Therapy & companion diagnostics

The approval covers a strategy that detects an ESR1 mutation in blood during treatment and switches therapy before disease progression is observed. The important shift is that testing informs decisions during treatment, not just the initial choice of therapy. FDA approval notice ↗

The business question is whether testing expands from a one-off assessment to ongoing monitoring. Its value will depend on payment for repeat tests, turnaround time and how often results lead to a treatment change. We will follow whether this pathway becomes part of routine care, rather than count approvals alone.