LIXIPARK
(2024)Objective
To assess the effect of lixisenatide on the progression of motor disability in persons with early Parkinson's disease
Study Summary
• Lixisenatide group improved by 0.04 points while placebo group worsened by 3.04 points from baseline
• After 2-month washout, benefit persisted in off-medication state
• Gastrointestinal side effects were common (nausea 46%, vomiting 13%)
Intervention
Lixisenatide (GLP-1 receptor agonist) 10 µg daily for 14 days, then 20 µg daily subcutaneous injection vs placebo for 12 months, followed by 2-month washout
Inclusion Criteria
Age 40-75 years; Parkinson's disease diagnosed <3 years; stable dopaminergic therapy for ≥1 month; no motor complications; Hoehn and Yahr <3; MoCA ≥26
Study Design
Arms: 2 arms: Lixisenatide vs Placebo
Patients per Arm: 78 per arm (156 total enrolled)
Outcome
• Secondary: Off-medication MDS-UPDRS Part III at 14 months after washout showed 3-point benefit (not adjusted for multiplicity); other secondary endpoints similar between groups
Bottom Line
In participants with early Parkinson's disease, lixisenatide therapy resulted in less progression of motor disability than placebo at 12 months but was associated with significant gastrointestinal side effects. Longer and larger trials are needed to determine the effects and safety of lixisenatide in Parkinson's disease.
Major Points
- Phase 2, double-blind, randomized, placebo-controlled trial conducted at 21 centers in France
- 156 participants with Parkinson's disease diagnosed <3 years, receiving stable dopaminergic therapy, without motor complications
- Randomized 1:1 to subcutaneous lixisenatide or placebo for 12 months, followed by 2-month washout
- Baseline MDS-UPDRS part III scores approximately 15 in both groups; mean disease duration 1.4 years
- At 12 months, lixisenatide improved motor scores by -0.04 points vs worsening of 3.04 points with placebo (difference 3.08, P=0.007)
- At 14 months (off-medication state after 2-month washout), mean MDS-UPDRS part III was 17.7 with lixisenatide vs 20.6 with placebo
- Secondary endpoints (nonmotor symptoms, quality of life, levodopa equivalent dose) did not differ substantially between groups
- 36% of lixisenatide group required dose reduction from 20 µg to 10 µg daily due to side effects
- Nausea occurred in 46% receiving lixisenatide vs 12% placebo; vomiting in 13% vs 3%
Study Design
- Study Type
- Randomized controlled trial
- Randomization
- Yes
- Blinding
- Double-blind
- Sample Size
- 156
- Follow-up
- 12 months active treatment plus 2-month washout (14 months total)
- Centers
- 21
- Countries
- France
Primary Outcome
Definition: Change from baseline to month 12 in MDS-UPDRS part III score (on-medication state)
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| Worsened by 3.04 points (95% CI 1.46 to 4.62); score at 12 months: 18.8 | Improved by -0.04 points (95% CI -1.62 to 1.54); score at 12 months: 14.9 | - (0.86 to 5.30) | 0.007 |
Limitations & Criticisms
- Secondary endpoints did not substantially support primary endpoint results
- Trial duration only 12 months; longer studies needed to determine if effects persist
- High rate of gastrointestinal side effects (46% nausea, 13% vomiting) requiring dose reduction in 36% of lixisenatide group
- No imaging biomarkers (e.g., dopamine transporter imaging) used to monitor disease progression
- Only one dose of lixisenatide tested; other doses might have better efficacy or tolerability
- 2-month washout period may be insufficient to determine long-lasting effects
- Phase 2 trial with relatively small sample size; larger trials needed for confirmation
Citation
N Engl J Med 2024;390:1176-85