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Assessment of Efficacy and Safety of Thioctic Acid in the Oral Treatment of Diabetic Polyneuropathy (Stage 1 or 2)

Phase 3
Completed
Conditions
Diabetic Polyneuropathy
Interventions
Drug: Placebo
Registration Number
NCT00977483
Lead Sponsor
MEDA Pharma GmbH & Co. KG
Brief Summary

To assess clinical efficacy and safety of long-term orally administered thioctic acid in the treatment of diabetic polyneuropathy.

Detailed Description

Stage 1 or 2a diabetic (poly)neuropathy (DNP) (Appendix 3) in patients with diabetes mellitus (type I or II); neuropathy impairment score of the lower limbs, enlarged by 7 objective items (NISLL+7) ≥ 97.5 percentile (corresponding to 4.43 score points); total symptoms score of the feet (TSSfeet) ≤ 5.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
460
Inclusion Criteria
  1. Signed Informed Consent. Patients must have willingness and complete competence to cooperate and language barriers must not preclude adequate understanding

  2. Diabetes mellitus (Type I or II), as defined by the American Diabetes Association 1997, lasting > 1 year

  3. Males or females 18 to 64 years (older patients are excluded because of age-related changes in reflexes, quantitative sensory testing endpoints, and nerve conduction endpoints)

  4. Patient must have a symmetric sensory-motor peripheral polyneuropathy attributable to diabetes mellitus following a thorough evaluation for other causes of neuropathy determined by performing complete medical and neurological examinations including physical and neurological history, history of medications, history of exposure to other toxins, and laboratory studies

  5. Severity of diabetic polyneuropathy must be Stage 1 or 2a

  6. Insulin regimen, weight, diet, and activity level must be relatively stable in the opinion of the investigator (for example, HbA1C must not vary by more than ± 2 Vol.% within 6 months preceding the study i.e. if the index measure = 10% the range would be 8-12%)

  7. NIS[LL]+7 tests ≥ 97.5 percentiles (corresponding to 4.43 transformed score points)

  8. NIS[LL] ≥ 2 points (NIS[LL] is based on questions 17-24, 28, 29, 34, 35, and 37 of the NIS)

  9. One of the following:

    • an abnormality of nerve conduction attributes in two separate nerves, i.e. ≥99th percentile for DL or ≤1st percentile for NCV or amplitude or
    • an abnormality of HRDB, i.e. ≤ 1st percentile
  10. TSS (feet) ≤5

  11. Females must either be surgically sterilised (tubal ligation, bilateral oophorectomy, or hysterectomy) or at least 1 year postmenopausal or practicing an acceptable method of contraception, including oral contraceptives with a stable regimen for at least two months, depo-medroxyprogesterone, a barrier method alone (diaphragm, condoms, or contraceptive sponge with spermicidals), or an IUD that has been in place for at least two months

Exclusion Criteria
  1. Patients with proximal asymmetric neuropathy, cranial neuropathies, truncal radiculopathy, pan dysautonomia, diabetic plexopathies, or acute or active mononeuropathies (including cranial neuropathies, post-herpetic neuralgias, etc.), the presence of which might obscure accurate assessment of severity of the diabetic polyneuropathy under assessment, with the exception of carpal tunnel syndrome (CTS) or tardy ulnar neuropathy (TUN) or both
  2. Neuropathy of any cause other than diabetes mellitus which might interfere with the assessment of the severity of dPNP Other neurologic diseases that may produce weakness, sensory loss, or autonomic symptoms or test abnormality which might interfere with the assessment of the severity of dPNP Myopathy of any cause which might interfere with the assessment of the severity of dPNP
  3. Peripheral vascular disease severe enough to cause intermittent claudication or ischemic ulcers or limb ischemia
  4. Patients with a history of ophthalmological findings suggesting a high risk for visual loss i.e., significant maculopathy or proliferative retinopathy
  5. Psychiatric, psychological, or behavioural symptoms that would interfere with the patient's ability to participate in the trial
  6. Patients with any active neoplastic disease except basal cell carcinoma
  7. Patients with atrial fibrillation unless controlled and stabilised by medication (changed to this criterion by Amendment 1)
  8. Patients with clinically significant cardiac, pulmonary, gastrointestinal, hematologic, or endocrine disease (other than diabetes) that may confound interpretation of the study results or prevent the patient from completing the study
  9. Patients who have had organ transplants of any kind
  10. Patients with significant hepatic or renal disease (ASAT or ALAT >2 times normal, serum creatinine >1.8 mg/dL (>159 µmol/l) for males or >1.6 mg/dL (>141 µmol/l) for females)
  11. Patients with a recent history (within last 12 months) of drug or alcohol abuse
  12. Use of any investigational drug within the last 6 months
  13. History of severe or anaphylactic reaction to multiple drugs, sulfur products, or biologic products (changed to this criterion by Amendment 1)
  14. Ketoacidosis or hypoglycaemia within last 3 months resulting in hospital admission
  15. Antioxidant therapy (vitamins E > 400IU, C > 200mg, and beta-Carotene > 30mg) or pentoxyphylline within last 1 month before start of trial
  16. Use of evening primrose oil or any other gamma-linolenic acid containing substance within the last 3 months
  17. Use of thioctic acid > 50mg/day within last 3 months
  18. History of use of medications or vitamins known to cause peripheral neuropathy including but not limited to use of phenytoin or carbamazepine over 15 or more years, or use of pyridoxine > 100mg/d within the past 12 months
  19. Bilateral sural nerve biopsies
  20. Existing foot ulcers
  21. Pregnant or lactating females
  22. Continued use of medications listed in protocol 6.3.3 (first paragraph)
  23. Medication non-compliance (deviation of more than ±10% of dosages to be taken (1 tablet/day))

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Drug: PlaceboPlacebo1 tablet once daily throughout the trial
Drug: Thioctic AcidThioctic Acid600mg tablet Thioctic Acid (alpha-lipoic acid) once daily throughout the trial
Primary Outcome Measures
NameTimeMethod
Primary efficacy variable: Absolute change in the neuropathy impairment score lower limbs enlarged by 7 objective items (NISLL+7) between baseline (mean of Visit 0.3 and 0.4 or last available value before randomisation, respectively) and endpoint4 years
Secondary Outcome Measures
NameTimeMethod
NIS, NSC, TSS, LLF, QST, VDT, CDT and HP, QAE by means of the HRDB, amplitude CMAP, DL and MNCV on peroneal and tibial nerves, amplitude SNAP and latency on sural nerve, foot inspection, efficacy.4 years

Trial Locations

Locations (38)

Mayo Clinic Arizona

🇺🇸

Scottsdale, Arizona, United States

University Hospital Utrecht Department of Internal Medicine

🇳🇱

Utrecht, Netherlands

Loyola University Medical Center

🇺🇸

Maywood, Illinois, United States

Dallas Diabetes & Endocrine Center

🇺🇸

Dallas, Texas, United States

UCSD Neuromuscular Research Program

🇺🇸

San Diego, California, United States

Health Partners Riverside Neurology Clinic

🇺🇸

Minneapolis, Minnesota, United States

Hospital Clinico y Provincial

🇪🇸

Barcelona, Spain

C.H.U.S. General Hospital

🇪🇸

Santiago de Compostela, Spain

University Clinic

🇸🇪

Malmö, Sweden

Creighton University Diabetes Center

🇺🇸

Omaha, Nebraska, United States

´Diabetes Care Center

🇺🇸

Birmingham, Alabama, United States

Diabetes Research Center

🇺🇸

Tustin, California, United States

Medical Building

🇺🇸

Long Beach, California, United States

Ney York Hospital Cornell Med Center

🇺🇸

New York, New York, United States

University of Missouri Dept. of Neurology

🇺🇸

Columbia, Missouri, United States

Lovelace Scientific Resources, Inc.

🇺🇸

Albuquerque, New Mexico, United States

The Cleveland Clinic Foundation

🇺🇸

Cleveland, Ohio, United States

Ohio State University Medical Center

🇺🇸

Columbus, Ohio, United States

University Clinic for Diabetes, Endocrinology and Metabolic

🇭🇷

Zagreb, Croatia

Policlinic University

🇮🇹

Napoli, Italy

Hosptal of Parma Department of Medicine

🇮🇹

Parma, Italy

University Hospital

🇩🇰

Hvidovre, Denmark

University Clinic of Internal Medicine

🇭🇷

Zagreb, Croatia

Hospital Geriatrico Diabetological Service

🇮🇹

Padova, Italy

Hospital Jean Verdler

🇫🇷

Bondy Cedex, France

City of Hope National Medical Center

🇺🇸

Duarte, California, United States

Leonard R. Strelitz Diabetes Institutes

🇺🇸

Norfolk, Virginia, United States

University of Michigan Medical Center

🇺🇸

Ann Arbor, Michigan, United States

East Carolina University, School of Medicine

🇺🇸

Greenville, North Carolina, United States

University of Texas South Western Medical Center

🇺🇸

Dallas, Texas, United States

Diabetes & Glandular Disease Center

🇺🇸

San Antonio, Texas, United States

Mayo Clinic Rochester

🇺🇸

Rochester, Minnesota, United States

Beth Israel Medical Center

🇺🇸

Boston, Massachusetts, United States

University of California

🇺🇸

San Francisco, California, United States

University of Pittsburgh Medical Center

🇺🇸

Pittsburgh, Pennsylvania, United States

Baylor College of Medicine

🇺🇸

Houston, Texas, United States

Hospital del Mar Department Neurophysiology

🇪🇸

Barcelona, Spain

Manchester Royal Infirmary Department of Medicine

🇬🇧

Manchester, United Kingdom

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