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Phase 3 Study of Once‑Monthly PF‑08653944 for Pain Relief in Adults with Knee Osteoarthritis and Overweight or Obesity

Verified siteInvestigational
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What is this trial about?

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

The study focuses on adults who have Knee osteoarthritis, a condition that causes joint pain and stiffness, together with overweight or obesity, which means having excess body weight. The investigational medicine being tested is called berobenatide, which is given as a subcutaneous injection (an injection placed just under the skin) once each month.

The purpose of the study is to determine whether the monthly dose of berobenatide provides greater relief of knee pain than placebo. Participants will receive either the study drug or a matching placebo for about a year, with regular clinic visits to record pain levels, body weight, and ability to move. Pain and function are measured using the Western Ontario and McMaster Universities Osteoarthritis Index, a questionnaire that asks about how much pain is felt and how well the knee works in daily activities.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Baseline Visit

    You attend the clinic for your first study visit after enrollment. The study staff confirm that you meet all eligibility criteria and explain the study procedures.

    You are randomly assigned to receive either berobenatide or a matching placebo. The assigned medication is a subcutaneous injection (injection under the skin) prepared as a solution for injection.

    The first injection is administered during this visit. You receive written instructions on how the medication will be given each month.

  2. Step 2

    Monthly Injection Visits

    Each month you return to the clinic (or use a pre‑filled pen if instructed) to receive the same subcutaneous injection that you received at baseline.

    The injection contains the dose of berobenatide (or placebo) that was assigned to you at the start of the study. The dose is given once every month for a total of 12 months.

    During each visit you are asked about any side effects and any changes in your health since the previous visit.

  3. Step 3

    Routine Assessments

    At scheduled intervals (typically at weeks 4, 12, 24, 36, and 52) you complete the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale questionnaire, which measures the level of knee pain you experience.

    You also complete the WOMAC physical function subscale questionnaire, which evaluates how knee pain affects your daily activities.

    Your body weight is measured at each assessment visit to track any changes over the course of the study.

  4. Step 4

    Final Study Visit

    At week 52 you attend the last study visit. The final monthly injection of berobenatide (or placebo) is given.

    You complete the final WOMAC pain and physical function questionnaires and have your weight measured one last time.

    The study staff perform a safety evaluation, which includes checking for any adverse events that may have occurred during the 12‑month treatment period.

Who can join the trial?

4 criteria

  • Be at least 18 years old.
  • Have a body mass index (BMI) of 27 or higher at screening – BMI is a number that compares your weight to your height.
  • Feel pain in the selected knee for more than 12 weeks before the screening visit and have pain on at least 15 days during the last 4 weeks.
  • Currently meet the American College of Rheumatology (ACR) criteria for knee osteoarthritis, which are doctor‑approved guidelines used to confirm this joint condition.

Who cannot join the trial?

7 criteria

  • Having a diagnosis of any form of diabetes – a condition where the body cannot properly control blood sugar levels.
  • Reporting a body weight change (gain or loss) of more than 5% in the 90 days before screening – meaning a noticeable shift in weight over the past three months.
  • Having a history of acute or chronic pancreatitis – inflammation of the pancreas that can be sudden (acute) or long‑lasting (chronic).
  • Having a personal or family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia type 2 (MEN‑2) – a specific type of thyroid cancer or an inherited condition that can cause tumors in several glands.
  • Having any other joint disease in the index knee besides osteoarthritis – any additional knee condition in the knee being studied.
  • Having had a prior joint replacement in the index knee – previous knee replacement surgery in that knee.
  • Having received joint injections in the index knee within the last 90 days or any other joint procedures (such as surgery) in the past 6 months.
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Investigated drugs

Berobenatide is an experimental medicine being tested to see if it can reduce knee pain caused by osteoarthritis in adults who are overweight or obese. In the study, it is given as a liquid that is injected under the skin (subcutaneous injection) once each month. The researchers are checking whether this medication works better than a placebo in easing pain and improving knee function.

What is already known about the treatment

Berobenatide - It is supplied as a clear solution for subcutaneous injection, typically administered with a pre‑filled pen or vial. The product is still investigational and is currently being evaluated in Phase 3 clinical trials, so it has not yet received regulatory approval. It is being studied to reduce pain and improve function in adults with knee osteoarthritis who are overweight or obese. Berobenatide is a synthetic peptide that binds to specific receptors on joint cells, helping to lower inflammation and protect cartilage, and it is classified as a peptide disease‑modifying osteoarthritis drug.

Investigated diseases

  • Knee osteoarthritis

    A chronic condition in which the cartilage that cushions the knee joint gradually breaks down, causing the bones to rub together. This loss of cartilage leads to pain, stiffness, and reduced ability to move the joint. Over time the joint may develop bone spurs and the space between the bones can narrow, worsening the symptoms.

  • Overweight and obesity

    A condition characterized by excess body fat that accumulates over months to years. The amount of fat can increase gradually as energy intake exceeds expenditure, leading to higher body weight. As the excess weight builds, it can become more difficult to lose and may progress to higher categories of obesity.

Trial detailsLast updated 12 Nov 2026
Age18+ yearsPhasePhase IIITrial ID2026-526328-34-00Protocol codeC6491022Estimated enrolment667 patientsSponsorPfizer Inc.

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