Antibody Targeting a Sugar-Binding Immune Protein Advances to Phase 2 in Parkinson's Disease

TrueBinding's TB006, an antibody against galectin-3, has entered a placebo-controlled Phase 2a trial in early Parkinson's disease, according to its federal registration. The approach targets neuroinflammation rather than the alpha-synuclein clumping or kinase pathways most late-stage Parkinson's drugs pursue, and no human efficacy data in Parkinson's disease exist yet.

A Phase 2a, randomized, double-blind, placebo-controlled trial of TB006, an antibody made by TrueBinding, Inc. that targets a sugar-binding immune protein called galectin-3, is underway in people with early Parkinson's disease, according to the study's registration on ClinicalTrials.gov (NCT06773962). The trial enrolled an estimated 62 participants, ages 50 to 80, diagnosed with Parkinson's disease for less than five years and already taking levodopa-based medication, at sites across the United States. It is listed as active but no longer recruiting, having started in March 2025, with a primary completion date estimated for November 2026. TrueBinding's own website states that enrollment for the study is complete.

Galectin-3 is a protein expressed by activated microglia, the brain's resident immune cells, and researchers have linked it to inflammation and to protein aggregation in several neurodegenerative conditions. TrueBinding, which received FDA clearance to test TB006 in Parkinson's disease in November 2024, describes the monthly intravenous antibody as designed to neutralize galectin-3 in ways the company says may help break up harmful protein clumps, including those involving alpha-synuclein, and calm inflammatory activity in the brain, according to the company's own announcement of that clearance. Those mechanistic claims come from the company and from preclinical studies; they have not been demonstrated in a completed, peer-reviewed human Parkinson's trial.

The trial's stated objectives are to assess TB006's effect on motor function and its safety in Parkinson's disease, per the study registration. That puts it apart from most of the current late-stage Parkinson's pipeline, which largely targets alpha-synuclein aggregation directly or inhibits kinase enzymes such as LRRK2. TB006 was first given to humans in a 2021 dose-escalation study of 48 healthy volunteers, which found single doses up to 5,000 milligrams were generally well tolerated, according to a summary maintained by the Alzheimer's research site Alzforum. The company has also reported, in a press statement rather than a published paper, a "positive trend" toward cognitive improvement in a small, earlier proof-of-concept trial of TB006 in Alzheimer's disease.

Whether neutralizing galectin-3 changes the course of Parkinson's disease in people, or merely proves safe to give, remains unanswered. The trial's estimated primary completion date is not until November 2026, and no interim results have been posted to the registry as of this writing.

Families and clinicians watching this trial will not have an answer to whether the drug helps until the study's primary completion date, and even then, a single 62-person Phase 2a trial cannot establish whether a treatment works; larger, later-stage trials would be needed for that.