Assessing the Chiral Switch: Approval and Use of Single-Enantiomer Drugs, 2001 to 2011

From 2001 to 2011, the FDA approved 9 single-enantiomer drugs as chiral switches, yet only 3 had preapproval trials directly comparing them to their racemic precursors, and none demonstrated superior efficacy at comparable doses. Meanwhile, Medicaid spent approximately $6.3 billion on these products during this period. The findings suggest that chiral switches are often approved and widely adopted without robust evidence of clinical superiority over existing racemic formulations, raising questions about the drug approval process.