New daily treatment approved for children and adults with rare inherited energy disorders

Children and adults living with a group of rare inherited disorders that stop the body turning fat into energy now have a new treatment option in the UK, after the medicines regulator approved a daily oral medicine.

The Medicines and Healthcare products Regulatory Agency (MHRA) has approved an oral liquid form of triheptanoin, sold as Dojolvi, to treat long-chain fatty acid oxidation disorders, known as LC-FAOD, in patients of all ages.

What are LC-FAOD?

LC-FAOD are a group of rare genetic conditions. People who have them cannot properly use long-chain fatty acids, found in many foods and stored in the body, as a source of energy.

That matters most when the body needs energy quickly, for example during illness, exercise or going without food. Without enough fuel, patients are at risk of serious events that can lead to frequent hospital stays, including muscle breakdown, damage to the heart muscle and dangerously low blood sugar.

Until now, management has relied heavily on a carefully controlled diet and avoiding long periods without eating.

How the medicine works

Triheptanoin is a liquid taken by mouth every day as part of a carefully controlled diet. The MHRA says it works by helping to prevent energy crises in the body's cells, which can cause the muscle, heart and blood sugar problems linked to the conditions.

It is available only on prescription, and patients should always take it exactly as directed by their healthcare team. The most common side effects, which may affect more than one in ten people, are stomach pain, diarrhoea and vomiting.

"Significant barriers"

Julian Beach, executive director of operations at the MHRA, said: "Enabling patient access to high quality, safe and effective medical products is important to us.

"Patients living with rare diseases often face significant barriers in accessing effective treatments and we're assured that the appropriate regulatory standards for the approval of this medicine have been met.

"As with all products, we will keep the safety of triheptanoin under close review."

A conditional approval

The medicine has been given a conditional marketing authorisation. That means it can be used now, but the company must provide further evidence of how well it works and how safe it is, from a study in children that is still under way, before a full authorisation can be granted. It is a route regulators use to get promising medicines to patients with serious conditions sooner.

Anyone who thinks they are having a side effect from the medicine is encouraged to speak to their doctor, pharmacist or nurse, and to report it through the MHRA's Yellow Card scheme, which can be found online.

Why it matters

Each rare disease affects only a small number of people, but together rare conditions affect many families, including in Birmingham, where specialist hospital teams care for children and adults with inherited metabolic conditions. For those families, every new licensed treatment means more choice and, potentially, fewer emergencies.

Doctors will now be able to consider triheptanoin for eligible patients, alongside the dietary management that remains central to care.