The problem with Her2-low testing

The approval this summer of Astrazeneca and Daiichi’s Enhertu for patients expressing low levels of Her2, the antigen against which the drug is targeted, was a huge coup for the partners. In early October Roche received FDA approval for an assay called Pathway anti-Her2 as a companion diagnostic for Enhertu, specifically to identify Her2-low breast cancer patients – the first such accolade.