On June 9, 2026, Kenneth Custer — Executive Vice President and President of Lilly Cardiometabolic Health — sat down for a fireside chat at the Goldman Sachs 47th Annual Global Healthcare Conference.

He had just come from the American Diabetes Association's 85th Scientific Sessions, where Lilly had presented data on eloralintide — their investigational selective amylin receptor agonist — in combination with tirzepatide.

What he said at Goldman Sachs was worth paying attention to.

According to reporting from the presentation, Custer framed GIP, GLP-1, and amylin as, in his assessment, the three nutrient-stimulated hormones that ultimately belong together in a medicine.

That is not a casual comment from someone in his position.

Why the Conference Framing Matters

Investor conferences are not research papers. They are strategic communications — carefully chosen words from executives who understand that what they say publicly shapes analyst models, investor expectations, and competitive positioning.

When the EVP of Cardiometabolic Health at Eli Lilly publicly names three specific biological pathways as the combination he believes belongs in a single medicine — days after presenting combination study data at ADA — he is not speculating. He is describing a direction.

Combined with everything else Lilly has shown in 2026, this is the clearest public signal yet of where the company believes obesity medicine is heading.

The Evidence Trail

The Goldman Sachs comment does not stand alone. It sits at the end of a sequence of events.

November 2025 — Eloralintide Phase 2 data published in The Lancet

Lilly presented positive Phase 2 results for eloralintide, a once-weekly injectable selective amylin receptor agonist, at ObesityWeek 2025. The results were simultaneously published in The Lancet.

In 263 adults with obesity or overweight (without type 2 diabetes), eloralintide produced mean weight reductions ranging from 9.5% at 1 mg to 20.1% at 9 mg at 48 weeks, compared to 0.4% with placebo. This was standalone data — eloralintide alone, no GLP-1 agent added.

For context: semaglutide (Wegovy) achieves approximately 14.9% at 68 weeks. Eloralintide at 9 mg — from a completely different biological pathway — produced comparable weight loss in 48 weeks as monotherapy.

June 2026 (ADA 85th Scientific Sessions) — Combination data presented

At ADA 2026, Lilly presented data from a study evaluating eloralintide with tirzepatide. The study design was notable: rather than starting both compounds simultaneously, tirzepatide was administered first, and eloralintide was added subsequently.

That sequential design mirrors a real-world clinical scenario: a patient reaches a plateau on their existing GLP-1 or dual agonist, and a complementary pathway is added. Lilly was not just testing a compound combination. They were testing a clinical strategy.

June 9, 2026 — Goldman Sachs conference

Three days after the ADA presentations, Custer publicly framed GIP + GLP-1 + amylin as the three-hormone combination he believes belongs together.

The progression from Phase 2 data → combination study design → executive strategic framing is not coincidental.

The Novo Nordisk Parallel

Lilly is not operating in isolation. Novo Nordisk has been pursuing an identical strategic thesis through a different compound.

CagriSema — Novo's combination of semaglutide (GLP-1) with cagrilintide (an investigational amylin analog) — produced 22.7% mean weight loss at 68 weeks in REDEFINE-1, presented at ADA 2026. Novo has framed CagriSema's safety profile as comparable to the GLP-1 RA class.

Two of the largest pharmaceutical companies in obesity medicine have independently invested billions of dollars into the same biological category — amylin — as a complement to incretin therapy.

When the two dominant players in a field converge on the same scientific thesis, it is worth understanding why.

What Amylin Actually Does — and Why It's Different

GLP-1 receptor agonists and GIP/GLP-1 dual agonists have driven the current generation of obesity medicine. Their primary mechanism involves appetite suppression, delayed gastric emptying, and improved insulin sensitivity — operating through incretin biology.

Amylin is a different hormone entirely. It is co-secreted with insulin from pancreatic beta cells in response to meals. Its physiological roles include:

Satiety signaling — amylin acts on the area postrema in the brainstem, a region involved in meal termination that is anatomically distinct from GLP-1's primary central nervous system targets
Gastric emptying regulation — slows the rate at which food moves from the stomach
Appetite and food reward modulation — influences the hedonic (reward-based) aspects of eating, not just the homeostatic (hunger-driven) aspects

The key mechanistic point: amylin and GLP-1 appear to act on overlapping but distinct neural circuits. This is the biological basis for the "complementary, not competing" thesis. Two pathways addressing different aspects of the same problem may produce synergistic outcomes — as the combination data from both Lilly and Novo appears to suggest.

The Generational Framework

The history of obesity pharmacology in the GLP-1 era follows a clear progression:

Generation 1 — GLP-1 alone Semaglutide (Wegovy, Ozempic). Approximately 15% weight loss at 68 weeks. FDA-approved for weight management (2021) and cardiovascular risk reduction (2024).

Generation 2 — GLP-1 + GIP Tirzepatide (Zepbound, Mounjaro). Approximately 22.5% weight loss at 72 weeks. FDA-approved for weight management (2023) and cardiovascular outcomes data emerging.

Generation 3 — Triple agonism (GLP-1 + GIP + glucagon) Retatrutide (investigational). TRIUMPH-1 Phase 3 data: 28.3% weight loss at 80 weeks, 30.3% at 104 weeks in extension. Not yet FDA-approved.

Generation 4 — Incretin + amylin Both Lilly (eloralintide + tirzepatide) and Novo (CagriSema) are building toward this. Neither compound combination is approved. Both are in active clinical development.

It is important to be precise here: "Generation 4" is a conceptual framework, not a formal clinical designation. The combinations being studied are investigational. Results from Phase 2 and early Phase 3 work are promising, but the pathway from current data to FDA approval is measured in years.

What This Means — and What It Doesn't

What it means: The two largest obesity drug developers in the world are independently placing major bets on amylin as the next layer of metabolic pharmacology. The scientific rationale — complementary mechanism, distinct neural targets, additive effects in early data — is coherent and well-grounded. The strategic signals from Lilly's executive team suggest this is not peripheral research but a core pipeline priority.

What it doesn't mean: No amylin-based combination therapy is FDA-approved for obesity as of this writing. Eloralintide is investigational. CagriSema is investigational. Combination therapies face additional regulatory complexity compared to monotherapies. Phase 2 data does not predict Phase 3 outcomes with certainty, and long-term safety data in large populations does not yet exist for these compounds.

The pattern being described here is a directional signal — where the scientific and commercial momentum is pointing. It is not a prediction about approvals, timelines, or individual patient outcomes.

Staying Informed

The obesity pharmacology landscape is moving faster than most people can track. Eloralintide's Phase 2 data appeared in The Lancet in November 2025. CagriSema Phase 3 data was presented at ADA in June 2026. The combination study designs are now public. And Lilly's senior leadership is framing the three-hormone thesis publicly.

Understanding where this field is heading — and what the evidence actually shows at each stage — is exactly what PeptidesGPT's AI Coach is designed to deliver.

→ Ask the Coach at PeptidesGPT.com

Sources:

Lilly PR Newswire: Goldman Sachs 47th Annual Global Healthcare Conference announcement (May 27, 2026)
Seeking Alpha: LLY Goldman Sachs 47th Annual Global Healthcare Conference 2026 transcript (June 9, 2026)
Lilly PR Newswire: Eloralintide Phase 2 results (November 6, 2025)
The Lancet: Eloralintide Phase 2 publication (ObesityWeek 2025)
Novo Nordisk PR Newswire: CagriSema REDEFINE-1/REDEFINE-2 ADA 2026 presentation (June 2026)
Lilly Trials: Eloralintide + tirzepatide combination study (trials.lilly.com)

PeptidesGPT is an educational platform. The content above discusses investigational compounds and clinical research for informational purposes only. It is not medical advice. Eloralintide, CagriSema, and retatrutide are investigational and not FDA-approved for obesity treatment as of this writing. Always consult a licensed healthcare provider before making any decisions about your health or protocol.