Finerenone: the first drug in decades to protect kidneys in Type 1 diabetes

What the trial measured, and what it did not

Finerenone blocks the receptors the hormone aldosterone acts on in the kidneys, heart and blood vessels, which is meant to slow the inflammation and scarring that damage kidneys over years. FINE-ONE was a Phase 3 trial, the stage a medicine reaches just before its maker asks regulators to approve it. It gave finerenone or a dummy tablet to 242 adults with Type 1 and chronic kidney disease, on top of whatever they were already taking, and followed them for six months across 82 hospitals in nine countries. Bayer, which makes the drug, funded it.

What it measured was the urine albumin to creatinine ratio (ACR): how much albumin, a protein, is leaking through the kidney filters into urine. Over six months, ACR fell about 25% further on finerenone than on the dummy tablet. That is a marker of kidney damage, not a hard outcome. Nobody was followed long enough to show fewer people needing dialysis or a transplant, and average kidney filtering rate actually dipped a little more in the finerenone group over those six months. A short study of a marker is a reason to keep going, not a finished answer.

Type 1 has been left out of kidney medicine for a long time

Kidney trouble is not rare in Type 1. Breakthrough T1D says nearly one in three people with Type 1 develop kidney disease at some point, and Diabetes UK says almost one in five people with diabetes will need treatment for it. Yet the drugs that protect kidneys in Type 1 today, ACE inhibitors and ARBs, are blood pressure tablets whose kidney evidence goes back to the 1990s. Everyone in FINE-ONE was already on one of them, so this was a benefit on top of that, not instead of it.

Almost everything newer has been tested and licensed in Type 2 diabetes instead. Finerenone is itself an example: its UK licence covers chronic kidney disease with Type 2 diabetes, and NICE recommends it for that group, not for Type 1. Dapagliflozin tells a similar story, licensed for Type 1 in the UK and then withdrawn for that use in 2021, which Diabetes UK said was not down to any safety problem. A trial built around Type 1 from the start is unusual, and that is much of why this one matters.

What would have to happen before the NHS could offer it

Two separate gates, and neither is quick. First the licence: a medicine is normally prescribed only for what sits on its marketing authorisation, so the MHRA would have to agree to add chronic kidney disease in Type 1 diabetes to the UK licence for finerenone. Bayer has said it intends to put the data to health authorities for exactly that assessment.

Then the funding: NICE decides whether the NHS in England should pay for a medicine for a particular group, the Scottish Medicines Consortium does the same job in Scotland, and a new group normally means a fresh appraisal. If regulators do agree, reporting from the conference where the results were first shown framed it as the first treatment approved for this group in about 30 years. Until then, the honest position is that finerenone is not a Type 1 treatment in the UK, and your team is working with what is licensed today.

What varies from person to person

FINE-ONE recruited a narrow group, not everyone with Type 1. People needed a clearly raised urine ACR that had been there for months, an eGFR between 25 and just under 90, and at least four settled weeks on an ACE inhibitor or an ARB. Anyone recently on an SGLT2 inhibitor or a GLP-1 medicine was left out. So the result does not automatically carry over to someone whose ACR is normal, or whose kidney disease is much further along. Your own picture comes from your annual results and what your team makes of the trend in them.

Worth paying attention to

Questions that make an appointment useful

Similar articles