EU regulator withdraws Amgen's Tavneos authorization over serious trial breaches

European regulators have withdrawn the marketing authorization for Amgen's rare disease drug Tavneos, citing serious breaches in the pivotal clinical trial.

The EMA said study staff from ChemoCentryx, which developed Tavneos before Amgen's 2022 acquisition, accessed unblinded efficacy data after the database was locked and found that the drug had not demonstrated superiority at week 52.

Subsequently, nine patients' data were re-adjudicated with knowledge of treatment outcomes, and the primary analysis was rerun, changing the result from non-significant to statistically significant. These changes were not disclosed to regulators, and the clinical study report incorrectly claimed the unblinding protocol had been followed.

The regulator's decision follows Amgen's quiet removal of Tavneos from the market last week and raises concerns about data integrity in the drug's development program.