Landmark 308 · Trial in people
AKST4290 (TEAL)
Did not beat placebo in 110 people over 12 weeks. Both groups improved a little, and placebo slightly more.
In short
A 110-person, 12-week Phase 2 trial of a pill that blocks the immune receptor CCR3 found no advantage over placebo on its main motor measure.
- What it is
- Trial in people
- Outcome
- Did not work
- When
- 2020–2021
- Size
- 110 people · Phase 2
- Approach
- Look beyond the brain
- Research lane
- Inflammation & immunity
- Trial registry
- NCT04369430
- Last checked
- 19 Oct 2026
The research record
This is the project's file for this landmark, as written and checked. Sources are listed at the end; anything not yet confirmed is marked "Not yet verified".
Who
Alkahest, Inc. Sites included the US, Estonia and Germany. Alkahest had licensed the molecule from Boehringer Ingelheim (per a search summary of the conference abstract; not checked at source).
What happened
CCR3 is a receptor on immune cells that responds to eotaxin (CCL11), a signal that rises with age. AKST4290 blocks it. The idea is that this calms brain inflammation, following landmark 52, which found activated immune cells in the nigra.
TEAL (NCT04369430) enrolled people with Parkinson's on stable dopamine treatment (Hoehn and Yahr stage 2.5 or less). Of 110 randomised, 55 got 400 mg AKST4290 twice a day and 55 placebo, for 12 weeks. About 93 finished (46 and 47). The main measure was the change in off-medication movement score (MDS-UPDRS Part 3; lower is better). The drug group changed by minus 4.2 points and the placebo group by minus 5.1, so placebo improved slightly more. Both groups improved, which is common in short trials with a placebo. Serious adverse events: 1 of 52 on the drug and 3 of 55 on placebo.
Some secondary scores favoured the drug (for example the patient quality-of-life mobility score and the clinician severity score), but the primary result was null.
Why it moved us toward a cure
This was the first controlled test of a drug aimed at the immune system's chemokine signals in Parkinson's. A null result over 12 weeks does not rule out slower effects, but the measure was a symptom score, not progression, so the trial could not show slowing even if the drug worked.
Outcome
Dead end for this drug in this design. I found no Phase 3 plan. Alzforum (updated Oct 2021) says no results were made public.
Sources
- ClinicalTrials.gov NCT04369430 (API, results section, 19 Oct 2026)
- Alzforum: AKST4290
- TEAL design abstract, MDS Virtual Congress 2020
- Not yet verified: any peer-reviewed paper or company release; statistical tests behind the secondary results; the Boehringer Ingelheim origin; whether Parkinson's development has formally stopped.
How it connects
Built on
- builds on Inflammation in the Parkinson's nigra · 1988
Led to
None recorded.