Previous studies have shown that the anterior cingulate cortex is involved in the regulation of pain and its associated negative emotions, that pyramidal neurons are highly excitable in chronic neuropathic pain conditions, and that silencing of pyramidal neurons can eliminate pain. The aim of this study was to evaluate the safety, tolerability, and efficacy of intracranial injection of GA (containing the hM4Di gene) in the anterior cingulate cortex in combination with oral clozapine for the treatment of refractory neuropathic pain.
Regularised treatment with conventional medical therapy (including, but not limited to, medication, physiotherapy, cognitive therapy, nerve blocks and other non-invasive or minimally invasive treatments) for at least 3 months with no symptomatic relief or emergence of tolerance, as assessed by the investigator
Pharmacological treatment means a full course of treatment with at least two first-line medications, as assessed by the investigator
Mean visual analogue scale (VAS) value ≥4 cm and/or mean numerical rating scale (NRS) value ≥4 points within one week of baseline at enrolment
Subjects who have had a stable analgesic regimen for at least 30 days prior to the intensity of pain described in Inclusion Criterion 2 and agree not to arbitrarily change the type and dose of medication that they are currently taking until the end of the period of assessment of the effectiveness of this trial, as assessed by the investigator
suffering from severe cardiopulmonary disease such as unstable angina, myocardial infarction, severe arrhythmia, recurrent asthma attacks, etc;
white blood cell count <3.5 x 109/L and neutrophil count <1.0 x 109/L
Platelet (PLT) <75 x 109/L
Coagulation: prothrombin time and activated partial thromboplastin time >1.5 x ULN