Fovinaciclib Plus Aromatase Inhibitors and Dual HER2 Blockade in a Response-Adapted Neoadjuvant Strategy for HR-Positive/HER2-Positive Early Breast Cancer

This prospective, response-adapted phase II study evaluates the efficacy and safety of neoadjuvant fovinaciclib in combination with aromatase inhibitors and dual HER2 blockade in patients with HR-positive/HER2-positive early breast cancer. All patients initially receive induction treatment with fovinaciclib plus endocrine therapy and HER2-targeted therapy, followed by early assessment of treatment response after 6 weeks of treatment. Patients demonstrating an adequate response continue the same regimen, whereas those with a suboptimal response are transitioned to standard neoadjuvant chemotherapy combined with HER2-targeted therapy prior to surgery. This adaptive approach aims to optimize treatment selection, improve therapeutic efficacy, and reduce unnecessary chemotherapy exposure.