Low-dose Carbon Monoxide (HBI-002) Trial to Evaluate Safety, Tolerability, PK, and Biomarkers in Parkinson's Disease

Inclusion Criteria: Subjects must meet the following criteria before being enrolled into the study: 1. Signed informed consent. 2. Male or female 40-80 years of age 3. Non-smoker for at least 5 years with smoking defined as the use of smoked products (e.g. tobacco, marijuana, vaping or other) 4. No smoking in the home (i.e. not living with a smoker) 5. Body weight between 60 kg and 110 kg (inclusive) and with BMI less than 30 kg/m2 at screening and baseline 6. Diagnosis of PD according to the Movement Disorder Society within 60 months of screening 7. Hoehn and Yahr stage ≤ 3 8. PD therapy: use of ≥100 mg TID levodopa or equivalent dose with additional carbidopa/levodopa or other antiparkinsonian medication (e.g. dopamine agonists \[e.g., pramipexole, ropinirole, rotigotine\] and monoamine oxidase inhibitors \[e.g., selegiline or rasagiline\]) for ≥30 days of stable dosing 9. Good clinical response to levodopa therapy in the Site Investigator's opinion 10. Negative pregnancy test for females of childbearing potential 11. Where appropriate, subjects must be willing to use a highly effective method of contraception for the duration of the study and for 45 days thereafter 1. Male subjects, without a vasectomy, whose partner is of childbearing potential, must use a condom and be instructed that their female partner should use another form of contraception such as an IUD, diaphragm with spermicide, oral contraceptive, injectable progesterone, subdermal implant or a tubal ligation. Male subjects are prohibited from donating sperm for the duration of the study and 60 days following the end of study visit. 2. Female subjects of childbearing potential (not surgically sterilized and less than one year post-menopausal) should use a medically accepted form of contraception such as an IUD, diaphragm with spermicide, oral contraceptive, injectable progesterone, subdermal implant or a tubal ligation, and be instructed that their male partners should use a condom, if not vasectomized. 12. Subjects must be healthy as defined by the following. 1. liver function: alanine transaminase (ALT) and aspartate transaminase (AST) ≤ 2X ULN 2. total bilirubin ≤ 1.5X ULN 3. renal function: creatinine clearance within normal range as assessed by Cockcroft and Gault calculation 4. carboxyhemoglobin level by venous blood gas ≤ 3.5% 5. the absence of current clinically relevant abnormalities identified by a detailed medical history, full physical examination including blood pressure, pulse rate, and respiratory rate measurement, 12-lead ECG, and clinical laboratory tests (hematology and clinical chemistries), as determined by the Site Investigator. 6. HbA1c \< 6.5% 13. Subjects must have a study partner who can observe the subject for at least 4 hours after dosing at home (non-clinic days) in order to monitor for indications of CO toxicity. 14. Subjects should live within 100 miles driving distance (door to door) of the site/clinic due to the need to carry study drug and ship study drug between the site/clinic and subject's home. Exceptions to this may be considered with Sponsor approval if it can be assured that the subject can transport study drug from clinic to home within two hours. Exclusion Criteria: Subjects who meet any of the following criteria will be ineligible for participation in the study: 1. Clinical signs indicating a parkinsonian syndrome other than idiopathic PD, specifically: 1. Atypical parkinsonism, including parkinsonism due to drugs, metabolic disorders, encephalitis, cerebrovascular disease, normal pressure hydrocephalus, or other neurodegenerative disease. 2. Supranuclear gaze palsy 3. Signs of dementia (MoCA \< 22) 4. History of repeated strokes with stepwise progression of parkinsonian features 5. History of repeated head injury 6. History of definite encephalitis 7. Cerebellar signs 8. Early severe autonomic involvement 9. Babinski sign present 2. Dysphagia with liquids 3. History of exposure to or current treatment with neuroleptic drugs. 4. History of dementia 5. Oxygen saturation by transcutaneous measurement ≤ 95% confirmed on repeat assessment (any time prior to the first dose) 6. Clinically significant ECG abnormalities (prolonged QTc greater than normal range, arrhythmia detected, bradycardia \<45 bpm, tachycardia \>120 bpm, AV block \[second or greater degree\], bundle branch block) or vital sign abnormalities (systolic blood pressure lower than 90 or above 140 mm Hg, diastolic blood pressure lower than 50 or above 90 mm Hg, or heart rate less than 45 or above 100 bpm or arrhythmia), as determined by the Site Investigator. 7. Renal failure requiring renal replacement therapy 8. History of: 1. Serious cardiovascular diseases * History of angina pectoris * History of myocardial infarction or cardiac failure (NYHA from II to IV), myocardial insufficiency, symptomatic congestive heart failure with a documented ejection fraction below 45% * History of serious cardiac arrhythmia other than stable atrial fibrillation * History of stroke or occlusive peripheral vascular disease, brain vasospasm 2. Structural brain disease or cerebrovascular disease with clinical significance, including intracranial space-occupying lesion 3. Severe uncontrolled arterial hypertension 4. Severe pulmonary disease (asthma, COPD, other) 5. Specific psychiatric disorders, including hallucinations, delusions, pathologic gambling, alcohol or substance abuse or dependence 6. Type 1 or type 2 diabetes mellitus, impaired glucose tolerance, metabolic syndrome, maturity onset diabetes of the young, and gestational diabetes. 7. Pulmonary infiltrate or pneumonia within 6 months before screening or acute infection within 14 days of screening 8. Seizures / epilepsy 9. Autoimmune disease requiring prescribed immunomodulatory therapy 9. Alcohol abuse or dependence within one year prior to screening or regular use…

Reproduced word-for-word from the public registry record — the study team can answer questions about it.