The FDA approved Pfizer and Arvinas’ Veppanu (vepdegestrant) for a defined subgroup of adults with metastatic estrogen receptor-positive, HER2-negative breast cancer whose disease progressed after at least one endocrine therapy, and who have ESR1 mutations. The agency’s decision aligns with efficacy data from the VERITAC-2 trial, where Veppanu improved progression-free survival by nearly three months versus fulvestrant. Arvinas and Pfizer co-developed the PROTAC (proteolysis-targeting chimera) therapy. The approval gives the regimen a clearer regulatory footprint in ESR1-mutated disease after endocrine resistance, a segment where treatment options are limited and clinical endpoints have emphasized durability. Commercially, the label is narrow and tied to ESR1 status, setting up a targeted use profile rather than broad first-line positioning. The approval also adds a new mechanism class to the breast cancer market, reinforcing investor focus on protein-degradation strategies. For diagnostics, the decision increases the practical value of companion-style biomarker testing for ESR1 mutations to identify eligible patients.