Part 4 · Living, caring, preventing
Toward a cure
Many trials are testing ways to slow Parkinson's, and none has yet been proven to. A ten-year review of the drug pipeline concludes that "there are still no treatments to modify the course of the disease". 47 This page reports the research routes as research, with an evidence label on each, and states negative results as plainly as positive ones.
How the labels are used here. Established means shown, positive or negative, in at least one adequately powered randomised controlled trial. Early evidence means some randomised or controlled signal, or consistent open-label and biomarker data, not confirmed in phase 3. Hypothesis means a mechanistic, laboratory or observational rationale, or only safety and target-engagement data in people. By this scheme no route has established disease-modifying benefit. 47,72
Where could treatment intervene?
Schematic, not to scale. The flow beyond the marker is a picture of the trial result, not a measurement.
The routes, trial by trial
Each card gives the mechanism step, then the key trials with their registry number, phase, size and primary result. Registry statuses are as listed on ClinicalTrials.gov on 20 October 2026. 72
Trial timeline
Each dot is a trial result by year of publication or report; hollow dots are trials still running, placed at their estimated primary completion. Filter by route or by result, drag the years, or tap a dot.
Years are publication or report years; running trials sit at the registry's estimated primary completion. Not every trial in the field is shown.
The pipeline in numbers
Shares of trials from the annual pipeline reviews of ClinicalTrials.gov.
No 2025 update of this pipeline series was found; the ten-year analysis published in 2026 is the most recent review in the series. 47
How trials try to tell slowing from masking
Parkinson's medicines improve symptoms, so a drug that simply adds a little symptomatic benefit can look like one that slows the disease. A delayed-start design is one answer. Switch between the two possibilities and play the trial.
Schematic. No real trial data are drawn; the lines show the logic of the design only.
Washout and off-medication scores
Medicines taken during a trial can mask progression. The exenatide trial added a 12-week washout and LIXIPARK a 2-month one; PADOVA used time to confirmed worsening on OFF-medication scores. 20,228,244
Subgroups and external comparisons
A post hoc PASADENA analysis found larger effects in faster-progressing subgroups, which its authors say needs new randomised trials. 267 The open-label extension compared participants with an outside cohort (PPMI), which is exploratory and not randomised. 268
Seed amplification assays
The US FDA issued a Letter of Support for the CSF alpha-synuclein seed amplification assay as a susceptibility and risk biomarker, so trials can enrol people who have underlying synuclein pathology. 344 See Diagnosis and the MDS criteria.
Many drugs, one trial
Path to Prevention is a phase 2A, multi-regimen platform trial nested in the PPMI cohort, for early-stage neuronal alpha-synuclein disease; no registry number or named drugs were found. 338 EJS ACT-PD is a multi-arm phase 3 platform testing terazosin and telmisartan against placebo in an estimated 1,200 people. 72
Unproven stem-cell clinics
What the guidelines say. The International Society for Stem Cell Research says stem-cell-based interventions must be "proven safe and effective" before they are marketed to patients, and cautions that registration on a trials website does not mean a study has been vetted. 159
What Japan's approval is, and is not. In early March 2026 Japan granted conditional, time-limited approval to an iPS-cell-derived product on the basis of a 7-patient trial, with 7 years to collect confirmatory data and validity only within Japan. Patient organisations note open questions on long-term safety, rejection and how long grafts last. 276,315
Two synuclein antibodies, an LRRK2 kinase inhibitor and two GBA1-pathway drugs missed their primary endpoints in randomised trials. 125,185,229,239,244,266 Two small GLP-1 trials were positive on motor scores, but a phase 3 trial, now under an Expression of Concern, and another phase 2 trial were negative. 20,222,228,362 A phase 3 antibody trial, a phase 3 cell trial and a phase 3 exercise trial are running. 72,341 See Genes and inheritance and Living with Parkinson's.