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Osteoarthritis, KneeROSANCT04045431

Treatment of Knee Osteoarthritis With PAAG-OA

A study testing PAAG-OA and Synvisc-One in people with Osteoarthritis, Knee, run by Contura at 3 sites in Denmark.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This is a multi-center, randomized, double-blind clinical investigation to compare the effectiveness of intra-articular polyacrylamide hydrogel (PAAG-OA) and a hyaluronic acid, Synvisc-One to induce symptomatic benefit in subjects with knee osteoarthritis. Read more about this study

Who is it for?
Ages 40 years and older
Conditions the study is for
Osteoarthritis, Knee
What is being tested?
PAAG-OA and Synvisc-One
Could I receive a placebo?
No, everyone receives an active treatment
How many people
238 participants
Where
3 sitesDenmark
Study dates
15 May 2019to 10 Mar 2025
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 40 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Signed and dated informed consent form
  • Stated willingness to comply with all study procedures and availability for the duration of the study
  • Male or female, aged ≥ 40 years
  • Clinical diagnosis of knee OA American College of Rheumatology criteria confirmed by radiology
  • Definite radiographic OA in the most symptomatic knee (target knee) at mild to moderate-stage (Kellgren-Lawrence grades 2 or 3)
  • Stable dose of analgesics for the past four weeks
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  • NRS (11 points (0-10) pain intensity numerical rating scale) ≥ 4 in target knee, during the past week when walking
  • Body Mass Index (BMI) between 20-35
  • For females of reproductive potential: use of adequate contraception must be used throughout the trial

Who cannot join

  • Female participants who are pregnant, lactating or planning pregnancy during the course of the clinical investigation
  • Contraindications to PAAG-OA or Synvisc-One®, according to IB or Instruction for Use (IFU)
  • Previous intra-articular injection of polyacrylamide gel in the target knee
  • Previous intra-articular injection with hyaluronic acid or derivatives in target knee in the previous 6 months
  • Significant valgus/varus deformity of the knee, ligamentous laxity or meniscal instability
  • Other diseases in target knee than osteoarthritis
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  • Intra-articular injection of any substance other than hyaluronic acid (e.g. corticosteroids) in the target knee within the last 3 months
  • Acute serious infection of any region that required hospital care or intravenous antibiotic treatment within the last 30 days, or oral antibiotic treatment within the last 14 days
  • Skin disease or infections in the area of the injection site
  • Infected or severely inflamed knees
  • History of sepsis in any joint or any clinical concern for a subacute infectious process in the target knee
  • History of surgery in the target knee within the past 6 months
  • Symptomatic osteoarthritis of the hips, spine or ankle, that interferes with the evaluation of the target knee
  • Planned surgery on any lower extremity
  • Clinically significant venous or lymphatic stasis present in the legs
  • Clinically apparent tense effusion or inflammation in the target knee
  • Suffering from any unstable or severe cardio-vascular disease
  • Any contraindication to intra-articular e.g. anticoagulant therapy or clinical concern for potential coagulopathy (e.g. liver disease)
  • Any foreign material in the target joint
  • Any significant medical condition (e.g. significant psychiatric or neurological disorders or active alcohol/drug abuse), any medical condition that is unstable/poorly controlled or other factors that may interfere with study participation
  • Treatment with systemic steroids
  • History of drug/alcohol abuse, mental dysfunction of other factors limiting their ability to cooperate fully
  • Change in physiotherapy within the previous month
  • Fibromyalgia
  • Inflammatory or other disease/condition which may affect joints (e.g. rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis among others)
  • Haemophilia
  • Any other condition that in the opinion of the investigator put a potential participant at risk or otherwise precludes participation in the trial
  • Known allergic reactions to components of Synvisc-One (avian protein)
  • Known allergic reactions to antibiotics (azithromycin and moxifloxacin) or local anaesthesia
  • Participation in any experimental device study within 6 months prior to enrolment, or participation in an experimental drug study within 1 month prior to enrolment

Trial locations and contacts

3 sites in 1 country.

Denmark3 sites

  • The Parker Institute

    Frederiksberg

  • A2 Reumatologi og idrætsmedicin

    Hillerød

  • Reumatolog i Odense

    Odense

Other trials in Denmark

About this study

Official title: A Multi-centre Randomized, Controlled, Double-blind Clinical Investigation of Intra-articular Polyacrylamide Hydrogel in Subjects With Knee Osteoarthritis Followed by an Open Label Extension Study

This is a multi-center, randomized, double-blind clinical investigation to compare the effectiveness of intra-articular polyacrylamide hydrogel (PAAG-OA) and a hyaluronic acid, Synvisc-One to induce symptomatic benefit in subjects with knee osteoarthritis.

Read the detailed description

The trial is designed as a multi-center, randomised, controlled, double-blind, and parallel-group trial spanning over 12 months with outcome assessments at baseline, 1, 3, 6 and 12 months incl. follow-up period between 2-5 years. Primary endpoint at 6 months. The trial is designed to compare effectiveness and safety of injection of PAAG-OA and Synvisc-One® in participants with knee OA.

Being tested
PAAG-OA, Synvisc-One
Medical subject headings
Osteoarthritis, Knee

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PAAG-OADevice

    Intra-articular injection of 6ml PAAG-OA in the target knee (incl. five (5) years follow-up) period.

  • Synvisc-OneDevice

    Intra-articular injection of 6ml Synvisc-One in the target knee

Study groups in NCT04045431
Study groupRoleWhat they receive
PAAG-OAExperimentalIntra-articular injection with PAAG-OA (polyacrylamide hydrogel)
Receives: Device: PAAG-OA
Synvisc-OneActive comparatorIntra-articular injection with Synvisc-One (hyaluronic acid)
Receives: Device: Synvisc-One

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Comparing one injection of PAAG-OA with one injection of Synvisc-One on pain over 6 months in subjects with knee osteoarthritis

    Change in WOMAC (WOMAC Osteoarthritis Index) pain subscale. Pain is reported in each of five response categories (0=none, 4=extreme)

    Measured: 6 months

Secondary outcomes (4)

  1. WOMAC

    WOMAC (WOMAC Osteoarthritis Index) self reported pain, stiffness and physical function, categories (0=none, 4=extreme)

    Measured: 1, 3, 6 and 12 months

  2. PGA (Patient Global Assessment)

    PGA reported on a 10 cm Visual Analogue Scale

    Measured: 1, 3, 6 and 12 months

  3. EQ-5D-5L, QoL

    EQ-5D-5L, Quality of Life, comprised of descriptive system where each dimension has 5 levels (ranging from no problems to extreme problems) and a 20 cm Visual Analogue Scale (0 = worst health and 100 = best health)

    Measured: 1, 3, 6 and 12 months

  4. OMERACT-OARSI responder criteria

    Per the OMERACT-OARSI criteria, a subject is classified as a positive responder if at least one (1) of the following two (2) conditions is observed at the post-baseline assessment:

    • In either pain (WOMAC pain subscale) or function (WOMAC function subscale), a high improvement in the subscale, where high improvement in a subscale is achieved if there is both a > 50% improvement from Baseline and an absolute change from Baseline of > 20 normalised units (0-100 scale) OR
    • Improvement in at least two (2) of the following three (3):
    1. Improvement in pain (WOMAC pain subscale) defined as > 20% improvement from Baseline and an absolute change from Baseline of > 10 (0-100 scale)
    2. Improvement in function (WOMAC function subscale) defined as > 20% improvement from Baseline and an absolute change from Baseline of > 10 (0-100 scale)
    3. Improvement in PGA defined as > 20% improvement from Baseline and an absolute change from Baseline of > 10 mm (0-100 sc

    Measured: 1, 3, 6 and 12 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 Aug 2019
  2. Study start15 May 2019
  3. Primary completion1 Oct 2020
  4. Study completion10 Mar 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Double blind
Who is masked
Participant, Investigator
Enrolment
238 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04045431
Sponsor's protocol ID
CON-OA-001
Acronym
ROSA
Status last verified
Sep 2026
First submitted
8 Jul 2019
Last updated
16 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • Bliddal H, Beier J, Hartkopp A, Conaghan PG, Henriksen M. Sustained symptom relief and safety over five years following a single intra-articular injection of 2.5[%] polyacrylamide hydrogel in patients with knee osteoarthritis. Clin Exp Rheumatol. 2026 Jul;44(7):1410-1417. doi: 10.55563/clinexprheumatol/bsper8. Epub 2026 Mar 4.

    PubMed 41779591

  • Bliddal H, Beier J, Hartkopp A, Conaghan PG, Henriksen M. Three-year follow-up from a randomised controlled trial of a single intra-articular polyacrylamide hydrogel injection in subjects with knee osteoarthritis. Clin Exp Rheumatol. 2026 May;44(5):996-1003. doi: 10.55563/clinexprheumatol/5lofry. Epub 2025 Dec 11.

    PubMed 41487107

Questions about this trial

What is this clinical trial studying?

A study testing PAAG-OA and Synvisc-One in people with Osteoarthritis, Knee, run by Contura at 3 sites in Denmark.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 30 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 16 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 sites in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Comparing one injection of PAAG-OA with one injection of Synvisc-One on pain over 6 months in subjects with knee osteoarthritis (time frame: 6 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04045431, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Sep 2026.

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