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Completed

NCT Number: NCT05248386

Efficacy and Safety of RTX-GRT7039 in Adult Subjects With Knee Osteoarthritis

A double-blind, randomized, placebo-controlled, parallel-group, multi-site, clinical trial to confirm the efficacy and safety of repeated injections of RTX-GRT7039 versus placebo in patients who have pain associated with osteoarthritis of the knee despite standard of care.

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Key information

Conditions

Osteoarthritis Arthritis Joint Diseases Musculoskeletal Diseases Rheumatic Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

Cook Street Medical Clinic, Victoria, British Columbia, Canada

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About this study

This trial comprises a total observation period of up to 52 weeks.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • The participant has given written informed consent to participate.
  • The participant is 18 years of age or older at the Screening Visit.
  • The participant has a diagnosis of osteoarthritis of the knee based on American College of Rheumatology criteria and functional capacity class of I to III.
  • There is a documented history indicating that participant has insufficient pain relief with previous Standard of Care.

Exclusion criteria

  • The participant has past joint replacement surgery of the index knee.
  • The participant has a history of significant trauma or surgery (e.g., open or arthroscopic) to the index knee within 12 months of Screening.
  • The participant has periarticular pain from any cause other than osteoarthritis, including referred pain, bursitis, or tendonitis.
  • The participant has clinical hip osteoarthritis on the side of the index knee.
  • The participant has pre-existing osteonecrosis, subchondral insufficiency fracture, atrophic osteoarthritis, severe bone on bone osteoarthritis, knee pain attributable to disease other than osteoarthritis, or the participant has rapidly progressing osteoarthritis (RPOA) Type I or Type II.
  • The participant has significant malalignment of anatomical axis (medial angle formed by the femur and tibia) of the target knee (varus >10, valgus >10) by X-ray as assessed by independent Central Readers at Screening Visit.
  • The participant has other conditions that could affect trial endpoint assessments of the index knee.
  • The participant has current clinically significant disease(s) or condition(s) that may affect efficacy or safety assessments, or any other reason which, in the investigator's opinion, may preclude the participant's participation for the full duration of the trial.
  • The participant has a history of hypersensitivity to resiniferatoxin (RTX) or any similar component (capsaicin, chili peppers).
  • The participant is currently participating or was participating in another investigational drug trial within 3 months prior to the Screening Visit.
  • The participant is an employee of the investigator or trial site, with direct involvement in the proposed trial or other trials under the direction of that investigator or trial site or is a family member of the employees or the investigator.

Treatment and study plan

RTX-GRT7039

Drug

RTX-GRT7039 intra-articular injection.

Placebo

Drug

Placebo matching RTX-GRT7039 intra-articular injection.

Primary outcomes

  1. Least Squares Mean (Standard Error) [LS-mean (SE)] Change From Baseline in WOMAC Pain Subscale Score at Week 12

    Time frame: Baseline up to Week 12

    Difference in mean change from baseline in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale score at Week 12 in the index knee using an 11-point (0-10) numeric rating scale (NRS) between RTX-GRT7039 and placebo. The WOMAC pain subscale consists of 5 questions using an 11-point numeric rating scale (NRS, from 0 = no pain to 10 = pain as bad as you can imagine). The scores are averaged over the number of questions.

Secondary outcomes

  1. LS-mean (SE) Change From Baseline in WOMAC Pain Subscale Score at Week 26

    Time frame: From Baseline up to Week 26

    Difference in mean change from baseline in WOMAC pain subscale score at Week 26 in the index knee using an 11-point (0-10) numeric rating scale (NRS) between RTX-GRT7039 and placebo. The WOMAC pain subscale consists of 5 questions using an 11-point numeric rating scale (NRS, from 0 = no pain to 10 = pain as bad as you can imagine). The scores are averaged over the number of questions.

  2. LS-mean (SE) Change From Baseline in WOMAC Pain Subscale Score at Week 52

    Time frame: From Baseline up to Week 52

    Difference in mean change from baseline in WOMAC pain subscale score at Week 52 in the index knee using an 11-point (0-10) numeric rating scale (NRS) between RTX-GRT7039 and placebo. The WOMAC pain subscale consists of 5 questions using an 11-point numeric rating scale (NRS, from 0 = no pain to 10 = pain as bad as you can imagine). The scores are averaged over the number of questions.

  3. LS-mean (SE) Change From Baseline in WOMAC Physical Function Subscale Score at Week 12

    Time frame: From Baseline up to Week 12

    Difference in mean change from baseline in WOMAC physical function subscale score at Week 12 in the index knee using an 11-point (0-10) numeric rating scale (NRS) between RTX-GRT7039 and placebo. The WOMAC pain subscale consists of 5 questions using an 11-point numeric rating scale (NRS, from 0 = no pain to 10 = pain as bad as you can imagine). The scores are averaged over the number of questions.

  4. LS-mean (SE) Change From Baseline in WOMAC Physical Function Subscale Score at Week 26

    Time frame: From Baseline up to Week 26

    Difference in mean change from baseline in WOMAC physical function subscale score at Week 26 in the index knee using an 11-point (0-10) numeric rating scale (NRS) between RTX-GRT7039 and placebo. The WOMAC pain subscale consists of 5 questions using an 11-point numeric rating scale (NRS, from 0 = no pain to 10 = pain as bad as you can imagine). The scores are averaged over the number of questions.

  5. LS-mean (SE) Change From Baseline in WOMAC Physical Function Subscale Score at Week 52

    Time frame: From Baseline up to Week 52

    Difference in mean change from baseline in WOMAC physical function subscale score at Week 26 in the index knee using an 11-point (0-10) numeric rating scale (NRS) between RTX-GRT7039 and placebo. The WOMAC pain subscale consists of 5 questions using an 11-point numeric rating scale (NRS, from 0 = no pain to 10 = pain as bad as you can imagine). The scores are averaged over the number of questions.

Sponsors and collaborators

Lead sponsor

Grünenthal GmbH

Industry

Registry information

Official study title

A Randomized, Double-blind, Placebo-controlled, Phase III Trial to Evaluate the Efficacy and Safety of Intra-articular Injections of RTX-GRT7039 in Adult Subjects With Pain Associated With Osteoarthritis of the Knee

Important dates

Study start
2022
Primary completion
2024
Study completion
2024
First posted
Feb 21, 2022
Registry last updated
Mar 18, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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