Calliditas sets the bar for its kidney disease rivals

Calliditas’s Tarpeyo was the first treatment to gain accelerated approval for the rare kidney disease IgA nephropathy, based on reductions in the biomarker proteinuria. Now the drug has become the first to show a benefit on the hard outcome of estimated glomerular filtration rate (eGFR), a vital step towards full approval. Calliditas’s stock shot up 37% today, but given the solidifying link between proteinuria and eGFR the group might not be able to claim its unique status for much longer. Travere is expecting eGFR data this year on Filspari, which gained accelerated approval last month. That product, and others, have shown stronger proteinuria reductions than Tarpeyo, the table below shows – although some players, like Novartis, have pressed on with less impressive data. For now, though, Calliditas will be celebrating its head start. The topline results come from part B of the Nefigard study, which measured eGFR at two years, after nine months of Tarpeyo therapy and 15 months' follow-up. It found a mean reduction in eGFR of 2.47ml/min/1.73m² with Tarpeyo versus 7.52ml/min/1.73m² with placebo. Now it is over to the group’s many IgAN rivals to see whether they can clear the bar Calliditas has set.