Efficacy and safety of apatinib combined with nab-paclitaxel for second-line treatment of metastatic triple negative breast cancer (TNBC): An open-label phase II trial.

Abstract

e13127 Background: Apatinib is an oral, highly potent tyrosine-kinase inhibitor targeting VEGFR2. Preclinical studies have demonstrated that apatinib can enhance the anti-tumor effect of taxanes in TNBC via promoting apoptosis and suppressing migration and invasion of tumor cells. Previous studies have also shown the role of apatinib in combination with chemotherapy for treating TNBC. However, combinational treatment of apatinib and nab-paclitaxel for metastatic TNBC has not been reported. Therefore, the objective of this study was to evaluate the safety and efficacy of apatinib in combination with nab-paclitaxel as a second-line treatment for TNBC. Methods: This is a single-center, single-arm, and open-label prospective study. The patients enrolled in this study had metastatic TNBC, ECOG PS 0-2, at least one measurable lesion, and had previously received one systemic therapy except apatinib and nab-paclitaxel. They were treated with apatinib (250mg, PO, QD) plus nab-paclitaxel (125mg/m2, IV, day 1, 8 and 15) every 3 weeks as second-line treatment until disease progression, unacceptable toxicity, or consent withdrawal. The study utilized RECIST v1.1 to assess efficacy and NCI-CTCAE 5.0 to report adverse events. The study's primary endpoints were tolerability and progressive free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR) and disease control rate (DCR). Results: Twenty patients were enrolled by the cut-off date of December 1st, 2023. The median age was 55 years (range 31-76) and all had an ECOG PS of 0-1. Ninety percent of the sample had a Ki67 of 30% or higher, while 85% tested negative for PD-L1. All patients had distant metastases, with 35.0% having visceral metastasis and 35% having metastatic sites of 3 or more. 70% of patients had undergone surgery on the primary tumor. All patients received apatinib plus nab-paclitaxel treatment, with a median of 9 cycles (range 2-25), were included in the safety dataset. All patients experienced grade 1-2 treatment-related adverse events (TRAEs). Haematological toxicity of grade 3-4 with neutropenia occurred in 25.0% of patients. In addition, non-haematological toxicities were observed in 10% of patients, including abnormal hepatic function (5.0%) and hypertension (5.0%). No treatment-emergent adverse event (TEAE) resulted in death during the study. Out of the 20 evaluated patients, the median progression-free survival (PFS) was 6.7 months (95% CI: 6.0-NR). The objective response rate (ORR) was 65.0% (13/20), and the disease control rate (DCR) was 90.0% (18/20), according to RECIST v1.1. The median overall survival (OS) has not yet been reached. Conclusions: The combination of apatinib and nab-paclitaxel showed promising antitumor activity in patients with metastatic TNBC as a second-line treatment, with a manageable safety profile. Clinical trial information: NCT05019690 .