Recruiting

Testing injections for knee osteoarthritis pain relief

Plain-English translation of NCT06917404 on ClinicalTrials.gov ↗ · Source last updated May 2026 · Translation generated June 2026 · How we translate trials

Phase 3 — Testing in thousands of people, comparing the treatment against what doctors currently use. This is the last big step before approval.

What is this trial?

This research study is testing whether pentosan polysulfate sodium, given as twice-weekly injections under the skin, can safely and effectively reduce knee osteoarthritis pain. Half of the participants will receive the medication, and half will receive a placebo (a harmless saltwater injection that looks identical). The study will track how much pain relief the medication provides compared to placebo over several months.

Many people with knee osteoarthritis don't get enough pain relief from current treatments like physical therapy, over-the-counter pain relievers, or injections into the knee joint. This trial is testing whether this medication might offer a new option for people whose pain isn't adequately controlled.

Do you qualify?

You likely qualify if…

you are 18 years or older
you have been diagnosed with knee osteoarthritis that shows up on X-rays
you have had moderate to severe knee pain (rated 4-9 on a 0-10 scale) for at least 6 months
you have tried and not benefited from at least two different types of osteoarthritis treatments in the past year (such as physical therapy, weight loss, pain relievers, or injections)
you are willing to stop taking NSAIDs (like ibuprofen or naproxen) and other pain medications during the study
you can commit to attending study visits and receiving injections twice weekly for 6 weeks, then follow-up visits for up to one year

You likely don't qualify if…

you have a history of bleeding disorders or blood clotting problems, including immune-related low platelet counts
you have had recent stomach ulcers or significant bleeding in your digestive tract in the past year
you have had brain, spine, eye surgery or bleeding in the brain within the past 12 months
you have other severe pain conditions (such as fibromyalgia) that might interfere with assessing your knee pain
you are pregnant, planning to become pregnant, or unable to use reliable contraception during the study

What participation looks like

If you qualify, you'll attend a 7-week screening period where you'll keep a pain diary and have X-rays taken. Then you'll receive twice-weekly injections under your skin for 6 weeks — either the medication or placebo (you won't know which). You'll continue tracking your pain and attend regular check-in visits. After the 6-week injection period ends, you'll have follow-up visits over the next year so researchers can see how long any pain relief lasts. The entire study lasts up to 64 weeks (about 15 months).

AI-generated summary from trial data · Jun 21, 2026 · Not medical advice

Testing injections for knee osteoarthritis pain relief

What is this trial?

Do you qualify?

What participation looks like

Trial locations(56 sites)