Approach 6 of 6
Keep vulnerable cells alive
Why do these cells die first, and can we shield them?
26 steps since 1990. 3 moved us forward. Five drugs tested to shield these cells did not work. We now understand better why these cells are fragile. As of Oct 2026
Facts on this page checked 19–22 Oct 2026
Each dot is one step in this approach: a discovery, a new tool or a trial, by the year it started.
- 3 moved us forward
- 2 waiting for results
- 15 still open
- 1 overtaken by better ideas
- 5 dead ends
Where it stands
- How far it has got
- Step 3 of 5 · Testing whether it helps
- Has it slowed Parkinson's?
- Not yet shown
- Tried and did not work
- 5 trials
- Next result
- Nov 2026Low-dose lithium · Phase 1
The idea in brief
In Parkinson's, a small group of brain cells die first. These cells make dopamine, the chemical that helps you move smoothly. Nearby brain cells that look much the same are mostly spared. Scientists want to know why.
One answer is that these cells work very hard. They fire all day, and each time they fire, calcium flows in. In 2007, scientists found that this may put them under constant strain. In 2013, mapping and a computer model showed that each cell has a huge web of branches. Running it costs a great deal of energy.
In 2022, researchers found one type of these cells that is lost first. If we know what makes them fragile, we might shield them. This page is about drugs that try to do that.
How we got here
- Calcium channels and fragile cells · 2007
- The cost of a giant axon · 2013
- The most vulnerable cell type · 2022
- Nurr1 activators · 2015
What has been tried
Each row is one trial in people. Its dot shows how it turned out, using the same key as the chart above.
Results already in
7 trials
-
TCH346 · a pill meant to stop cells dying
Did not work
Made no difference in 301 people with early Parkinson's. It had protected cells in animals.
-
PRECEPT · CEP-1347, a pill meant to stop cells dying
Did not work
Stopped early in 806 people because it was clearly not working. It had protected cells in animals.
-
STEADY-PD III · isradipine, a blood-pressure pill
Did not work
Did not slow Parkinson's in 336 people over three years. The dose may have been too low to reach its target.
-
Nilotinib · a leukaemia drug
Did not work
Almost none of the drug reached the brain. It did not help in these two trials, which had 151 people in all.
-
Risvodetinib · a pill that blocks c-Abl, an enzyme
Mixed or early results
Safe in 137 people over 12 weeks. It did not clearly improve symptoms, and the study was too short to show slowing.
-
PROSEEK · vodobatinib, a leukaemia-type pill
Did not work
The drug reached the brain but did no better than placebo in 513 people. The trial was stopped in April 2024.
-
ROCK-PD · fasudil, a drug used in Japan for other illnesses
Mixed or early results
A three-week safety study in 81 people. It has finished, but no result is posted yet. It cannot show slowing.
Still to come
2 trials · dates are expected, not promised
The next result is due in Nov 2026, from Low-dose lithium. The largest trial still to report, Radotinib, is expected in Apr 2027.
-
Low-dose lithium · a small study in Buffalo, USA
Result due Nov 2026
Small studies of 15 to 35 people that measure blood and scan markers. They cannot show whether lithium slows Parkinson's.
Who: People with Parkinson's, in small studies · Last checked 22 Oct 2026
Details and sources: Low-dose lithium Check if it is recruiting: Low-dose lithium
-
Radotinib · a leukaemia drug
Result due Apr 2027
A small study in 43 people. It mainly checks safety, so it cannot show whether the drug slows Parkinson's.
Who: People with Parkinson's, in France · Last checked 22 Oct 2026
Details and sources: Radotinib Check if it is recruiting: Radotinib
In words
Of the 9 trials in people, 5 did not work, 2 had mixed or early results, and 2 have results due. The first is due in Nov 2026; the largest, Radotinib, in Apr 2027.
What the dead ends taught us
- Protecting cells in animals does not mean protecting them in people. Two drugs saved cells in animals. Neither helped in people. (PRECEPT; TCH346)
- The dose we can safely give may be too low. The blood-pressure drug isradipine did not slow Parkinson's. The calcium idea may still stand, because the dose people could take may have been too low. (STEADY-PD III)
- A drug must reach the brain. Nilotinib barely got into the brain, so it was never a fair test. (Nilotinib)
- Reaching the brain is not enough. Vodobatinib did get in, and still did not help. This weakens the c-Abl idea at the doses tested. (PROSEEK)
- Safe is not the same as works. Risvodetinib was safe, but it missed its main goal in a short study. (Risvodetinib)
Most drugs tested against any brain disease do not work. Each one that fails rules something out and shapes the next trial.
What it would mean for you
If a drug like this works, it would slow Parkinson's down. It would not bring back cells that are already lost. It would probably help most if started early.
Most of these drugs are pills. Some are old drugs used for other illnesses, but the dose and the risks for Parkinson's are not the same.
Some trials are still to report. A small study of low-dose lithium, Low-dose lithium, is expected in Nov 2026. It measures blood and scan markers, not symptoms, and it has no comparison group in its early parts. A radotinib study, Radotinib, is expected in Apr 2027. The fasudil trial, ROCK-PD, has finished, but its result is not yet posted. Expected dates are not promised, and trials often run late.
Drugs that switch on a cell-protecting gene called Nurr1 are still only tested in the lab and in healthy volunteers. Nobody with Parkinson's has taken them in a trial yet.
Should I try this now?
No. Please do not start any of these on your own.
- Lithium needs regular blood tests and has side effects. Do not take it for Parkinson's without your doctor.
- Leukaemia drugs such as nilotinib are not for Parkinson's.
- Fasudil and blood-pressure drugs should not be used to treat Parkinson's yourself.
If you wonder whether one of these might suit you, talk to your neurologist or Parkinson's nurse first.
Can I take part?
Most of these trials look for people with early Parkinson's. Some look for people who have not yet started dopamine medicines. Each trial sets its own rules, including age and how long ago you were diagnosed.
Related approaches
Sources, and the same lanes for researchers
This page is built from 26 research landmarks. Each has its own sources; follow "Details and sources" on any trial. Facts were checked 19–22 Oct 2026. The summary was written on 22 Oct 2026.
- Cell survival & anti-apoptosis (14 landmarks)
- Selective vulnerability (12 landmarks)
- See these lanes on the full map
How this project checks its facts · Report an error on this page