EU clears brain disease pill for boys

Picture a boy who runs, reads and plays like any other child, yet a routine MRI finds a small patch of damage in his brain. For boys with cerebral adrenoleukodystrophy, a rare inherited brain disease, that finding can now lead to treatment. On 21 September the European Commission authorised Nezglyal (leriglitazone), a medicine taken by mouth, for this early stage (EMA).

Why doctors scan boys who seem well

The disease starts with a faulty gene called ABCD1. Normally it helps cells get rid of a type of very long fat molecule, and without it those fats build up (consensus).

Carrying the faulty gene does not tell a family when the brain will become inflamed, and doctors still don't know what triggers that phase. Once it begins, inflammation attacks white matter, the insulated wiring that links brain regions, and a boy can decline fast (disease review).

So doctors watch closely. International guidance recommends a first MRI at age two, scans every six months until 12, and yearly scans after that (guidance).

Those scans often include an injected dye called gadolinium. A protective barrier usually keeps it out of brain tissue. Where inflammation is active, that barrier can leak at the lesion's edge, and the dye seeps through and lights up, like damp spreading along a crack in a wall.

A lesion that doesn't light up is visible but shows no sign of that leak. It is often an earlier stage, though how it develops varies from boy to boy. This is the group Nezglyal targets.

The label covers boys aged two to 12 with this kind of non-enhancing lesion and little or no neurological impairment (EMA). The established treatment for early brain disease, a stem-cell transplant, can halt progression but cannot reverse damage, carries serious risks, and remains an option for eligible patients (consensus). Nezglyal adds a pill to that choice.

Seven boys out of twenty

The evidence comes from NEXUS, a study that gave leriglitazone to 23 boys without an untreated group for comparison (NEXUS registry). Of the 20 boys with enough data, seven, or 35%, reached what the study called "disease arrest" (EMA).

Arrest meant a boy stayed stable on both clinical checks and MRI through the study period, or until he moved on to a transplant. It describes a pause in the disease, not a repaired brain.

Is 35% good? Records of untreated boys suggest roughly 10% would reach that point anyway (EMA). Comparing with past records is shakier than following two groups side by side, because the children who enrolled may differ from those in the records.

The split inside the result explains the narrow label. According to Medscape, six of nine boys with non-enhancing lesions reached arrest, compared with one of 11 whose lesions already lit up. The numbers are small, but the pattern points toward the earlier stage.

Reported side effects include weight gain, swollen eyelids and lower white-blood-cell counts (EMA). Rare or late harms cannot be judged from so few children.

The approval followed an earlier refusal of a broader claim, after which a new file built on the paediatric data won over regulators (pharmaphorum). The authorisation came "under exceptional circumstances", a route for very rare diseases where full data are hard to gather. It requires further safety data, a registry tracking long-term effectiveness and yearly updates (EMA).

From a Spanish lab to a German pharmacy

The medicine grew out of public research. According to El País, Aurora Pujol's group at IDIBELL-CIBERER found in 2010 that a related drug, pioglitazone, reduced brain inflammation in mice, and the institute licensed the patent to Minoryx, a company in Mataró that designed leriglitazone to reach the brain better (El País).

EU approval does not put the drug on shelves. Minoryx and its commercial partner forecast a first launch in Germany before the end of 2026, with other markets following price talks (announcement). Each country still decides whether to supply and pay for it.

Even in the country where it was invented, access is unsettled. El País describes a Spanish child treated for about three years through compassionate use, meaning case-by-case access before approval, but no Spanish public-funding decision has been confirmed (El País).

The label turns a scanning schedule into the gateway to treatment. Nezglyal can only help boys whose lesions are spotted at the non-enhancing stage, so its value in each country will depend on diagnosed boys getting their regular MRIs on time. Minoryx's registry and EMA's required follow-up now have to show whether the stability seen in a handful of children lasts.