RecruitingPhase IIInterventional

Losartan for older adolescents and adults with osteogenesis imperfecta

Osteogenesis imperfecta (OI) is an inherited condition that causes fragile bones that break easily, along with muscle weakness and fatigue. Currently, there are no approved medicines specifically licensed to treat it. Researchers want to see if a widely used blood pressure tablet called losartan can help. Losartan blocks a protein in the body that may weaken bones and muscles in people with OI. In this study, participants aged 16 and older will take a losartan tablet once a day at bedtime for 24 weeks. The study tests three different dose levels to check safety and effectiveness. Doctors will monitor blood pressure, take routine blood tests, and carry out detailed bone scans in Sheffield. Taking part will help researchers learn whether losartan can improve bone health, muscle strength, and everyday quality of life.

At a glance

Status

Recruiting

Phase

Phase II

Sponsor

Sheffield Children's NHS Foundation Trust

Enrolment target

Start

01 Nov 2023

Estimated completion

30 Oct 2026

Osteogenesis imperfecta

What is this study about?

Osteogenesis imperfecta (OI), sometimes called brittle bone disease, is a rare genetic condition affecting around 1 in 16,000 people. People living with OI have bones that can break easily, often from minor bumps or everyday movements. It can also cause muscle weakness, bone curvature, ongoing pain, and deep tiredness. At present, there are no medicines officially approved in the UK to treat OI, and standard bone treatments do not work well for everyone.

Scientists have found that people with OI often have high levels of a body protein called TGF-beta. Too much of this protein seems to speed up bone loss and weaken muscles. Losartan is an existing medicine normally used to treat high blood pressure, but it is also known to lower TGF-beta levels. Researchers hope that by calming this protein down, losartan might help protect bones and boost muscle strength.

This trial is an important step to see if repurposing losartan is safe and helpful for teens and adults with OI. Because losartan is already a well-understood, low-cost medication used by millions worldwide, finding out that it works for OI could quickly lead to new care options for people living with this lifelong condition.

Key takeaways

Tests whether losartan improves bone and muscle health in osteogenesis imperfecta (OI).
Open to people aged 16 and older diagnosed with any type of OI.
Involves taking one tablet daily at bedtime for 24 weeks.
Includes regular blood pressure and blood tests, plus two bone scans in Sheffield.
Travel and hotel expenses for trips to Sheffield are provided.
Taking part is voluntary, and you can leave the study at any time.

Who may be eligible?

This trial is open to people aged 16 and older who have been diagnosed with any type of osteogenesis imperfecta. To take part safely, participants must not be taking other medicines that lower blood pressure, raise potassium levels, or interact with losartan (such as lithium). Women who could become pregnant must agree to use reliable contraception throughout the trial.

Because the researchers need to clearly see the effects of losartan, you cannot join if you currently take standard bone-strengthening treatments, such as bisphosphonates or denosumab. If you have taken these in the past, you may still be able to join if you only had a short course or a single dose and finished it at least six months ago.

You also will not be able to participate if you have severe low blood pressure, high blood potassium levels, severe liver or kidney disease, or if you have used losartan within the past six months.

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.

I am aged 16 or older.
I have been diagnosed with osteogenesis imperfecta (brittle bone disease).
I am not currently taking losartan or other blood pressure medicines.
I am not currently taking regular bone medications (like bisphosphonates).
I do not have severe kidney disease, liver disease, or known high potassium levels.
I am willing to attend regular monitoring appointments and travel to Sheffield twice for scans.

Answer every question to see your result.

What does participation involve?

Taking part in this study lasts for about 24 weeks. You will be asked to take one losartan tablet every evening right before bed. Everyone starts on the lowest dose (25 mg). Depending on which group you are randomly placed into, your dose may stay the same or be carefully increased to 50 mg or 75 mg over time.

You will attend clinic visits to check your blood pressure and have routine blood samples taken. These tests make sure the medicine is safe for you and that your blood potassium levels remain normal. You will also have specialised, high-detail bone scans. These special scans take place at a centre in Sheffield at two points during the study. If you live outside Sheffield, your travel, food, and accommodation costs for these trips will be covered.

Potential risks and benefits

You might experience better muscle function or bone strength from taking part, but this cannot be guaranteed as this is a research study. However, your participation will help doctors learn whether losartan can help others with brittle bone disease in the future. The main risks are related to losartan's normal effects, such as a drop in blood pressure causing light-headedness, or a rise in blood potassium. Taking the tablet at bedtime and having regular clinic checks helps keep you safe. Having blood taken may cause brief discomfort or slight bruising. Remember, joining is entirely voluntary, and you are free to stop taking part at any time without your regular NHS care being affected.

Locations (8)

Sheffield Children's Hospital
Approximate
Sheffield, England
Northern General Hospital
Approximate
Sheffield, England
Royal National Orthopaedic Hospital
Approximate
Stanmore, England
Sheffield Teaching Hospitals NHS Foundation Trust
City only
Sheffield, England
Aintree University Hospital
Approximate
Liverpool, England
NHS Lothian
Unverified
Edinburgh, Scotland
NHS Grampian
Unverified
Aberdeen, Scotland
NHS Greater Glasgow and Clyde
Unverified
Glasgow, Scotland

Common questions

Why are researchers testing a blood pressure drug for brittle bones?

Losartan lowers blood pressure, but it also lowers a protein called TGF-beta. Scientists believe too much TGF-beta weakens bones and muscles in people with osteogenesis imperfecta.

Will I have to pay to travel to Sheffield for bone scans?

No. If you need to travel to Sheffield for the specialist bone scans, the study team will cover your travel, food, and accommodation costs.

Why must I take the tablet at bedtime?

Taking losartan right before you sleep reduces the chance of feeling dizzy or faint if your blood pressure dips slightly.

Can I stay on my current bone medicines during the study?

No. Most bone medications, like bisphosphonates or denosumab, cannot be taken during the trial because they would make it hard to tell if losartan is working.

What happens if I feel dizzy while taking the medicine?

The study team monitors your blood pressure closely. If you develop dizziness, doctors can lower your dose, recheck your health, or safely stop the medicine if needed.

How to find out more

Mahboobeh Haji Sadeghi

Mahboobeh.HajiSadeghi@hyms.ac.uk +44 (0)1482 464018 Official trial record

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