Claimed effect · Exenatide

Does Exenatide help with parkinson's disease progression?

B
Grade B — probable, not settled1 phase 3 RCT (n=194, 96 wk) — negative; 1 phase 2 positive · effect size: not measurable
Short answerProbable, not settled. Human data exist (1 phase 3 RCT (n=194, 96 wk) — negative; 1 phase 2 positive) and mostly agree, showing no measurable effect, or none yet shown — but too few, too small, or not yet peer-reviewed for a firm answer. After a positive 62-person phase 2 in 2017, the 194-person phase 3 found motor scores worsened equally on exenatide and placebo over 96 weeks. The Lancet's editors have since issued an Expression of Concern on the phase 3 paper; the notice does not change the result, but readers should know it exists.

What the studies show

After a positive 62-person phase 2 in 2017, the 194-person phase 3 found motor scores worsened equally on exenatide and placebo over 96 weeks. The Lancet's editors have since issued an Expression of Concern on the phase 3 paper; the notice does not change the result, but readers should know it exists.

“At 96 weeks, MDS-UPDRS III OFF-medication scores had increased (worsened) by a mean of 5·7 points (SD 11·2) in the exenatide group, and by 4·5 points (SD 11·4) points in the placebo group (adjusted coefficient for the effect of exenatide 0·92 [95% CI -1·56 to 3·39]; p=0·47).”

Verbatim, from the abstractVijiaratnam N, Girges C, Auld G, et al. Exenatide once a week versus placebo as a potential disease-modifying treatment for people with Parkinson's disease in the UK: a phase 3, multicentre, double-blind, parallel-group, randomised, placebo-controlled trial. Lancet, 2025

Human trials exist and mostly agree, but there are too few of them, they are too small, or one big one is still reading out. Expect the grade to move.

  1. 1
  2. 2
    Athauda D, Maclagan K, Skene SS, et al. Exenatide once weekly versus placebo in Parkinson's disease: a randomised, double-blind, placebo-controlled trial.Lancet, 2017Phase 2; 62 participants; positive on the off-medication motor score — the result the phase 3 was designed to confirm.
  3. 3

In context

Exenatide is a synthetic copy of exendin-4, a peptide from Gila-monster saliva, and the drug that opened the GLP-1 class in 2005. It is approved for type 2 diabetes as a twice-daily injection and a weekly one. In the 14,752-person EXSCEL trial it was safe but did not significantly reduce cardiovascular events, unlike the drugs that followed it. A phase 3 trial testing it as a disease-modifying treatment for Parkinson's disease, the use it is most searched for today, found no benefit. It is prescription-only.

Exenatide is approved (rx). Legal status differs by country — see the regulation section or the jurisdiction pages.

Questions

Is Exenatide proven to help with parkinson's disease progression?
Not yet settled. 1 phase 3 RCT (n=194, 96 wk) — negative; 1 phase 2 positive — LYO grades it B, meaning probable but liable to change as trials read out.
What studies are behind the grade?
After a positive 62-person phase 2 in 2017, the 194-person phase 3 found motor scores worsened equally on exenatide and placebo over 96 weeks. The Lancet's editors have since issued an Expression of Concern on the phase 3 paper; the notice does not change the result, but readers should know it exists.
Is Exenatide approved for this?
Exenatide is an approved medicine (Approved (Rx)); whether this particular outcome is a licensed indication is stated on the compound page's regulation section.

Other outcomes for Exenatide

Written and maintained by LYO Research — how pages are written and checked. Reviewed 10 September 2026. Grades count human evidence only; see how LYO grades. Not medical advice. Correct this page →