The Safety and Tolerability Study With ER2001 Intravenous Injection in Adults With Early Manifest Huntington's Disease

Exclusion Criteria

• •1. History of attempted suicide or suicidal ideation with plan (i.e., active suicidal ideation) that required hospital visit and/or change in level of care within 12 months prior to screening.
• •2. Current active psychosis, confusional state, or violent behavior.
• •3. Bleeding tendency or history of coagulation disorder; As long as the investigator confirms that there is no evidence of bleeding tendency or coagulation dysfunction at present.
• •4. ECG with corrected QT interval (QTc) \> 480 ms and/or indication of uncontrolled cardiac conditions, as judged by the investigator (e.g. unstable ischemia, uncontrolled ventricular arrhythmia, recent (within 3 months) myocardial infarction,congestive heart failure, electrolyte disturbances, etc.)
• •5. Patients with HIV, Treponema pallidum, Hepatitis B, or Hepatitis C infection.
• •6. Need to take antiretroviral drugs, including antiretroviral drugs as preventive treatment.
• •7. Current or recurrent disease, infection, or other significant concurrent medical condition or medications that could confound clinical and laboratory evaluations or could affect a subject's safety or their ability to undergo the neurosurgical procedure or comply with the procedures and study visit schedule.
• •8. Clinical diagnosis of chronic migraines.
• •9. Presence of an implanted deep brain stimulation device, ventriculoperitoneal or other CSF shunt, or other implanted catheter.
• •10. Preexisting structural brain lesions (such as tumor, arteriovenous malformation) as assessed by a centrally read MRI scan during the screening period.
• •11. Any history of gene therapy, RNA or DNA investigational agents, such as antisense oligonucleotides (ASO), cell transplantation or any other experimental brain surgery.
• •12. Treatment with investigational therapy within 4 weeks prior to screening or 5 drug elimination half-lives of investigational therapy, whichever is longer.
• •13. Unable or unsafe to perform lumbar puncture on the patient.
• •14. In the Investigator's judgment, that Parkinson's disease, multiple system atrophy and other dystonia diseases may be combined.
• •15. Patients who are hypersensitive to any ingredients in the formulation of ER2001.
• •16. Malignancy within 5 years of screening, except for basal or squamous cell carcinoma of the skin or carcinoma in situ of the cervix that has been successfully treated.
• •17. Concurrent or planned concurrent participation in any interventional clinical study, including explicit pharmacological and non-pharmacological interventions. Observational studies are acceptable.
• •18. Any serious medical condition or clinically significant laboratory, vital signs, or abnormalities at screening that, in the Investigator's judgment, precludes the patient's safe participation in and completion of the study.