The Food and Drug Administration's (FDA) drug review arm has proposed withdrawing approval for Amgen Inc.’s (NASDAQ:AMGN) Tavneos (avacopan), citing concerns over data integrity, lack of proven effectiveness, and misleading statements in its application.

Amgen added Tavneos to its portfolio via the ChemoCentryx deal in 2022 for $52 per share in cash, representing an enterprise value of approximately $3.7 billion.

FDA Flags Data Integrity Issues

The Center for Drug Evaluation and Research (CDER) said new information revealed that key data supporting Tavneos' approval was manipulated.

The agency found that unblinded study personnel altered endpoint results in the Phase 3 ADVOCATE trial, the sole study used to establish the drug's effectiveness.

In a letter to the company, CDER highlighted that manipulation changed outcomes that were not statistically significant, making the drug appear effective.

The original analysis, conducted under a ...