Cystinosis: improving medicines to help children follow their treatment plan

Cystinosis is an extremely rare condition that is usually diagnosed before a child turns two years old. A medicine called cysteamine can help prevent progressive damage to their organs, including the kidneys and eyes. However, the capsules are foul-smelling and cause unpleasant side effects like sickness and bad breath – and must be taken every six hours. Dr Oisín Kavanagh of Newcastle University is working to create new versions of this drug, which are less challenging to take. His goal is to make it easier for children to stick to their treatment plan – slowing disease progression and improving the quality of life for young patients.

This project is jointly funded by Action Medical Research and LifeArc.

How are children’s lives affected now?

Cystinosis is caused by a build-up of cystine, one of the building blocks of proteins, in cells. This leads to the formation of cystine crystals in many organs, especially in the kidneys and eyes, causing progressive damage over time.

“Without treatment, most children with cystinosis develop kidney failure before age 10, requiring dialysis or a kidney transplant,” says Dr Kavanagh. “Cystine crystals in the eyes cause light sensitivity and pain – and may lead to blindness.”

A medicine called cysteamine can help lower cystine levels, preventing or delaying organ damage. However, if it is not taken regularly, cystine will start to build up – requiring the child to be woken at night to take their medicine, disrupting their sleep.

“Cysteamine is a lifelong treatment, but children often struggle to take it correctly, especially as they get older,” says Dr Kavanagh. “The capsules smell and taste of rotten eggs, causing nausea and sickness – and the breakdown of the drug causes bad breath.”

How could this research help?

“Our goal is to create new versions of cysteamine that help children to follow their treatment plan more easily, leading to improved outcomes,” says Dr Kavanagh.

The team is using a technique called crystal engineering to make a form of the medication that does not smell and releases the drug more slowly, making it easier for children to take, with fewer daily doses, and helping to reduce bad breath.

“We’ve already created several crystal forms of the drug and we will now carry out more laboratory tests to refine these initial versions,” says Dr Kavanagh. “We hope this process will lead us to drug candidates that are ready for future clinical trials.”

As well as the oral tablets, the researchers want to make a formulation that can be applied directly to the eyes. They hope these new versions will be cheaper and longer-lasting than current medications.

“As the safety and effectiveness of cysteamine is already well-established, this should make it quicker and easier for these new formulations to be approved for use in patients,” says Dr Kavanagh.

We do not provide medical advice. If you would like more information about a condition or would like to talk to someone about your health, contact NHS Choices or speak to your GP.