The American Diabetes Association’s 2026 Scientific Sessions delivered what many in the research community expected - Eli Lilly’s retatrutide confirmed its position as the most potent weight-loss compound in clinical development. But the conference also revealed a problem for Lilly’s competitors: they are struggling to differentiate their offerings from drugs already on the market.
Reporting from BioPharma Dive covering the ADA presentations highlighted three notable datasets from Lilly, Pfizer, and Roche. The picture that emerged is one of a market where the bar for entry keeps rising, and not everyone is clearing it.
Lilly’s Triple Agonist Sets the Standard
Retatrutide operates on a mechanism that no currently approved drug uses - it targets three gut hormone receptors simultaneously (GLP-1, GIP, and glucagon). This “triple G” approach is producing weight loss figures that surpass anything in the existing pipeline.
At ADA, analysts from RBC Capital Markets described Lilly as reinforcing its “dominance” in the obesity space. UBS Securities noted that retatrutide gives Lilly’s franchise the kind of “durability and growth” that could extend to 2030 and beyond, even as pricing pressures mount and generic competition eventually arrives.
The data positions retatrutide as a step-change rather than an incremental improvement. For the research community, this validates the multi-agonist hypothesis - that targeting multiple hormonal pathways simultaneously produces superior results to single or dual agonism.
Pfizer’s Berobenatide: Strong Numbers, Tolerability Questions
Pfizer presented data on berobenatide, its oral GLP-1 candidate. The weight loss figures were described as “in line” with Lilly’s Zepbound (tirzepatide), which is a solid result for a compound that is not yet on the market.
However, the tolerability data raised concerns. RBC’s Trung Huynh noted that study discontinuation rates reached as high as 21% in trials evaluating monthly dosing. Cross-trial comparisons always come with caveats, but nausea, vomiting, and diarrhea appeared more frequent in Pfizer’s studies than what is observed with Zepbound.
Pfizer is positioning berobenatide as a “foundational medicine” with potential as both monotherapy and in combination regimens. The company has 10 planned or ongoing Phase 3 trials, with the first late-stage results potentially arriving in the second half of 2027. Monthly regimen data might follow in 2028.
As Leerink Partners’ David Risinger put it: “We need to see Phase 3 monthly efficacy and tolerability results in 2028 to understand its profile.”
Roche’s Enicepatide: A Late Entry Without a Clear Niche
The most challenging presentation came from Roche, which showed data on enicepatide (also known as CT-388), a dual injectable therapy. The highest dose produced placebo-adjusted weight loss of 18% to 22.5% depending on the efficacy measure - numbers just above Zepbound’s pivotal results.
The problem, as Jefferies analyst Michael Leuchten noted, is that the side effect profile appeared “modestly worse” than what is already available. The Jefferies team questioned how Roche might position a treatment that is “largely undifferentiated” and well behind multiple other options.
RBC’s Huynh was more blunt: “These results do little to differentiate enicepatide from its peers and position it as a late-comer, me-too option if it ever reaches the market.”
What This Means for the Research Community
The ADA 2026 data paints a clear picture of where obesity drug research is heading:
- Multi-agonist mechanisms are winning - retatrutide’s triple-receptor approach is producing results that single and dual agonists cannot match
- Oral formulations are the next frontier - Pfizer’s berobenatide is one of several oral GLP-1 candidates in late-stage development, but tolerability remains a hurdle
- Differentiation is getting harder - as the efficacy bar rises, new compounds need to offer something clearly distinct to justify their development
For researchers studying GLP-1 and related compounds, the takeaway is that the field is moving rapidly from “does this work?” to “how does this compare to what exists?” That shift has implications for study design, endpoint selection, and how research priorities are set.
What to Watch
- Retatrutide Phase 3 results - expected to define the next generation of obesity treatment
- Pfizer’s 2027-2028 data readouts - will berobenatide’s tolerability improve in larger trials?
- Roche’s strategic decisions - whether to continue development or pivot enicepatide to other indications
- Australian TGA pipeline - how these compounds move through the Australian regulatory pathway
Sources
- BioPharma Dive: “At a big meeting for weight loss drugs, Lilly’s ’triple G’ therapy set a new standard” (ADA 2026 coverage) - biopharmadive.com
- RBC Capital Markets analyst note: ADA 2026 Obesity Drug Coverage (June 2026)
- UBS Securities analyst note: Lilly Obesity Franchise Outlook (June 2026)
- Jefferies analyst note: Roche Enicepatide ADA Data Review (June 2026)
Disclaimer: This article is for educational and informational purposes only. It does not constitute medical advice, therapeutic recommendations, or endorsements of any compound. Grey Highway is a research-education community. We do not sell, supply, or promote the use of research compounds. Always consult a qualified healthcare professional regarding health decisions. For Australian regulatory information, visit the TGA website.