Parkinson's Disease Treatment Pipeline

As of July 2026, the Parkinson's disease treatment pipeline includes tavapadon (FDA decision expected in Q3 2026), prasinezumab in Phase 3 (anti-alpha-synuclein antibody), bemdaneprocel in Phase 3 (stem cell therapy), and AB-1005 in Phase 2 (GDNF gene therapy). No disease-modifying therapy has yet been approved. Two disease-modifying candidates read out negative Phase 2 results in the first half of 2026 — the LRRK2 inhibitor BIIB122 and the GCase modulator BIA 28-6156 — and were discontinued for Parkinson's, a reminder that most candidates in trials do not succeed.

This page tracks the most significant drugs and therapies currently in clinical development for Parkinson's disease. It is organized by development phase and therapeutic category. We update this tracker as new data are published, trials reach milestones, and regulatory decisions are made. The most recent update reflects data available through July 2026.

Important: All therapies listed below as “investigational” are not yet proven safe or effective for Parkinson's disease. They are under study in clinical trials and are not available for routine use outside of those trials. Inclusion on this list does not constitute an endorsement or prediction of success.

Pending FDA Decisions

Tavapadon

Tavapadon is a novel oral, once-daily dopamine receptor agonist that selectively targets D1 and D5 receptors. This distinguishes it from existing dopamine agonists (pramipexole, ropinirole, rotigotine), which primarily target D2 and D3 receptors. AbbVie submitted a New Drug Application (NDA) to the FDA on September 26, 2025, based on positive results from the Phase 3 TEMPO clinical trial program.

The TEMPO trials demonstrated statistically significant improvements on the MDS-UPDRS scale, increased “on” time without troublesome dyskinesia in patients with motor fluctuations, and a favorable long-term safety profile. If approved, tavapadon would be the first new oral dopamine agonist approved for Parkinson's disease in over a decade.

Recently Approved (2024-2025)

Phase 3 Clinical Trials

Phase 3 trials are large-scale studies (typically hundreds to thousands of participants) designed to confirm efficacy and safety. Success in Phase 3 is required for FDA approval.

Prasinezumab (Roche/Genentech) — Anti-Alpha-Synuclein Antibody

Prasinezumab is a monoclonal antibody designed to bind and clear aggregated forms of alpha-synuclein — the protein that forms toxic Lewy bodies in Parkinson's disease. It represents the most advanced attempt at disease modification through immunotherapy.

• Phase IIb PADOVA results (June 2025): In 586 participants treated for 18+ months, the trial narrowly missed its primary endpoint of time to confirmed motor progression (hazard ratio 0.84, p=0.0657). However, a pre-specified subgroup of patients already on levodopa showed a significant reduction in motor progression risk (HR=0.79, p=0.04). Safety was favorable with no new safety signals across 900+ participants.
• Phase 3 PARAISO initiated November 2025: about 900 participants, 2-year treatment period, with primary completion expected in June 2029.
• Significance: If successful, prasinezumab would be the first therapy proven to slow the underlying progression of Parkinson's disease — a fundamental advance in treatment.

Bemdaneprocel (BlueRock/Bayer) — Stem Cell Therapy

Bemdaneprocel is the most advanced stem cell therapy for Parkinson's disease. It consists of dopamine-producing neurons derived from human embryonic stem cells, surgically implanted into the brain to replace neurons lost to the disease.

• Phase 3 exPDite-2 trial: First patient treated September 2025. This is the first large-scale global cell therapy trial for Parkinson's disease.
• Significance: If successful, cell replacement could fundamentally change the treatment of Parkinson's disease by restoring dopamine production rather than merely supplementing it with medication.

Solengepras (Cerevance) — Non-Dopaminergic Adjunctive

• ARISE Phase 3 trial: Evaluating solengepras (formerly CVN424, a GPR6 inhibitor) as an adjunctive treatment for motor fluctuations in Parkinson's disease. Cerevance completed enrollment (about 341 participants) in May 2026.
• Data expected: End of Q3 2026.

Phase 2 Clinical Trials

Phase 2 trials test efficacy in a smaller group of patients and optimize dosing. Positive Phase 2 results can lead to Phase 3 trials, but many drugs that show promise in Phase 2 fail in Phase 3.

AB-1005 — GDNF Gene Therapy

AB-1005 uses an AAV2 viral vector to deliver the gene for glial cell line-derived neurotrophic factor (GDNF) directly to the brain. GDNF is a growth factor that supports dopaminergic neuron survival.

• Phase 2 REGENERATE-PD trial: An international trial across sites in Germany, Poland, the United Kingdom, and the United States.
• FDA RMAT designation: Granted February 2025 (Regenerative Medicine Advanced Therapy), an expedited regulatory pathway.
• Status: Still enrolling (randomization began in Europe in late 2025). Per ClinicalTrials.gov, estimated primary completion is 2028; AskBio has not disclosed a topline data date.
• Significance: One of the most advanced gene therapy programs for PD. GDNF has shown neurotrophic potential in preclinical models for decades; AB-1005 represents the most rigorous clinical test to date.

BIIB122 — LRRK2 Inhibitor (Phase 2b failed, 2026)

BIIB122 (Biogen/Denali) targeted the LRRK2 protein, which is overactive in both genetic LRRK2-related Parkinson's disease and a proportion of sporadic PD.

• LUMA trial (Phase 2b, ~648 participants): In May 2026, Biogen and Denali reported that LUMA did not meet its primary endpoint — BIIB122 did not slow disease progression. The companies discontinued development of BIIB122 in idiopathic Parkinson's disease.
• What continues: A separate Phase 2a study (BEACON) in people who carry a LRRK2 genetic variant is ongoing, with results expected in the first half of 2027.

BIA 28-6156 — GCase Modulator for GBA1-PD (Phase 2b failed, 2026)

• ACTIVATE trial (Phase 2b, 273 participants): Tested BIA 28-6156 (Bial) in patients with GBA1 mutations, which are found in roughly 10 to 15 percent of PD cases. In June 2026, the trial did not meet its primary or key secondary endpoints, and Bial discontinued development for this indication.

GT-02287 — GCase Activator

• Phase 1b extension study: Evaluating a glucocerebrosidase (GCase) activator.
• Data expected: September 2026.

Disease-Modifying Approaches by Category

Alpha-Synuclein-Targeted Therapies

Alpha-synuclein aggregation is the pathological hallmark of Parkinson's disease. Multiple approaches aim to reduce, clear, or prevent the toxic protein accumulation:

• Antibodies (immunotherapy): Prasinezumab (Phase 3) is the most advanced. Cinpanemab (Biogen) was discontinued after a negative Phase 2 trial in 2022. Lu AF82422 (Lundbeck) completed Phase 1.
• Antisense oligonucleotides (ASOs): ASOs targeting SNCA (the alpha-synuclein gene) aim to reduce production of the protein at its source. Preclinical data show prevention and reversal of pathology. Early human safety data are emerging.
• Small molecule inhibitors: Several companies are developing small molecules that prevent alpha-synuclein aggregation. These are mostly in preclinical or early Phase 1 stages.

GLP-1 Receptor Agonists

GLP-1 receptor agonists — originally developed for type 2 diabetes — have been investigated for possible neuroprotective effects in Parkinson's disease. The results have been mixed:

• Lixisenatide (LIXIPARK trial, Phase 2): Showed modest reduction in motor disability progression over 12 months. The most positive result among GLP-1 agonists tested in PD. Significant GI side effects (46% nausea).
• Exenatide (Phase 3): Failed to meet significant efficacy endpoints (Lancet, 2025). Two trials total, neither showing clear benefit.
• Overall status: Six published trials of four GLP-1 agonists; only lixisenatide showed superiority to placebo. The Parkinson's Foundation explicitly states that GLP-1 drugs like Ozempic are NOT proven treatments for PD and should not be used outside research settings.

Gene Therapy

• AB-1005 (GDNF): Phase 2, still enrolling; estimated primary completion 2028 (see above).
• VGN-R09b (AADC + GDNF): Dual-mechanism gene therapy combining dopamine synthesis enzyme delivery with neuroprotection. Phase 1, first dose group completed.
• GBA gene correction: First trial using gene therapy to correct the GBA mutation, a genetic cause of PD. Early-phase clinical trial.

Cell Replacement Therapy

• Bemdaneprocel (BlueRock/Bayer): Phase 3, first patient treated September 2025 (see above).
• Autologous iPSC therapies (Mass General Brigham): Phase 1 using patient's own reprogrammed stem cells to replace dopamine neurons. Three patients treated.
• UX-DA001: iPSC-derived autologous cell therapy. Positive efficacy data from first patient presented at 2025 MDS Congress.
• Korean hESC-derived therapy: Phase 1/2a, 12 patients received bilateral putamen transplantation of high-purity dopaminergic progenitors. Results published in Cell (2025).
• RNDP-001 (Kenai Therapeutics): Phase 1, initial data expected 2026.

Upcoming Trial Milestones

Early-Stage Research to Watch

NLRP3 Inflammasome Inhibition

Dapansutrile, an NLRP3 inflammasome inhibitor, is entering a Phase 2 trial (DAPA-PD) for Parkinson's disease. The NLRP3 inflammasome is a key mediator of neuroinflammation, which plays an increasingly recognized role in PD progression. Recruitment expected early 2026.

Michael J. Fox Foundation Targets to Therapies Initiative

In December 2025 and January 2026, the MJFF awarded 142 new research grants totaling $101 million. The Targets to Therapies (T2T) Initiative represents the foundation's first target validation efforts for several novel biological targets: NOD2 (an immune receptor), OGA (an enzyme involved in protein modification), and endolysosomal mechanisms including TRPML1, TMEM175, and ATP13A2. These early-stage programs may yield drug candidates within 3 to 5 years.

SLEIPNIR Clinical Trial Platform

Funded by Cure Parkinson's (UK), SLEIPNIR is a multi-arm clinical trial platform designed for rapid assessment of potential disease-modifying drugs. The platform format allows multiple drugs to be tested simultaneously against a shared placebo arm, reducing the time and cost needed to evaluate each candidate. Recruitment is expected to begin in 2026.

Understanding Clinical Trial Phases

For patients and families following the research pipeline, understanding what each phase means helps set realistic expectations:

• Phase 1: Tests safety and dosing in a small number of participants (20-80). The primary question is: Is this safe? Success rate proceeding to Phase 2: approximately 60-70%.
• Phase 2: Tests efficacy in a larger group (100-300). The primary question is: Does this work? Success rate proceeding to Phase 3: approximately 30-40%.
• Phase 3: Confirms efficacy and safety in a large population (300-3,000+). The primary question is: Is this effective and safe enough for FDA approval? Success rate for approval: approximately 50-60%.
• FDA Review: After successful Phase 3, the sponsor submits an NDA or BLA to the FDA. Review typically takes 10 to 12 months.

Overall, the probability that a drug entering Phase 1 clinical trials will ultimately receive FDA approval is approximately 10 to 15 percent. For neurological diseases, the rate is historically even lower. This context is important for maintaining realistic expectations while remaining informed and hopeful.

How to Participate in Clinical Trials

Clinical trials rely on volunteers, and participation is one of the most direct ways to contribute to advancing Parkinson's disease treatment. Resources for finding trials include:

• Fox Trial Finder (foxtrialfinder.michaeljfox.org) — The Michael J. Fox Foundation's matching service pairs your profile with currently recruiting trials.
• ClinicalTrials.gov — The U.S. government registry of all clinical trials. Search for “Parkinson's disease” and filter by location, status (recruiting), and phase.
• Your movement disorder specialist — Specialists at academic medical centers and Centers of Excellence often have direct connections to ongoing trials and can advise whether you may be a good candidate.
• Parkinson's Foundation Helpline — 1-800-4PD-INFO (1-800-473-4636). Specialists can help you understand clinical trial options.

This pipeline tracker is updated as milestones are reached. Last updated: July 2026. If you are aware of a significant trial milestone or result that is not reflected here, please contact us through our corrections page.