Metabolic peptide trial watchlist (2026 – 2028)

The next 24 months will reshape what UK clinicians and researchers consider settled about incretin pharmacology. Here are the Phase 3 read-outs to track, ordered by expected date. Where a trial has already reported, the row is included for context.

1. FLOW

   Phase 3Novo Nordisk

   Expected: Reported 2024 (24% reduction)

   Compound: Semaglutide

   Population: T2DM with CKD (eGFR 50-75 / UACR >100)

   Primary endpoint: Composite kidney endpoint

   Already reported — included for context. FLOW is the foundational renal-outcomes trial for the GLP-1 class.

   Registry / publication

2. SUMMIT

   Phase 3Eli Lilly

   Expected: Reported 2024

   Compound: Tirzepatide

   Population: HFpEF + obesity

   Primary endpoint: KCCQ-CSS + 6MWT

   Already reported — tirzepatide's parallel to STEP-HFpEF. Positive: KCCQ-CSS +6.9 points, 6MWT +18 m at 52 weeks.

   Registry / publication

3. TRIUMPH-1

   Phase 3Eli Lilly

   Expected: Q2 2026

   Compound: Retatrutide

   Population: Adults with obesity, without T2DM

   Primary endpoint: Percent weight change at 76 weeks

   First Phase 3 read-out for the triple-agonist class. Phase 2 produced ~24% mean weight reduction; TRIUMPH-1 will either confirm or moderate that signal at scale.

   Registry / publication

4. STEP-HFpEF follow-ups

   Phase 3Novo Nordisk

   Expected: 2026 extension data

   Compound: Semaglutide

   Population: HFpEF + obesity (extension cohorts)

   Primary endpoint: KCCQ-CSS + 6MWT durability

   Longer-term durability of STEP-HFpEF response. Question is whether benefit attenuates with continued dosing.

5. SURMOUNT-MMO

   Phase 3Eli Lilly

   Expected: H2 2026 – 2027

   Compound: Tirzepatide

   Population: Adults with BMI ≥27 + established CVD, without T2DM

   Primary endpoint: 3-component MACE

   Tirzepatide's parallel to SELECT. The first non-diabetic obesity CVOT for the dual-agonist class. Interim signals reported late 2025 were directionally consistent with semaglutide SELECT.

   Registry / publication

6. SURPASS-CVOT

   Phase 3Eli Lilly

   Expected: Q3 2026

   Compound: Tirzepatide

   Population: T2DM with established CVD

   Primary endpoint: 3P-MACE (non-inferiority vs dulaglutide; superiority secondary)

   Active-controlled rather than placebo-controlled. Will establish whether tirzepatide's CV signal extends beyond what dulaglutide (REWIND) already showed in T2DM.

   Registry / publication

7. Retatrutide NASH/MASH

   Phase 2Eli Lilly

   Expected: H2 2026

   Compound: Retatrutide

   Population: MASH (biopsy-confirmed)

   Primary endpoint: Histological NASH resolution without worsening fibrosis

   Whether the triple agonist's glucagon-receptor arm produces a hepatic-fat advantage over dual agonism. Mechanistically plausible (glucagon drives hepatic FAO).

8. TRIUMPH-2

   Phase 3Eli Lilly

   Expected: Q4 2026 – Q1 2027

   Compound: Retatrutide

   Population: T2DM + obesity

   Primary endpoint: Percent weight change + HbA1c reduction

   Dual primary endpoints — glycaemic control alongside weight. Whether glucagon co-agonism harms glycaemic control in T2DM is one of the central open questions.

   Registry / publication

9. SURMOUNT-OSA follow-up

   Phase 3Eli Lilly

   Expected: H1 2027

   Compound: Tirzepatide

   Population: Moderate-to-severe OSA + obesity (extension)

   Primary endpoint: AHI durability + CPAP dependence

   Whether the SURMOUNT-OSA AHI reduction translates into reduced CPAP dependence or improved quality-of-life metrics longer-term.

10. TRIUMPH-3

    Phase 3Eli Lilly

    Expected: H2 2027

    Compound: Retatrutide

    Population: Obesity + cardiovascular disease

    Primary endpoint: MACE composite (after weight efficacy phase)

    Retatrutide's CV outcomes arm. Will lag TRIUMPH-1/2 by ~12 months. Read-out informs whether triple-agonism extends the SELECT-class CV signal further.

    Registry / publication