Design: prospective real-world national cohort study with 12-month follow-up
Population: 76 patients with primary hyperoxaluria type 1 starting lumasiran, 54 children, 24 on dialysis
Primary outcome: proportion meeting a composite biochemical oxalate response at three months
Effect: 73% responded at three months; no genotype association; younger age at diagnosis and initiation predicted response

The French DAILY-LUMA cohort collected real-world data on 76 patients with primary hyperoxaluria type 1 starting lumasiran, 54 of them children, at a median age of 13 years, with 24 already on dialysis. Response was defined as normalisation or a fall of more than 30% in urinary oxalate to creatinine ratio, or in plasma oxalate for those with an eGFR below 30.

At three months, 73% met the criterion. The hypothesis under test - that genotype, classified by expected vitamin B6 responsiveness, would predict response - was not supported; if anything there was a trend towards poorer response in the B6-sensitive forms. What did predict response was age: younger age at diagnosis and at starting treatment, with the best responses in children.

Two practical points follow. Genotype should not be used to decide who receives lumasiran or to set expectations about response - a reasonable assumption that this cohort does not support. And in pyridoxine-sensitive disease the authors advise continuing or starting pyridoxine even after lumasiran begins, rather than treating the new therapy as a replacement. In India, where primary hyperoxaluria presents late and often with established kidney failure, the age finding is the discouraging one: the patients who respond best are the ones diagnosed before damage accumulates, and late diagnosis is the norm.

Do not use genotype to predict lumasiran response or to select patients.
Continue or start pyridoxine in vitamin B6-sensitive disease after lumasiran begins.
Best responses were in children and in those diagnosed young.
Re-evaluate biochemically at three, six and twelve months rather than assuming sustained response.
Late diagnosis is the main barrier to response in settings where presentation is with kidney failure.

Why it matters

It removes genotype from a decision clinicians were reasonably using it for, and keeps pyridoxine in a regimen many would have stopped.

The statistics, in plain English

A cohort of 76 patients split across three genotype groups leaves small numbers in each, so the absence of a genotype association is weak evidence of no association rather than strong evidence against one. The age finding is more robust because age is continuous and measured in everyone. Response here is also a biochemical composite, not a clinical outcome such as kidney survival.