NCT06100822

Brief Summary

The purpose of the current exploratory clinical trial is to determine the effect of oral ingestion of metformin (OIM) in non-diabetic patients with chronic Achilles tendon pain. The trial has two aims; 1) to assess the effects of OIM treatment on tendon pain, and 2) to determine the effects of OIM capsules on tendon healing and repair. Twenty participants will be treated with metformin capsules for 16 weeks combined with a home exercise program. A comparison group of 20 participants will be treated with placebo tablets along with home exercise program.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
40

participants targeted

Target at P50-P75 for phase_1

Timeline
3mo left

Started May 2024

Typical duration for phase_1

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress89%
May 2024Aug 2026

First Submitted

Initial submission to the registry

October 9, 2023

Completed
16 days until next milestone

First Posted

Study publicly available on registry

October 25, 2023

Completed
7 months until next milestone

Study Start

First participant enrolled

May 24, 2024

Completed
1.9 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 1, 2026

Completed
3 months until next milestone

Study Completion

Last participant's last visit for all outcomes

August 1, 2026

Expected
Last Updated

November 10, 2025

Status Verified

November 1, 2025

Enrollment Period

1.9 years

First QC Date

October 9, 2023

Last Update Submit

November 6, 2025

Conditions

Keywords

Achilles TendonMetforminAchilles TendinopathyChronic Pain

Outcome Measures

Primary Outcomes (1)

  • Change in Victorian Institute of Sport Assessment - Achilles (VISA-A) Score

    The VISA-A is a self-administered questionnaire that asks about Achilles tendon pain, function, and activity. Scores range from 0 to 100 with a low score indicating more severe pain.

    baseline, 4 weeks, 16 weeks

Secondary Outcomes (11)

  • Change in VAS score

    baseline, 4 weeks, 16 weeks

  • Change in tendon thickness

    baseline, 4 weeks, 16 weeks

  • Change in tendon cross-sectional area

    baseline, 4 weeks, 16 weeks

  • Change in tendon neovascularization

    baseline, 4 weeks, 16 weeks

  • Change in tendon hypoechogenicity

    baseline, 4 weeks, 16 weeks

  • +6 more secondary outcomes

Study Arms (2)

Placebo Group, Placebo Capsules

PLACEBO COMPARATOR

Placebo Group (n=20) Week 1: One placebo capsule (500 mg) daily Week 2: Two placebo capsules (1,000 mg) daily Week 3: Three placebo capsules (1,500 mg) daily Week 4-16: Four placebo capsules (2,000 mg) daily

Drug: Placebo

Treatment Group, Metformin Capsules

EXPERIMENTAL

Treatment Group (n=20) Week 1: One metformin ER capsule (500 mg) daily Week 2: Two metformin (ER) capsules (1,000 mg) daily Week 3: Three metformin (ER) capsules (1,500 mg) daily Week 4-16: Four metformin (ER) capsules (2,000 mg) daily

Drug: Metformin

Interventions

500 mg capsules of Metformin Extended Release

Also known as: Glucophage, Glucophage XR, Metformin Extended Release, Metformin ER
Treatment Group, Metformin Capsules

500 mg capsules of placebo pills

Placebo Group, Placebo Capsules

Eligibility Criteria

Age18 Years - 50 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64)

You may qualify if:

  • Willing and able to provide informed consent for participation
  • Clinical diagnosis of Achilles tendinopathy
  • Pain disability index score of between 20 - 70 points (0-100 scale VISA-A)
  • Sonopalpation tenderness with tendon thickening and/or loss of fibrillary architecture.
  • Ability to read, speak, and understand English

You may not qualify if:

  • Any intervention (corticosteroids or other orthobiologic intervention as injection) to targeted tissue within the last 6 months.
  • Previous Achilles tendon surgery.
  • Known platelet abnormality or hematological disorder.
  • Presence of other conditions that might affect the functional scale of the indexed limb.
  • Unwillingness to be randomized.
  • Body Mass Index (BMI) greater than 30.
  • Occult tear in the indexed tendon.
  • Systemic inflammatory disease.
  • Use of fluoroquinolone in the past 6 months.
  • Subjects must not be pregnant or breastfeeding, or planning to become pregnant or breastfeed during the course of the trial
  • Chronic kidney disease (eGFR \<60)
  • Diagnosis of diabetes mellitus or elevated HbA1c at screening (\> 6.5)
  • Unable to take an oral medication in a non crushable pill form
  • Taking metformin presently or within the last 6 months
  • History of allergy to metformin
  • +5 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Pittsburgh

Pittsburgh, Pennsylvania, 15213, United States

RECRUITING

MeSH Terms

Conditions

TendinopathyChronic Pain

Interventions

Metformin

Condition Hierarchy (Ancestors)

Muscular DiseasesMusculoskeletal DiseasesTendon InjuriesWounds and InjuriesPainNeurologic ManifestationsSigns and SymptomsPathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

BiguanidesGuanidinesAmidinesOrganic Chemicals

Study Officials

  • James H Wang, PhD

    University of Pittsburgh

    PRINCIPAL INVESTIGATOR

Central Study Contacts

James H Wang, PhD

CONTACT

Study Design

Study Type
interventional
Phase
phase 1
Allocation
RANDOMIZED
Masking
QUADRUPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR INVESTIGATOR
PI Title
Professor

Study Record Dates

First Submitted

October 9, 2023

First Posted

October 25, 2023

Study Start

May 24, 2024

Primary Completion

May 1, 2026

Study Completion (Estimated)

August 1, 2026

Last Updated

November 10, 2025

Record last verified: 2025-11

Data Sharing

IPD Sharing
Will share

Data obtained through this study may be provided to qualified researchers. Data or samples shared will be coded, with no PHI included. Approval of the request and execution of all applicable agreements (i.e. a material transfer agreement) are prerequisites to the sharing of data with the requesting party.

Shared Documents
STUDY PROTOCOL
Time Frame
Data requests can be submitted starting 9 months after article publication and the data will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis.
Access Criteria
Access to trial IPD can be requested by qualified researchers engaging in independent scientific research, and will be provided following review and approval of a research proposal and Statistical Analysis Plan (SAP) and execution of a Data Sharing Agreement. For more information or to submit a request, please contact wanghc@pitt.edu

Locations