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RecruitingPhase IIIInterventional

Implementation of Metformin theraPy to Ease DEcline of kidney function in Polycystic Kidney Disease (IMPEDE-PKD): randomised placebo-controlled trial

The IMPEDE-PKD study is investigating if metformin, a safe and widely used diabetes medication, can help protect kidneys in people with Autosomal Dominant Polycystic Kidney Disease (ADPKD). ADPKD causes fluid-filled sacs (cysts) in the kidneys, leading to kidney damage over time. Currently, there's only one main treatment for ADPKD which isn't suitable for everyone. This study will involve people aged 18-70 with ADPKD taking either metformin or a dummy tablet daily for two years. Researchers will monitor their kidney health to see if metformin slows down cyst growth and kidney decline. It aims to find a new, accessible treatment option for this condition.

At a glance

Status
Recruiting
Phase
Phase III
Sponsor
Sheffield Teaching Hospitals NHS Foundation Trust
Enrolment target
1,174
Start
13 Nov 2025
Estimated completion
30 Sep 2028

What is this study about?

Autosomal Dominant Polycystic Kidney Disease, or ADPKD, is a condition you inherit that causes problems with your kidneys. In ADPKD, sacs filled with fluid, called cysts, grow inside your kidneys. Over time, these cysts get bigger and can damage the healthy parts of your kidneys, making it harder for them to clean your blood properly. Many people with ADPKD eventually need treatments like dialysis or a kidney transplant to stay healthy.

At the moment, there's only one specific medicine for ADPKD, but it doesn't work for everyone and can have tricky side effects. This is why researchers are looking for other options. Metformin is a well-known drug that has been safely used for many years to treat diabetes. Recent studies suggest that metformin might be able to slow down the growth of those kidney cysts. This trial aims to check if metformin can indeed keep kidneys working better for longer in people with ADPKD.

Taking part in this study means helping doctors understand if metformin can offer a new and affordable way to manage ADPKD. While it can't be guaranteed that you'll directly benefit, the information gathered from participants will be crucial for developing better treatments for ADPKD patients in the future.

Key takeaways

  • The study explores if metformin can slow kidney disease in ADPKD.
  • Metformin is a common, safe diabetes drug that might help reduce kidney cysts.
  • Participants will take tablets daily for two years after an initial adjustment phase.
  • The study involves regular check-ups, blood tests, and questionnaires.
  • This research aims to find a new, accessible treatment for ADPKD.
  • The study is for adults aged 18-70 with specific ADPKD characteristics.

Who may be eligible?

This study is looking for adults with ADPKD who are between 18 and 70 years old. You need to have been diagnosed with ADPKD, and your kidney function (as measured by something called eGFR) should be within a specific range – not too good, but not too poor either. If you are already taking another ADPKD medication called tolvaptan, you’ll need to have been on a steady dose for at least three months.

To be considered for the study, your ADPKD needs to show certain signs that it's progressing or might progress in the future. This could be based on the size of your kidneys or how quickly your kidney function has changed over time. Don't worry, the study team will help you understand if these specific criteria apply to you.

There are also some reasons why you might not be able to join. For example, if you have diabetes, very high blood pressure that isn't controlled, or certain heart conditions, you wouldn't be able to take part. Women who are pregnant, breastfeeding, or planning to get pregnant in the next three years also cannot join because pregnancy can affect kidney measurements and the trial medication.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

  1. Are you between 18 and 70 years old?
  2. Do you have a diagnosis of ADPKD?
  3. Is your kidney function (eGFR) within a certain range (the study team can check this)?
  4. If you're on tolvaptan, have you been on a stable dose for at least 3 months?
  5. Do you have signs that your ADPKD is progressing or at high risk of progressing (the study team can assess this)?
  6. Are you able to use highly effective contraception if you are a woman who could become pregnant, and not planning pregnancy for three years?
Answer every question to see your result.

What does participation involve?

If you decide to take part, the study will last about 27 months in total. First, there's a 12-week 'run-in' phase. During this time, everyone will take metformin for 10 weeks to find the best dose that suits them. For the last two weeks of this phase, you'll stop all medication.

If you manage the run-in phase well, you'll then be randomly put into one of two groups for the main part of the study. One group will take metformin every day for two years, and the other group will take a 'dummy' tablet (a placebo) that looks the same but contains no active medicine. You won't know which one you're taking. Throughout the study, you'll have regular hospital visits, which may include questionnaires, blood and urine tests, blood pressure checks, and physical examinations. The study team has tried to make these visits fit with your normal clinic appointments where possible. You might also have some phone appointments. You may be reimbursed for your travel costs. Most of the time, you can carry on with your usual daily life.

Potential risks and benefits

While we can't promise that this study will directly improve your health, the information we learn will be very important for helping people with ADPKD in the future. Like all medicines, metformin can have side effects, such as tummy upsets like diarrhoea and bloating. These often settle down after a few weeks, especially if taken with food. The study team will help manage any side effects, including adjusting your dose if needed. There will be extra hospital visits, and blood tests might cause some temporary discomfort. Women who could become pregnant will need to use effective contraception throughout the study and for some time after and cannot plan to get pregnant for three years. You are free to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (23)

  • Northern General Hospital
    Approximate
    Sheffield, England
  • Norfolk & Norwich University Hospital
    Approximate
    Norwich, England
  • Royal Devon and Exeter Hospital
    City only
    Exeter, England
  • Kings College Hospital
    Approximate
    London, England
  • Churchill Hospital
    Approximate
    Oxford, England
  • Salford Royal Hospital
    Approximate
    Salford, England
  • Royal Free Hospital
    Approximate
    London, England
  • The Royal London Hospital
    Approximate
    London, England
  • University Hospital Birmingham
    Approximate
    Birmingham, England
  • Freeman Hospital
    Approximate
    Newcastle upon Tyne, England
  • Nottingham City Hospital
    Unverified
    Nottingham, England
  • Royal Stoke University Hospital
    Unverified
    Stoke-on-trent, England

Common questions

What is ADPKD?

ADPKD is an inherited kidney condition where fluid-filled sacs (cysts) grow in your kidneys, damaging them over time.

What is metformin?

Metformin is a common and safe medication that has been used for many years to treat diabetes. We're now studying if it can help ADPKD.

How long will the study last?

The study will last about 27 months in total, including an initial 12-week phase and then two years of taking study medication.

Will I know if I'm taking the real drug or a dummy pill?

No, you won't know whether you're taking metformin or a placebo (dummy pill). This helps ensure fair and accurate results.

What kind of tests will I have?

You'll have blood and urine tests, blood pressure checks, physical exams, and complete some questionnaires at regular visits.

How to find out more

Megan Jones

Always speak to your GP or specialist before deciding to take part in a study.

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