NCT06574191

Brief Summary

The goal of this clinical trial is to understand the patient and clinic visit characteristics that affect health outcomes for individuals with knee osteoarthritis (OA) pain using topical diclofenac gel. The main questions it aims to answer are:

  • What baseline patient characteristics predict response to topical diclofenac?
  • Does patient physiology during the study visit predict response to topical diclofenac?
  • Do study visit characteristics predict response to topical diclofenac? Participants will:
  • attend 2 study visits to complete study questionnaires and have blood drawn
  • apply topical diclofenac to their knee for 8 weeks
  • complete biweekly questions about knee pain and diclofenac use between study visits

Trial Health

77
On Track

Trial Health Score

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

Enrollment
220

participants targeted

Target at P75+ for not_applicable knee-osteoarthritis

Timeline
20mo left

Started Jan 2025

Longer than P75 for not_applicable knee-osteoarthritis

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

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress44%
Jan 2025Jan 2028

First Submitted

Initial submission to the registry

May 15, 2024

Completed
3 months until next milestone

First Posted

Study publicly available on registry

August 27, 2024

Completed
5 months until next milestone

Study Start

First participant enrolled

January 29, 2025

Completed
3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

January 27, 2028

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

January 27, 2028

Last Updated

March 30, 2026

Status Verified

March 1, 2026

Enrollment Period

3 years

First QC Date

May 15, 2024

Last Update Submit

March 24, 2026

Conditions

Outcome Measures

Primary Outcomes (2)

  • Knee Pain

    Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score from the index knee at 8 weeks. Score range 0-20. Higher scores signify worse pain.

    8 weeks

  • Knee Function

    Western Ontario and McMaster Universities Arthritis Index (WOMAC) physical function score from the index knee at 8 weeks. Score range 0-68. Higher scores signify worse function.

    8 weeks

Secondary Outcomes (6)

  • Global Impressions

    30 minutes

  • Non-verbal Behaviors

    30 minutes

  • Skin conductance index measure

    30 minutes

  • Change in patient skin conductance response

    30 minutes

  • Heart rate variability index measure

    30 minutes

  • +1 more secondary outcomes

Study Arms (1)

Diclofenac

EXPERIMENTAL

All study participants receiving topical diclofenac gel 1%. Participants will be instructed to apply 4 grams of the gel to the index knee at least once per day, and up to 4 times per day, for 8 weeks.

Drug: Topical Diclofenac gel 1%

Interventions

Topical NSAID

Diclofenac

Eligibility Criteria

Age50 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • English-speaking
  • years of age or older
  • Radiographically confirmed knee OA of K/L grade 2 or higher within the past 2 years
  • Knee pain at least 15 days/month.
  • Average worst daily pain 3/10 or higher over a two-week period.

You may not qualify if:

  • Medical contraindication to taking NSAIDs such as: history of coronary artery bypass graft, myocardial infarction, coronary artery stent placement, or stroke within the past 6 months; systolic heart failure with ejection fraction \<45%; chronic kidney disease stage ≥4; severe gastrointestinal bleed or stomach ulcer within the past 6 months; current pregnancy; cirrhosis; currently taking blood thinners (aspirin 81 mg daily is okay); allergy to NSAIDs or aspirin; or any other medical contraindication to using topical NSAIDs.
  • Inflammatory arthritis
  • Partial or total knee replacement of the index knee
  • Recent therapeutic injection of the index knee (less than 12 weeks)
  • Planned knee/lower limb surgery during the two-month study period
  • Active cancer treatment not in remission or life expectancy less than 6 months
  • Inability to provide informed consent (e.g. dementia)
  • Current use of topical or oral NSAIDs more than 3 days per week.
  • Inability to receive text messages or emails to complete questionnaires between study visits.
  • Unable to follow the study protocol.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of California Davis Health

Sacramento, California, 95817, United States

RECRUITING

MeSH Terms

Conditions

Osteoarthritis, Knee

Condition Hierarchy (Ancestors)

OsteoarthritisArthritisJoint DiseasesMusculoskeletal DiseasesRheumatic Diseases

Study Officials

  • Michelle Dossett, MD, PhD

    University of California, Davis

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Michelle Dossett, MD, PhD

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NA
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
SINGLE GROUP
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

May 15, 2024

First Posted

August 27, 2024

Study Start

January 29, 2025

Primary Completion (Estimated)

January 27, 2028

Study Completion (Estimated)

January 27, 2028

Last Updated

March 30, 2026

Record last verified: 2026-03

Data Sharing

IPD Sharing
Will share

De-identified questionnaire and COMT genotype data will be available upon reasonable written request after publication and upon completing a data transfer agreement. Raw video and physiologic data will not be shared due to participant confidentiality/privacy.

Shared Documents
STUDY PROTOCOL, SAP, ICF
Time Frame
Data will be available following publication of those data.
Access Criteria
Completion of a data transfer agreement.

Locations