A groundbreaking phase 0 study has revealed promising results for Sacituzumab govitecan (Trodelvy) in treating both breast cancer brain metastases (BCBM) and recurrent glioblastoma multiforme (rGBM), potentially offering new hope for patients with limited treatment options.
Significant Brain Tumor Penetration Demonstrated
The single-center, non-randomized trial conducted at the University of Texas Health Science Center at San Antonio evaluated 25 patients who received a single 10 mg/kg intravenous dose of Sacituzumab govitecan one day before tumor resection. The study demonstrated substantial intracranial penetration, with median total SN-38 concentrations reaching 249.8 ng/g in BCBM and 104.5 ng/g in rGBM patients.
Promising Survival Outcomes
The trial revealed encouraging survival metrics across both patient groups. The BCBM cohort achieved an overall survival of 35.2 months, while the rGBM cohort reached 9.5 months. Progression-free survival was observed at 8 months for BCBM patients and 12 months for rGBM patients. The objective response rates were notably positive, with 38% in BCBM and 29% in rGBM patients.
Target Expression and Safety Profile
Analysis of Trop-2 expression, the target of Sacituzumab govitecan, showed presence in 100% of BCBM and 78% of rGBM tumors, supporting the drug's mechanism of action. The safety profile proved favorable, with manageable adverse events. The most significant grade 3 or higher side effects included neutropenia (28%), hypokalemia (8%), and several other conditions occurring at 8% frequency.
Clinical Context and Significance
The findings are particularly significant given that 15-25% of stage 4 breast cancer patients develop brain tumors, with current treatment options often proving ineffective. Dr. Andrew J. Brenner, professor and chair of neuro-oncology research at UT Health San Antonio's Mays Cancer Center, emphasized the trial's importance: "Our trial revealed that it could achieve concentrations of inhibitors inside the tumors sufficient to benefit patients, and with minimal side effects, which is very promising for new therapy."
Novel Treatment Approach
As an antibody-drug conjugate targeting Trop-2, Sacituzumab govitecan represents a novel approach to overcoming the blood-brain barrier, one of the primary challenges in treating brain malignancies. The study suggests that this targeted delivery method could provide a new therapeutic strategy for patients with brain tumors, who traditionally face limited treatment options and poor prognoses.
