Global access to management of primary hyperoxaluria: a survey on behalf of OxalEurope, G&K Working Group of the ERA and ESPN.

Background: Primary hyperoxaluria (PH) is a rare disorder with significant morbidity and mortality if left untreated. Given the rarity, global inequities in diagnostics and treatment are expected. Recently introduced RNA interference therapeutics (RNAi) have dramatically changed the outcome for PH patients, potentially disproportionately affecting low-resource regions. Understanding these disparities is crucial for implementing measures to ensure equitable healthcare access for PH patients worldwide. This study aims to evaluate the current global health situation for PH patients upon the introduction of targeted therapeutics.

Methods: An international cross-sectional questionnaire study was conducted among healthcare providers involved in PH care. Responses were gathered between March 2023 and April 2024 and distributed by e-mail via various international nephrology networks. Meta-analysis (mixed random effects model with inverse-variance weighting) was used to analyze data and adjust for subgroup differences.

Results: We gathered 136 responses from 57 countries, representing all World Bank regions. Overall access to genetic analysis diagnostics was 82% (confidence interval 77%-91%) and to urinary oxalate measurement 97% (93%-100%). Significant differences (P < .05) between low- and high-income countries were found for most diagnostics including genetic testing, plasma oxalate, plasma and urinary glycolate. Conservative therapies (e.g. pyridoxine and alkalinizing agents) were highly available globally (98% and 95%), but significant differences in access to peritoneal dialysis, and kidney and liver transplantation were reported (P < .05). Access to the RNAi therapeutic lumasiran was limited to high- and middle-income countries, with 53% (40%-66%) of all countries having access (78% high-income versus 56% middle-income). Even in high-income countries, RNAi was not always accessible.

Conclusions: We found global disparities in access to optimal management of PH patients, disproportionately affecting low-income countries, but even existing between high-income countries. These results may provide support for initiatives to improve the outcome of PH patients worldwide in an era of new targeted therapeutic treatments.