BrAin Metastasis in tripLe Negateive Breast Cancer: IvoneScimab and Trop2 ADC

Brain metastasis is a common site of metastasis in triple-negative breast cancer (TNBC), with an incidence rate of approximately 30-45%. Once breast cancer patients develop brain metastasis, their survival period is short and prognosis is poor. The median overall survival (mOS) of TNBC patients with brain metastasis is even less than 6 months. Therefore, it is necessary and urgent to explore effective treatment regimens to improve the survival of patients with breast cancer brain metastasis. In recent years, several novel drugs, including immunotherapy, anti-angiogenic targeted therapy, and antibody-drug conjugates (ADCs), have achieved significant success in metastatic TNBC, significantly improving the prognosis and survival of advanced TNBC. The combination of immune checkpoint inhibitors and anti-angiogenic therapy has also become an important treatment strategy for TNBC. The results of a phase Ib/II study of PM8002 (a bispecific antibody targeting PD-L1 and VEGF-A, exerting both immune and anti-angiogenic effects) combined with albumin-bound paclitaxel in the treatment of advanced TNBC patients showed that the objective response rate (ORR) was 78.6%, and the median progression-free survival (mPFS) was 14 months. AK112, a bispecific antibody targeting PD-1 and VEGF-A, combined with chemotherapy, was approved by the National Medical Products Administration（NMPA） of Cnina on May 10, 2024, for the treatment of patients with advanced non-squamous NSCLC with EGFR mutations who have progressed after EGFR-TKI treatment. Notably, the efficacy analysis of NSCLC patients with baseline brain metastasis in the 201/202 studies of AK112 showed that the intracranial response rate of AK112 combined with platinum-based chemotherapy was 39% (including 25% complete response); the intracranial response rate of AK112 monotherapy also reached 14%. For untreated brain metastasis patients, the intracranial mPFS of the AK112-containing regimen was as long as 19.3 months. At the 2024 ESMO conference, a study on the safety and efficacy of AK112 combined with paclitaxel or albumin-bound paclitaxel as first-line treatment for advanced TNBC was reported. The study results showed that the overall ORR was 78.8%, the 6-month PFS rate was 73.3%, and the mPFS and OS have not yet been reached. These results suggest that AK112 may also have great application potential in TNBC patients with brain metastasis. In addition, sacituzumab govitecan is a novel ADC targeting TROP2. Based on the results of the large-scale phase III ASCENT study, it has been approved for the treatment of second-line and later-line metastatic TNBC. Through subgroup analysis of brain metastasis patients in the ASCENT study, we found that the PFS of brain metastasis patients in the SG group was significantly better than that of the control chemotherapy group (2.8 months vs. 1.6 months), indicating that ADCs targeting the TROP2 also have good efficacy in TNBC brain metastasis. Therefore, a prospective, single-arm, phase II clinical study of AK112 combined with TROP2 ADC in the treatment of triple-negative breast cancer brain metastasis is planned, aiming to explore the efficacy and safety of AK112 combined with TROP2 ADC in the treatment of TNBC brain metastasis patients.