Phase 2 trial of adebrelimab with bevacizumab and cisplatin or carboplatin for triple-negative breast cancer with brain metastases

The phase 2 ABC study, at Fudan University (Shanghai, China) evaluated the triple combination therapy of adebrelimab, bevacizumab, and chemotherapy (cisplatin or carboplatin) for triple-negative breast cancer (TNBC) with brain metastases (BMs). A total of 35 patients (median 2 previous lines of therapy; range 0-4) received the combination until disease progression or unacceptable toxicity. The primary endpoint was objective response rate in CNS (CNS-ORR). The confirmed CNS-ORR was 77.1% (95% CI 59.9-89.6) with 5 complete reponses, whereas the CNS clinical benefit rate was 80.0% (63.1-91.6); the median overall progression-free survival (PFS) was 8.3 months (5.8-11.5) while the median CNS PFS was 10.3 months (7.4-14.3) and the median overall survival was 21.1 months (13.2-NR). Among the 28 patients who progressed, progression was intracranial-only in 32.1%, extranial-only in 35.7%, and both in 32.1%. The incidence of grade 3 or 4 treatment-related adverse events was 65.7%; no treatment-related deaths occurred. The authors conclude that the ABC combination demonstrated promising intracranial antitumor activity and prolonged PFS and CNS-PFS, with a manageable safety profile.