This is a single arm, open label, phase 2 trial aimed to investigate the biological effects and safety of pyrotinib combined with trastuzumab, dalpiciclib and letrozole for HR+/HER2+ breast cancer. A total of 30 patients with stage II-III HR+/HER2+ breast cancer will be enrolled. Subjects will be enrolled and receive two cycles of pyrotinib combined with trastuzumab, dalpiciclib and letrozole. Imaging evaluation was performed two weeks later, and patients who achieved CR or PR were continued with the original regimen for 4 cycles. Subjects who did not achieve PR switched to regimen and received 4 cycles of pyrotinib combined with trastuzumab plus chemotherapy. In a specific medication cycle, patients use dalpiciclib orally, 125mg, day 1-21, and letrozole orally, 2.5 mg, day 1-28, and pyrotinib orally, 320mg, day 1-28, and trastuzumab, injection, 8 mg/kg loading dose in cycle 1, 6mg/kg in cycles 2-6, intravenous drops, 1 cycle on day 1-21. Premenopausal or perimenopausal patients should combine ovarian function suppression, including bilateral oophorectomy or treatment with gonadotropin-releasing hormone agonists. The primary endpoint is pathological complete response rate. The secondary endpoints include overall response rate, breast-conserving surgery rate and safety profile.
In this single arm, open label, phase 2 trial, operable patients with stage II-III HR+/HER2+ breast cancer will be enrolled and receive two cycles of pyrotinib combined with trastuzumab, dalpiciclib and letrozole. Imaging evaluation was performed two weeks later, and patients who achieved CR or PR were continued with the original regimen for 4 cycles. Subjects who did not achieve PR switched to regimen and received 4 cycles of pyrotinib combined with trastuzumab plus chemotherapy. This study aims to assessed the biological effects and safety of pyrotinib combined with trastuzumab, dalpiciclib and letrozole for HR+/HER2+ breast cancer in the neoadjuvant setting.