Novel HER2-Directed Antibody Drug Conjugate Shows Promise in the Neoadjuvant Setting for HER2-Positive Breast Cancer
Results from a phase 2 study found that SHR-A1822, a novel third generation HER2-directed antibody-drug conjugate, showed promise in the neoadjuvant setting for patients with HER2-positive breast cancer.
These results will be presented by Junjie Li, MD, Fudan University, Shanghai, China, at the 2024 San Antonio Breast Cancer Symposium.
In this open-label phase 2 trial, 265 patients with HER2-positive breast cancer were randomized on a 1-to-1-to-1 basis to receive nab-paclitaxel plus carboplatin with trastuzumab and pertuzumab for 6 cycles (n = 90), 4.8 mg/kg intravenously of SHR-A1811 monotherapy on day 1 every 3 weeks (n = 87), or SHR-A1811 plus 240 mg orally once daily of pyrotinib (n = 88) for 8 cycles. The primary end point for this study was pathological complete response (pCR) among all randomly assigned patients in the intention-to-treat population.
The pCR rate among patients in the nab-paclitaxel plus carboplatin with trastuzumab and pertuzumab arm was 66%. The pCR rate among those in the SHR-A1811 monotherapy arm was 63% and 62% in the SHR-A1811 plus pyrotinib arm. There was no statistical difference between each group. There was 1 patient with grade 2 interstitial lung disease in the SHR-A1811 monotherapy arm. In the SHR-A1811 plus pyrotinib arm, 9% of patients experienced grade 3 diarrhea. There were no treatment-related deaths.
Study authors wrote, “this is the first study to report the efficacy of third generation HER2-direct [antibody-drug conjugates) in the neoadjuvant setting of HER2-positive breast cancer.” They concluded, “SHR-A1811 exhibited promising antitumor activity and acceptable tolerability.”
Source:
Li J. HER2-directed antibody-drug conjugate SHR-A1811 in the neoadjuvant treatment of HER2-positive early breast cancer: A prospective, randomized, open-label, phase 2 trial. Presented at San Antonio Breast Cancer Symposium. Dec 10-13, 2024; San Antonio, TX. Abstract: SESS738
