present new data advancing its obesity portfolio at the American Diabetes Association's 2026 Scientific Sessions. 1 June 2026. roche.com
- Tech Times. Pfizer Berobenatide ADA Data: Monthly Dosing Aims at Wegovy, but Weight Loss Trails Zepbound. 8 June 2026. techtimes.com
- Eli Lilly and Company. Lilly's triple agonist, retatrutide, delivered powerful weight loss in pivotal Phase 3 obesity trial. 21 May 2026 / ADA 2026 data, 6 June 2026. investor.lilly.com
- BioSpace. Lilly and Novo face off at ADA 2026 as others seek to compete in obesity. June 2026. biospace.com
Frequently Asked Questions
How does retatrutide's weight-loss data compare to berobenatide and enicepatide?
Retatrutide's Phase 3 TRIUMPH-1 trial produced 28.3% average weight loss at 80 weeks (30.3% at a 104-week extension). Roche's enicepatide, in a 48-week Phase 2 trial, produced up to 22.7%. Pfizer's berobenatide produced up to 15.9% in a weekly-dosing extension and roughly 15% at its highest monthly dose. These figures come from different trial phases, populations and durations and are not a head-to-head comparison.
What is Pfizer's berobenatide and why is monthly dosing significant?
Berobenatide is Pfizer's investigational GLP-1 receptor agonist, reported in the Phase 2b VESPER-1 and VESPER-3 trials at ADA 2026. Its notable feature is a dosing profile supporting monthly injection alongside a weekly option, positioned as an adherence advantage even though its weight-loss percentages trail retatrutide and enicepatide. Pfizer plans roughly ten Phase 3 studies for berobenatide in 2026.
What is Roche's enicepatide and how strong is its Phase 2 data?
Enicepatide is Roche's investigational GLP-1 receptor agonist, evaluated in the Phase 2 CT388-103 trial reported around ADA 2026. At the highest dose, participants lost up to 22.7% of body weight over 48 weeks with no plateau, and 26% of highest-dose participants lost at least 30%. Discontinuations due to adverse events were 5.9% versus 1.3% on placebo. Roche plans to advance enicepatide toward Phase 3.
Are berobenatide or enicepatide available as research reagents?
No. Both are unapproved, patent-protected investigational drugs confined to their sponsoring companies' registered trials. Neither is available from any commercial source, sold by Velox Peptides, or lawful to source outside those trials. Velox Peptides supplies retatrutide as an HPLC-verified in vitro research reagent; it does not supply berobenatide or enicepatide.
What should UK researchers take from this competitive landscape?
Multiple well-funded competitors validate the underlying GLP-1/incretin receptor biology that retatrutide research addresses, and signal more comparative literature ahead. None of this changes retatrutide's UK regulatory position: it remains an unlicensed investigational medicine, available to Velox Peptides customers strictly as an in vitro research reagent under the Human Medicines Regulations 2012, not as a treatment.