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Study on Pentosan Polysulfate Sodium for Knee Osteoarthritis Pain in Patients

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of a treatment for knee osteoarthritis pain, a common condition that causes pain and stiffness in the knee joint. The treatment being tested is called Pentosan Polysulfate Sodium (PPS), which is given as an injection under the skin. The study will compare the effects of PPS with a placebo to see how well it works in reducing knee pain and improving knee function.

The purpose of the study is to evaluate how effective PPS is in treating knee pain and improving the ability to move the knee in people with knee osteoarthritis. Participants in the study will receive either PPS or a placebo over a period of time. The study is designed to be adaptive, meaning it can be adjusted based on the results as it progresses. It is conducted in two stages, and participants will not know whether they are receiving PPS or the placebo, as the study is double-blind.

Throughout the study, participants will be monitored for changes in their knee pain and function. The study aims to provide valuable information on whether PPS can be a beneficial treatment for those suffering from knee osteoarthritis pain. The trial will last for several weeks, and participants will be asked to stop using other pain medications, except for acetaminophen, during the study period.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, you will be randomly assigned to receive either the study medication, pentosan polysulfate sodium, or a placebo. A placebo is a substance with no active medication, used to compare the effects of the actual drug.

  2. Step 2

    Initial assessment

    An initial assessment will be conducted to evaluate your knee pain and function. This will involve completing a questionnaire known as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), which measures pain and physical function.

  3. Step 3

    Medication administration

    You will receive the study medication or placebo through a subcutaneous injection, which means it will be injected under the skin. The exact dosage and frequency will be determined by the study protocol.

  4. Step 4

    Ongoing assessments

    Throughout the study, you will have regular assessments to monitor changes in your knee pain and function. These assessments will occur at specified intervals, such as Day 56 and Day 84, using the WOMAC questionnaire.

  5. Step 5

    Use of rescue medication

    If needed, you may use paracetamol as a rescue medication for pain relief. The dosage will be 500 mg tablets, taken orally as required, but you should not exceed the maximum daily dose as advised by the study team.

  6. Step 6

    Completion of the study

    At the end of the study period, a final assessment will be conducted to evaluate the overall effect of the treatment on your knee pain and function. This will help determine the effectiveness of the study medication.

Who can join the trial?

8 criteria

  • Participants must be 18 years of age or older.
  • Must have a clinical diagnosis of knee osteoarthritis (OA) in the affected knee, according to the American College of Rheumatology 1986 criteria. (A clinical diagnosis means a doctor has confirmed the condition based on specific guidelines.)
  • Must have a radiographic diagnosis of knee OA, confirmed by a radiologist, classified as K-L Grade 2, 3, or 4 on a standing X-ray of the affected knee. (A radiographic diagnosis means the condition is confirmed through an X-ray image.)
  • Must have knee osteoarthritis pain that has not improved with conservative treatments for at least 6 months before the screening. (Conservative treatments include non-surgical methods like physical therapy or medication.)
  • Must have an average pain score between 4 to 10 in the affected knee at screening, and a minimum pain score of 4 on either walking on a flat surface or climbing stairs at screening. (Pain scores are usually measured on a scale from 0 to 10, where 0 means no pain and 10 means the worst pain possible.)
  • Must have an average function score between 4 to 10 in the affected knee at screening. (Function scores assess how well the knee is working.)
  • Must have a body mass index (BMI) between 18.0 to 35.0 kg/m². (BMI is a measure of body fat based on height and weight.)
  • Must be willing to stop using certain pain medications, such as oral and topical NSAIDs, and all other systemic pain medications (except acetaminophen/paracetamol as per rescue protocol) from 2 weeks before the start of the study until the end of the study. (NSAIDs are non-steroidal anti-inflammatory drugs, commonly used to relieve pain and reduce inflammation.)

Who cannot join the trial?

10 criteria

  • Patients with any other type of arthritis besides knee osteoarthritis cannot participate.
  • Patients who have had knee surgery in the past 6 months are not eligible.
  • Patients currently receiving treatment for knee pain with injections or surgery cannot join the study.
  • Patients with severe knee pain that requires immediate surgery are excluded.
  • Patients with a history of allergic reactions to the study medication cannot participate.
  • Patients with any serious medical condition that could interfere with the study results are not eligible.
  • Pregnant or breastfeeding women cannot take part in the study.
  • Patients who are participating in another clinical trial are not allowed to join this study.
  • Patients with a history of drug or alcohol abuse in the past year are excluded.
  • Patients who cannot follow the study procedures or attend the required visits are not eligible.
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Investigated drugs

Pentosan Polysulfate Sodium is a medication being studied for its potential to relieve pain and improve function in people with knee osteoarthritis. Osteoarthritis is a condition that causes pain and stiffness in the joints, and this medication is thought to help by reducing inflammation and possibly protecting the cartilage in the knee. The study aims to see how effective this medication is in reducing knee pain and improving the ability to move and use the knee in everyday activities.

What is already known about the treatment

Pentosan Polysulfate Sodium – This medication is administered orally in the form of capsules. It is currently being studied in clinical trials to assess its effectiveness in treating knee osteoarthritis pain. The main therapeutic indication for Pentosan Polysulfate Sodium is to alleviate pain and improve function in individuals suffering from knee osteoarthritis. At the molecular level, it is believed to work by reducing inflammation and protecting cartilage in the joints. It is classified pharmacologically as a disease-modifying osteoarthritis drug (DMOAD).

Investigated diseases

Knee Osteoarthritis – Knee osteoarthritis is a degenerative joint disease characterized by the breakdown of cartilage in the knee joint. As the cartilage wears away, bones begin to rub against each other, causing pain, swelling, and reduced motion in the joint. Over time, the joint may become stiff and lose its normal shape, leading to further discomfort and difficulty in movement. The progression of the disease can lead to the formation of bone spurs and a decrease in the space between the bones in the joint. This condition often results in chronic pain and can significantly impact daily activities. The severity of symptoms can vary, with some individuals experiencing mild discomfort and others facing significant mobility challenges.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IVTrial ID2022-500228-31-00Protocol codePARA_OA_002Estimated enrolment898 patientsSponsorParadigm Biopharmaceuticals (USA) Inc.

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