TROP2 PET to choose and sequence TROP2 ADCs
Use a whole-body TROP2 scan instead of a single tissue stain to decide which patients get a TROP2 ADC, which one, and when to switch.
IHC on archival tissue failed to predict sacituzumab benefit. A PET tracer would capture heterogeneity across lesions, current (not archival) expression, and antigen loss at progression.
For hormone-receptor-positive metastatic breast cancer that has already had chemotherapy, Dato-DXd controls the disease for longer with fewer severe side effects than chemotherapy, but does not help patients live longer, so it is not a standard option here. The result is a reminder that progression-free survival is a surrogate; regulators and clinicians should wait for survival data before adopting an ADC in a setting where later therapies are effective.
Sacituzumab govitecan is a standard second-line or later treatment for metastatic triple-negative breast cancer, roughly doubling survival compared with the chemotherapies it was tested against. Patients should expect neutropenia and diarrhoea, which are manageable with growth factor support and loperamide. Trials are now testing it earlier, in first-line combinations with pembrolizumab and after surgery for residual disease.