Anti-EGFR antibody-drug conjugate carrying an inhibitor targeting CDK restricts triple-negative breast cancer growth.
Clin Cancer Res 2024:745404. [PMID:
38772416 DOI:
10.1158/1078-0432.ccr-23-3110]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 03/06/2024] [Accepted: 05/15/2024] [Indexed: 05/23/2024]
Abstract
PURPOSE
Anti-EGFR antibodies show limited response in breast cancer, partly due to activation of compensatory pathways. Furthermore, despite clinical success of CDK4/6 inhibitors in hormone receptor-positive tumors, aggressive triple-negative breast cancers (TNBCs) are largely resistant due to CDK2/cyclin E expression, while free CDK2 inhibitors display normal tissue toxicity, limiting their therapeutic application. A cetuximab-based antibody drug conjugate (ADC) carrying a CDK inhibitor selected based on oncogene dysregulation, alongside patient subgroup stratification, may provide EGFR-targeted delivery.
EXPERIMENTAL DESIGN
Expression of G1/S-phase cell cycle regulators were evaluated alongside EGFR in breast cancer. We conjugated cetuximab with CDK inhibitor SNS-032, for specific delivery to EGFR-expressing cells. We assessed ADC internalization, and its anti-tumor functions in vitro and in orthotopically-grown basal-like/TNBC xenografts.
RESULTS
Transcriptomic (6173 primary, 27 baseline and matched post-chemotherapy residual tumors), scRNA-seq (150290 cells, 27 treatment-naïve tumors) and spatial transcriptomic (43 tumor sections, 22 TNBCs) analyses confirmed expression of CDK2 and its cyclin partners in basal-like/TNBCs, associated with EGFR. Spatiotemporal live-cell imaging and super-resolution confocal microscopy demonstrated ADC colocalization with late lysosomal clusters. The ADC inhibited cell cycle progression, induced cytotoxicity against high EGFR-expressing tumor cells and bystander killing of neighboring EGFR-low tumor cells, but minimal effects on immune cells. Despite carrying a small fraction of the drug, the ADC restricted EGFR-expressing spheroid and cell line/patient-derived xenograft tumor growth.
CONCLUSIONS
Exploiting EGFR overexpression, and dysregulated cell cycle in aggressive and treatment-refractory tumors, a cetuximab-CDK inhibitor ADC may provide selective and efficacious delivery of cell cycle-targeted agents to basal-like/TNBCs, including chemotherapy-resistant residual disease.
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