The AMPK Modulator Metformin as a Novel Adjunct to Conventional Therapy in Rheumatoid Arthritis Patients

Study Overview
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Brief Summary
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Metformin, a traditional antidiabetic medication, exerts glucose lowering effects by activating AMP-activated protein kinase (AMPK), a critical enzyme involved in the lipid and glucose metabolism. In addition to the antidiabetic effect, metformin has been shown to inhibit Lipopolysaccharide-Induced Inflammation (LPS)-induced inflammation by suppress NF-κB production, which is also regulated by AMPK. These regulatory effects of AMPK on the inflammation, immune and fibroblast-like synovial cells have prompted the investigation on the effects of metformin on rheumatoid arthritis.

Detailed Description
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Rheumatoid arthritis (RA) is a chronic, multisystem inflammatory disorder of unknown etiology. It is characterized by polyarthritis and systemic inflammation. The inflammation in the hyperplastic synovium can destruct the structure of affected joints. Although the exact molecular mechanism underlying the pathogenesis of RA remains unknown, it is suggested that T helper cell (Th) 17 plays a central role. Interleukin (IL)-17, mostly secreted by Th17, has synergistic effects with tumor necrosis factor- (TNF-α), IL-1β and IL-6 in cases of RA. Metformin, a traditional antidiabetic medication, exerts glucose lowering effects by activating AMP-activated protein kinase (AMPK), a critical enzyme involved in the lipid and glucose metabolism. In addition to the antidiabetic effect, metformin has been shown to inhibit Lipopolysaccharide-Induced Inflammation (LPS)-induced inflammation by suppress NF-κB production, which is also regulated by AMPK . In addition, metformin activated AMPK may inhibit mammalian target of rapamycin (mTOR), which then regulate the differentiation of T cells in vitro and in vivo. In particular, AMPK has been reported to be associated with the inhibition of TH17 cells through suppressing the phosphorylation of mTOR and its downstream signal transducers, suggesting the therapeutic potential of AMPK agonists. Besides the imbalance between Th17 cells and Treg cells is responsible for the chronic inflammation in RA, synovium hyperplasia also plays a central role in the joint destruction. It has been reported that rapamycin, an inhibitor of mTOR, is able to significantly reduce fibroblastlike synovial cell invasion in RA via suppressing mTOR signaling pathway. These regulatory effects of AMPK on the inflammation, immune and fibroblast-like synovial cells have prompted the investigation on the effects of metformin on rheumatoid arthritis.

Official Title
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The AMPK Modulator Metformin as a Novel Adjunct to Conventional Therapy in Rheumatoid Arthritis Patients: A Proof-of-Concept, Randomized, Double-Blind, Placebo-Controlled Trial.

Conditions
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Rheumatoid Arthritis

Intervention / Treatment
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* Drug: Metformin
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with active rheumatoid arthritis based on DAS28 score. Patients received the standard therapy (i.e. one or more conventional DMARDs) for at least three months. Exclusion Criteria: Known hypersensitivity to metformin. Patients who have a prior diagnosis with diabetes mellitus. Patients receive metformin for any other indications. Patients with congestive heart failure. Patients with a history of myocardial infarction. Patients with severe anemia. Patients with active infections or other inflammatory diseases. Patients receiving biological therapy. Pregnancy or lactation. Patients with impaired liver functions. Patients with impaired kidney functions (serum creatinine concentrations ≥1.5 and ≥1.4 mg/dL in males and females respectively). Patients with malignancies.

Ages Eligible for Study
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Minimum Age: 18 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Control group<br>patients will receive the standard therapy (methotrexate) plus placebo tablets | Drug: Placebo<br>* Placebo tablet plus plus Methotrexate 7.5 mg weekly<br>|
| Experimental: Metformin group<br>patients will receive the standard therapy plus 1 g metformin daily. | Drug: Metformin<br>* 1000 mg of Metformin table taken orally daily plus Methotrexate 7.5 mg weekly<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ACR 20% improvement criteria (ACR20) response rate | based on tender and swollen joint counts, patient's assessment of pain, patient and physician global assessment of arthritis, Health Assessment Questionnaire Disability Index (HAQ DI), and CRP level | week 12 | 
| ACR50 & ACR70 response rate | based on tender and swollen joint counts, patient's assessment of pain, patient and physician global assessment of arthritis, Health Assessment Questionnaire Disability Index (HAQ DI), and CRP level | week 12 | 
| Disease activity scale in 28 joints (DAS-28) | Scale assessing severity of rheumatoid arthritis based on number of tender, swollen joints, erythrocyte sedimentation rate (ESR) levels, and patient self-assessment of his condition (global health assessment). Whereas 28 describes the number of different joints including in the measurement: proximal interphalangeal joints (10 joints), metacarpophalangeal joints (10), wrists (2), elbows (2), shoulders (2), knees (2). | week 12 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the Short Form 36 (SF-36) Health Survey | both the physical component score [PCS] and the mental component score [MCS]) | week 12 | 
| HAQ-DI (Health Assessment Score- Disability index) | HAQ-DI (Health Assessment Score- Disability index), in which patients are asked to rate their capacity to perform 20 activities of daily living (ADL). Scoring within each section is from 0 (without any difficulty) to 3 (unable to do). For each section the score given to that section is the worst score within the section | week 12 | 
| AMPK expression | AMPK expression in synovium or serum | at baseline and at week 12 | 
| IGF-IR expression | IGF-IR expression in Blood | at baseline and at week 12 | 
| TNF-α | Serum level Tumor necrosis factor- alpha (TNF-α) | at baseline and at week 12 | 
| TGF-Beta1 | Serum level tissue growth factor beta 1 | at baseline and at week 12 | 
| Inteleukins | Serum levels of Interleukins (IL) IL-17, IL-1β , IL-6 & IL-10 | at baseline and at week 12 | 
| CRP | Serum level of C-reactive protein (CRP) | at baseline and at week 12 | 
| Drug Adverse effects | Adverse effect incidence: adverse effect will be reported by patients or their caregivers and recorded by investigator. | 3 months |