Abstract P2-14-08: Preliminary safety and efficacy results of camrelizumab in combination with apatinib and eribulin in heavily pretreated patients with advanced triple-negative breast cancer: A phase II trial

Abstract

Abstract Background: Our prior phase II trial (NCT03394287) demonstrated that camrelizumab (an anti-PD-1 antibody) combined with apatinib (an anti-VEGFR2 tyrosine kinase inhibitor) showed a favorable objective response rate (ORR) of 43% in treating patients with advanced triple-negative breast cancer (TNBC), even in those with PD-L1-negative tumors and received 1-2 lines of chemotherapy. However, the progression-free survival (PFS) and overall survival (OS) remained short. Since EMBRACE trial and 301 study found that eribulin monotherapy significantly prolonged OS with relatively low toxicities than other common chemotherapy drugs as multi-line therapy in the treatment of advanced breast cancer, especially for patients with TNBC, we have conducted a phase II trial to study the efficacy and safety of combinational treatment of camrelizumab, apatinib, and eribulin in patients with heavily pretreated advanced TNBC. Methods: Female patients with advanced TNBC who were previously treated with at least one line of systemic therapy were enrolled from three academic hospitals in China to receive camrelizumab 200mg (iv. 3mg/kg for the patient whose weight is below 50kg) on day 1, and apatinib 250mg daily (po, d1-d21), plus eribulin mesylate at 1.4 mg/m2 (iv.) on days 1 and 8 of a 21-day cycle until progression, unacceptable toxicities or patient withdrawal. The primary endpoint was ORR according to RECIST v1.1. Secondary endpoints included disease control rate (DCR), clinical benefit rate (CBR), PFS, time to response (TTR), duration of response (DoR), 12-months OS, toxicities, and potential biomarkers. Results: From March 2020 to May 2021, 46 patients were enrolled. 13 of 46 patients (28.3%) received ≥3 lines of chemotherapy in the advanced setting. And 8 of 46 patients (17.4%) had received PD-1/PD-L1 blockade combined with chemotherapy in the previous treatment for advanced disease. Until May 31th, 2021, 39 and 46 patients were evaluable for overall response and safety, respectively. The ORR was 40.0% (16 of 40, 95% CI: 24.9-56.7), and 3 patients achieved complete response (CR) (intention-to-treat analysis). The DCR was 90.0% (95% CI: 76.3-97.2) (intention-to-treat analysis). The median TTR was 1.5 (95% CI: 1.4-3.0) months. The median PFS was 8.2 (95% CI: 4.9 - not reached) months. 23 patients (50.0%) were still on treatment. Neither PD-L1 status (CPS score) nor lines of prior systemic therapies was correlated with ORR (P=0.782 and 0.651, respectively). All patients suffered from treatment-related adverse events (TRAEs) of any grade, while 34.8% of patients had experienced grade 3 or 4 TRAEs. Key grade 3 or 4 TRAEs were thrombocytopenia (13.0%), leukopenia (13.0%), and elevated aspartate aminotransferase (8.7%). No treatment-related deaths were observed. Conclusions: Camrelizumab in combination with apatinib and eribulin showed favorable efficacy and measurable toxicities in treating heavily pretreated patients with advanced TNBC. This trial is currently ongoing. ClinicalTrials.gov number, NCT04303741. Summary of clinical response in the intention-to-treat population.ParameterOverall (n=40)ORR, %16 (40.0; 24.9-56.7)DCR, %36 (90.0; 76.3-97.2)Median TTR, m1.5 (1.4-3.0)Median PFS, m8.2 (4.9-not reached)The data are presented in the form of n (%; 95% CI), or median time (95% CI). Citation Format: Jieqiong Liu, Zhenluan Tian, Ying Wang, Ying Lin, Hengyu Li. Preliminary safety and efficacy results of camrelizumab in combination with apatinib and eribulin in heavily pretreated patients with advanced triple-negative breast cancer: A phase II trial [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-14-08.