Assessment of GRT6005 in Painful Osteoarthritis of the Knee

A Randomized 4 Week Phase IIa Trial Evaluating the Efficacy, Safety, and Tolerability of GRT6005, a New Centrally Acting Analgesic, in Subjects With Moderate to Severe Pain Due to Osteoarthritis (OA) of the Knee

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01357837

Enrollment

207

Registered

2011-05-23

Start date

2011-05-31

Completion date

2011-12-31

Last updated

2021-07-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Osteoarthritis of the Knee

Keywords

Osteoarthritis, knee, Analgesia, Pain, Painful

Brief summary

The purpose of the trial is to determine whether GRT6005 is effective in patients with pain due to osteoarthritis of the knee.

Detailed description

The purpose of this study is to evaluate the safety, tolerability and efficacy of 3 doses of GRT6005 taken once daily for 4 weeks in outpatients with moderate-to-severe painful osteoarthritis of the knee.

Interventions

DRUGMatching Placebo

2 capsules of matching placebo once a day, in the morning, for a total of 28 days

DRUGGRT6005

2 capsules containing a total of 75 µg GRT6005 once a day, in the morning, for a total of 28 days

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

40 Years to 75 Years

Healthy volunteers

Inclusion criteria

* painful Osteoarthritis of the knee based on American College of Rheumatology Criteria * signed informed consent * on stable analgesic medications for painful osteoarthritis with regular analgesic intake for at least 3 months * pain intensity score of 4 or greater on the 11-point numeric rating scale (where 0 indicates no pain and 10 indicates pain as bad as you can imagine).

Exclusion criteria

* Substance Abuse * Significant cardiac disease * Presence of risk factors for Torsades de Pointes and chronic severe cardiac disease * History of seizure disorder * Chronic gastrointestinal disease * Conditions that contribute and confound to the assessment of pain * Surgery or painful procedure during or within 3 months of enrollment * Cancer * Subjects with impaired renal function * Subjects with impaired hepatic function * Female subjects who are breastfeeding * History of chronic hepatitis B or C or human immunodeficiency virus infection, or presence of acute hepatitis A, B, or C within the past 3 months. * Clinically relevant history of hypersensitivity or allergy to paracetamol, opioids or the excipients.

Design outcomes

Primary

Measure	Time frame
Change from baseline in the pain intensity scores during the last week of the 4-week treatment period	4 weeks

Secondary

Measure	Time frame
Change from baseline in quality of health as measured by Short Form-12 Health Survey	4 weeks
Response measured in percentage change of pain intensity since baseline	4 weeks
Leeds Sleep Evaluation Questionnaire to quantify subjective impressions of sleep and waking	4 weeks
Patient's Global Impression of Change (PGIC)	4 weeks
Clinician's Global Impression of Change (CGIC)	4 weeks
Weekly current pain intensity changes from baseline	4 weeks
Change from baseline in the Western Ontario McMaster Questionnaire (WOMAC) Global Score Assessing Pain, Disability and Joint Stiffness of the Knee Over the 4 week treatment period	4 weeks
Quality of Life EuroQoL-5 Dimension score, change from baseline	4 weeks
Clinical Opioid Withdrawal Scale	4 weeks
Plasma concentration	4 weeks
Discontinuation from study due to treatment related adverse events	4 weeks
Time to withdrawal from study	4 weeks
Rescue medication use	4 weeks

Countries

Austria, Poland, Spain

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026