The roxadustat wrangling rumbles on

Fibrogen and partners were probably hoping that the long-awaited cardiovascular safety analysis of the huge roxadustat clinical programme would silence concerns. But another highly critical report emerged yesterday; the authors are probably positioned to benefit from falling share prices, but it is notable that both Fibrogen and Astrazeneca moved to defend their data. The report concluded that roxadustat was unlikely to win approval in dialysis-dependent patients, pointing out that Pyrenees, a major trial that had the worst safety reading, had been omitted from the pooled analysis; it also claimed that the way the data were analysed understated the risk of death in this setting. Astrazeneca responded by saying the FDA had agreed to the Pyrenees exclusion, because of its different design; supportive equity analysts moved to defend other assertions of opaqueness. The sellside remains largely approving of Fibrogen, but roxadustat forecasts have come down substantially over the past 12 months. None of these debates will be settled until the regulatory verdicts are known, later next year, and until then many investors might decide to believe that there is no smoke without fire. Substantial postmarketing requirements are surely the best-case scenario here.