MHRA Approves Dojolvi for Long-Chain Fatty-Acid Disorders

The UK's Medicines and Healthcare products Regulatory Agency (MHRA) approved Dojolvi (triheptanoin) on 30 October 2026, giving NHS patients a second route to a therapy the FDA cleared more than six years earlier. The authorisation covers adults and children with long-chain fatty acid oxidation disorders (LC-FAOD), a group of rare inherited conditions in which the body cannot properly break down certain dietary fats for energy. It arrives conditional, not final: Ultragenyx, the authorisation holder, must still deliver efficacy and safety data from an ongoing paediatric study before the product can convert to a full UK licence.

What LC-FAOD is, and why an energy source counts as treatment

Long-chain fatty acid oxidation disorders are a group of rare, genetically inherited metabolic conditions. People with LC-FAOD lack a functioning enzyme needed to break down long-chain fats into usable energy, particularly during fasting, illness or exertion, when the body would normally turn to fat stores. The consequences can include dangerously low blood sugar, muscle breakdown, and cardiomyopathy. Triheptanoin is a synthetic, odd-chain triglyceride: once absorbed, it is metabolised into compounds that can refill the energy-producing citric acid cycle through a different route than long-chain fats require, giving the body usable fuel its own metabolism cannot otherwise supply. It is administered as an oral liquid, mixed with food or taken directly, and functions as a dietary source of calories and fatty acids rather than a drug that corrects the underlying enzyme defect.

A conditional authorisation, not a final one

The MHRA's approval is explicitly conditional. Ultragenyx's marketing authorisation depends on the company later supplying additional efficacy and safety data from a paediatric study that is still under way; only then does the authorisation convert to a full one. Conditional marketing authorisations are the UK's mechanism for giving patients earlier access to therapies for serious or rare conditions where the full evidence package is not yet complete, in exchange for a binding commitment to finish generating it. The agency's own statement frames the trade-off directly: enabling patient access to high-quality, safe and effective medical products matters to the MHRA, and it will keep triheptanoin's safety under close review as that evidence accumulates. Reported common side effects include stomach pain, diarrhoea and vomiting.

Six years behind the FDA, and what that gap means

Triheptanoin's UK approval lands more than six years after the FDA cleared Dojolvi, on 30 June 2020, as a source of calories and fatty acids for pediatric and adult patients with molecularly confirmed LC-FAOD — the first FDA-approved therapy for the disorder. Health Canada has separately authorised the product, judging its benefit-harm-uncertainty profile favourable for the same indication. For a therapy with no real substitute — LC-FAOD has no other targeted treatment, only dietary management and avoidance of fasting — a multi-year gap between US and UK availability is the kind of asymmetry that rare-disease advocates have pushed regulators to close. The conditional structure the MHRA used here lets it approve without waiting for Ultragenyx to complete a UK-specific paediatric dataset from scratch, leaning instead on the accumulated US and Canadian experience while that final study reads out.

Frequently asked questions

What did the MHRA approve on 30 October 2026?

A new UK marketing authorisation for Dojolvi (triheptanoin) oral liquid, for adults and children with long-chain fatty acid oxidation disorders (LC-FAOD). The authorisation holder is Ultragenyx Netherlands B.V.

Is this a full approval?

No. It is a conditional marketing authorisation. Ultragenyx must still supply further efficacy and safety data from an ongoing paediatric study before it converts to a full authorisation.

Has Dojolvi been approved anywhere else?

Yes. The FDA approved it on 30 June 2020 for pediatric and adult patients with molecularly confirmed LC-FAOD, and Health Canada has authorised it for the same population.

What happens next?

The MHRA will keep the product's safety under close review, and its Summary of Product Characteristics and Patient Information Leaflet are due on the MHRA's products website within seven days of approval. Full UK authorisation depends on the outstanding paediatric study data.