From Poison to Promise: Can Low-Dose Carbon Monoxide Halt Parkinson's?

SAN DIEGO, CA – June 15, 2026

A San Diego-based biotech has just begun a clinical trial for a Parkinson's therapy based on a molecule most people associate with danger: carbon monoxide. Hillhurst Biopharmaceuticals announced today it has dosed its first patient in a Phase 2a trial for HBI-002, an oral drug that could represent a paradigm shift in treating the neurodegenerative disease. The move, backed by prestigious foundations, pivots on a fascinating scientific paradox and a novel technology platform that could turn a well-known poison into a potential protector of the brain.

The Science of a Paradox

The journey of HBI-002 begins with a decades-old, counterintuitive observation from epidemiology: cigarette smokers have a consistently lower risk—up to 60%—of developing Parkinson's disease. While the devastating health consequences of smoking are undisputed and overwhelming, scientists have long been intrigued by this statistical anomaly, hypothesizing that a single component within the toxic cocktail of smoke might hold a neuroprotective key.

Hillhurst Bio's research zeroes in on carbon monoxide (CO). While lethal in high concentrations, researchers now understand that the body produces its own small amounts of CO, which acts as a crucial signaling molecule. At carefully controlled, low therapeutic doses, exogenous CO has demonstrated powerful anti-inflammatory, anti-apoptotic (preventing cell death), and cytoprotective properties.

The company's approach, supported by preclinical studies, suggests that low-dose CO may combat Parkinson's on a fundamental level. In rodent models of the disease, treatment with HBI-002 was shown to protect the vital dopaminergic neurons that are progressively lost in Parkinson's patients. These are the neurons responsible for producing dopamine, a neurotransmitter critical for motor control. Furthermore, the preclinical data indicated that the therapy helped reduce the accumulation of alpha-synuclein, the misfolded protein that forms toxic clumps in the brains of patients and is a hallmark of the disease. The therapy appears to work by activating a protective cellular pathway mediated by an enzyme called heme oxygenase-1 (HO-1), which helps the brain manage oxidative stress and clear out damaging proteins.

It is a line of inquiry that requires delicate communication. Hillhurst is adamant, as are its research partners, that this work in no way mitigates the known dangers of smoking. Instead, it represents an effort to isolate a potentially beneficial mechanism and deliver it safely and precisely, divorced from the thousands of other harmful compounds found in tobacco smoke.

Targeting a Formidable Foe

The initiation of this trial is a significant event for the approximately 1.1 million people in the United States living with Parkinson's disease. For decades, the standard of care has revolved around managing symptoms, not halting the disease itself. The most common treatment, levodopa, works by replenishing the brain's dwindling supply of dopamine, helping to control tremors, stiffness, and slowness of movement.

However, these treatments are not a cure. They do not stop the underlying neurodegeneration, and their effectiveness can wane over time, often leading to debilitating side effects and motor complications. This leaves a vast and urgent unmet medical need for what are known as Disease-Modifying Therapies (DMTs)—treatments that can slow, stop, or even reverse the progression of the disease. The pipeline for such therapies is active, but a breakthrough has remained elusive.

HBI-002 enters this landscape as a novel contender. By targeting the underlying biology of inflammation and cell death, it aims to be more than just a symptomatic treatment. If successful, it could offer patients a way to preserve neurological function for longer, fundamentally changing the prognosis for a disease that currently has none. The drug's oral liquid formulation is also a key feature, designed for chronic, at-home use, which would dramatically improve convenience and accessibility for patients compared to more invasive therapies.

The Business of Innovation: Hillhurst's GLASS Platform

The story of HBI-002 is also the story of Hillhurst Bio's core innovation: its proprietary "Medical Gas in Liquid Advanced Stability System," or GLASS™ platform. This technology is the engine behind the company's entire strategy and represents a fascinating intersection of chemistry, engineering, and medicine.

Historically, therapeutic gases like carbon monoxide or nitric oxide have been administered via inhalation. This method can be imprecise, difficult for conscious patients, and poses potential risks of environmental exposure. The GLASS™ platform cleverly sidesteps these issues by enabling the stable suspension of these gases in a liquid form, allowing for precise, oral dosing. The therapeutic gas is released in the gastrointestinal tract and absorbed into the bloodstream, reaching its target tissues without the need for cumbersome tanks or masks.

This platform technology is the cornerstone of Hillhurst's business model. While HBI-002 for Parkinson's is a flagship program, it's just one application of a much broader concept. The company is simultaneously advancing HBI-002 in a Phase 2a trial for sickle cell disease, another condition where CO's anti-inflammatory and vaso-relaxant properties could be beneficial. Further preclinical work is underway for diabetic retinopathy and preventing cardiotoxicity from chemotherapy. This multi-pronged approach diversifies risk and showcases the platform's potential to generate a pipeline of novel drugs from known therapeutic agents, a highly efficient strategy in the capital-intensive world of biopharma.

The Credibility of Collaboration

In the high-stakes world of biotechnology, a promising idea is not enough. The backing of major, credible partners is often the deciding factor in whether a novel therapy can make the leap from the lab to the clinic. Hillhurst's HBI-002 trial is bolstered by significant support from two key foundations.

The Michael J. Fox Foundation for Parkinson's Research (MJFF) contributed a $2 million grant through its Therapeutics Pipeline Program. This is more than just funding; it's a powerful endorsement. MJFF is the world's largest nonprofit funder of Parkinson's research, known for its rigorous scientific vetting and its laser focus on accelerating treatments with the potential for tangible patient impact. Their support signals that HBI-002 has cleared a high bar for scientific merit and potential to address an unmet need.

The trial also received a substantial $4.3 million from the Farmer Family Foundation, in conjunction with Massachusetts General Hospital, where some of the foundational research was conducted by Dr. Stephen Gomperts, a neurologist and brother of Hillhurst CEO Andrew Gomperts. This combination of mission-driven non-profit funding and private philanthropy provides the financial runway necessary for the complex and expensive process of clinical development.

"Dosing the first subject in this study marks a significant milestone," said Chief Executive Officer Andrew Gomperts in a statement. "There remains a substantial unmet medical need for therapies that address the underlying patho-biology of Parkinson's disease, and we are hopeful that our novel drug product can provide benefits to patients."

The Phase 2a trial is a blinded, randomized, and controlled study focused primarily on establishing the safety and tolerability of HBI-002 in people with Parkinson's. However, it will also collect crucial biomarker and pharmacokinetic data that could provide the first hints of the drug's efficacy in humans. With the first data readout expected by the end of 2026, the entire Parkinson's community—patients, researchers, and clinicians—will be watching closely. This trial is a pivotal step, and its outcome will inform the design of a larger Phase 2b study planned for 2027, moving one step closer to potentially turning a scientific paradox into a powerful new medicine.