Efficacy and Safety Study of Thioctacid Oral Tablets 600mg to Treat Chinese Diabetic Patients With Distal Symmetric Polyneuropathy

Study Overview
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Brief Summary
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The purpose of the study is to evaluate the efficacy on overall neuropathic sensory symptom improvement of Thioctacid tablet 600mg once daily vs. placebo in 6-weeks' treatment in Chinese diabetic patients with distal symmetric polyneuropathy (DSP).

Official Title
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Randomized, Double-Blind, Placebo-Controlled, Parallel Group, Multicenter Study to Evaluate the Efficacy and Safety of Thioctacid Oral Tablet 600mg Once Daily in Chinese Diabetic Patients With Distal Symmetric Polyneuropathy

Conditions
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Diabetics

Intervention / Treatment
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* Drug: lipoic acid
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects must fulfil all of the following criteria to be appropriate to enter into Registry (Visit 2) Provision of informed consent Females and males aged from 18 to 75 (inclusive), who were definitely diagnosed with diabetes HbA1C< 10％ Moderate neuropathy according to Neuropathy Disability Score (NDS) >= 4 points. Difference in score between left and right foot is not to be higher than 2 points Total Symptom Score (TSS) > 6.5 points At least one of the four symptoms of the TSS has occurred continuously over the last 3 months before screening Other concomitant treatments (the drugs and their dosage) have been stable over 1 month before screening Subjects must fulfil all of the following criteria before randomization： TSS > 5 points TSS range (maximum TSS - minimum TSS during Run-in Period) < 3 points during the Run-in Period Compliance in Run-in Period > 85% Exclusion Criteria: Neurologic disease other than diabetic neuropathy that may produce weakness, sensory loss, or autonomic symptoms or test abnormality Peripheral vascular disease severe enough to cause intermittent claudication or ischemic ulcers Patients who have been hospitalized due to glucopenia or ketoacidosis in the last 3 month Present ulcers on lower limbs of any cause Antioxidant therapy within the last 1 month before screening (Vitamin E> 400IU, Vitamin C> 200mg once daily for continuous 2 weeks) Any ALA therapy within the last1 month before screening Opioid analgesic therapy within the last 1 month before screening History of mental, psychological or behavioral conditions rendering the patient unable to follow the protocol History of malignant tumors in the past 5 years except for basal cell carcinoma Any severe systematic diseases, at the investigator's discretion, which will make it undesirable for the patient to participate in the trial or which could jeopardize compliance with the trial protocol, ALT or AST > 2.5 ´ upper limit of reference range Cr > 1.8mg/dL ( > 159µmol/L) for males or > 1.6mg/dL ( > 141µmol/L) for females History of hypersensitive to the active ingredients or excipients of ALA Participation in a clinical study or treatment with a non-approved experimental medication in the last 1 month Pregnant or breast-feeding women, or women of childbearing age without appropriate contraception measures

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Thioctacid Oral Placebo Tablet<br> | Other: Placebo<br>* Tablet, placebo, 1-week single-blind placebo treatment then, 30 min before breakfast, once daily for 6 weeks<br>|
| Active Comparator: Thioctacid Oral Tablet<br> | Drug: lipoic acid<br>* Tablet, 600mg, for oral use, 30 min before breakfast, once daily for 6 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To evaluate the efficacy on overall neuropathic sensory symptom improvement of Thioctacid tablet 600mg once daily vs. placebo in 6-weeks' treatment in Chinese diabetic patients with distal symmetric polyneuropathy (DSP) | Changes from baseline in Total Symptom Score (TSS) from week 1 to week 6 will be computed and summarized in an Area Under the Curve (AUC). | 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To evaluate each sensory symptom improvement of Thioctacid tablet 600mg once daily vs. placebo in 6-weeks' treatment in Chinese diabetic patients with DSP | Changes in the individual symptom scores of the TSS (Stabbing pain, burning, paraesthesia, numbness) | 6 weeks | 
| To evaluate onset time of Thioctacid tablet 600mg once daily vs. placebo in 6-weeks' treatment in Chinese diabetic patients with DSP |  | 6 weeks | 
| To evaluate response rate of Thioctacid tablet 600mg once daily vs. placebo in 6-weeks' treatment in Chinese diabetic patients with DSP |  | 6 weeks | 
| To evaluate the tolerability and safety of Thioctacid tablet 600mg once daily vs. placebo in 6-weeks' treatment in Chinese diabetic patients with DSP | Number of adverse events and standard laboratory tests will be the Measures of Safety and Tolerability | 6 weeks |