Efficacy and Safety of neoadjuvant stereotactic body radiotherapy plus adebrelimab and chemotherapy for triple-negative breast cancer: A pilot study

Abstract

AbstractBackgroundEmerging data have supported the immunostimulatory role of radiotherapy, which could exert a synergistic effect with immune checkpoint inhibitors (ICIs). With proven effective but suboptimal efficacy of ICI and chemotherapy in triple-negative breast cancer (TNBC), we designed a pilot study to explore the efficacy and safety of neoadjuvant stereotactic body radiotherapy (SBRT) plus adebrelimab and chemotherapy in TNBC patients.MethodsTreatment-naïve TNBC patients received two cycles of intravenous adebrelimab (20mg/kg, every 3 weeks), and SBRT (24Gy/3f, every other day) started at the second cycle, then followed by six cycles of adebrelimab plus nab-paclitaxel (125 mg/m2on days 1 and 8) and carboplatin (area under the curve 6 mg/mL per min on day 1) every 3 weeks. The surgery was performed within 3-5 weeks after the end of neoadjuvant therapy. Primary endpoint was pathological complete response (pCR, ypT0/is ypN0). Secondary endpoints included objective response rate (ORR), residual cancer burden (RCB) 0-I and safety.Results13 patients were enrolled and received at least one dose of therapy. 10 (76.9%) patients completed SBRT and were included in efficacy analysis. 90% (9/10) of patients achieved pCR, both RCB 0-I and ORR reached 100% with 3 patients achieved complete remission. Adverse events (AEs) all-grade and grade 3-4 occurred in 92.3% and 53.8%, respectively. 1 (7.7%) patient had treatment-related serious AEs. No radiation-related dermatitis or death occurred.ConclusionsAdding SBRT to adebrelimab and neoadjuvant chemotherapy led to a substantial proportion of pCR with acceptable toxicities, supporting further exploration of this combination in TNBC patients.FundingThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Clinical trial numberNCT05132790.