RESUMEN
Brain metastases are a leading cause of death in patients with breast cancer. The lack of clinical trials and the presence of the blood-brain barrier limit therapeutic options. Furthermore, overexpression of the human epidermal growth factor receptor 2 (HER2) increases the incidence of breast cancer brain metastases (BCBM). HER2-targeting agents, such as the monoclonal antibodies trastuzumab and pertuzumab, improved outcomes in patients with breast cancer and extracranial metastases. However, continued BCBM progression in breast cancer patients highlighted the need for novel and effective targeted therapies against intracranial metastases. In this study, we engineered the highly migratory and brain tumor tropic human neural stem cells (NSCs) LM008 to continuously secrete high amounts of functional, stable, full-length antibodies against HER2 (anti-HER2Ab) without compromising the stemness of LM008 cells. The secreted anti-HER2Ab impaired tumor cell proliferation in vitro in HER2+ BCBM cells by inhibiting the PI3K-Akt signaling pathway and resulted in a significant benefit when injected in intracranial xenograft models. In addition, dual HER2 blockade using anti-HER2Ab LM008 NSCs and the tyrosine kinase inhibitor tucatinib significantly improved the survival of mice in a clinically relevant model of multiple HER2+ BCBM. These findings provide compelling evidence for the use of HER2Ab-secreting LM008 NSCs in combination with tucatinib as a promising therapeutic regimen for patients with HER2+ BCBM.
Asunto(s)
Antineoplásicos Inmunológicos/metabolismo , Neoplasias Encefálicas , Neoplasias Experimentales , Células-Madre Neurales , Oxazoles/farmacología , Piridinas/farmacología , Quinazolinas/farmacología , Receptor ErbB-2 , Animales , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/terapia , Línea Celular Tumoral , Humanos , Ratones , Ratones Desnudos , Metástasis de la Neoplasia , Neoplasias Experimentales/genética , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Neoplasias Experimentales/terapia , Células-Madre Neurales/metabolismo , Células-Madre Neurales/patología , Células-Madre Neurales/trasplante , Receptor ErbB-2/antagonistas & inhibidores , Receptor ErbB-2/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Breast cancer brain metastases (BCBM) are the final frontier in neuro-oncology for which more efficacious therapies are required. In this work, we explore clinical trials in BCBM, and determine the shortcomings in the development of new BCBM therapies to shed light on potential areas for enhancement. METHODS: On July 9, 2018, we searched ClinicalTrials.gov for all interventional and therapeutic clinical trials involving BCBM, without limiting for date or location. Information on trial characteristics, including phase, status, start and end dates, study design, primary endpoints, selection criteria, sample size, experimental interventions, results, and publications were collected and analyzed. RESULTS: Fifty-three trials fulfilled the selection criteria. Median trial duration across phases ranged between 3 and 6 years. More than half of the trials were conducted in the United States. Although 94% of the trials were in early phases (I-II), 20% of patients were in phase III trials. Two phase III trials were anteceded by phase II trials that were non-randomized; one reported positive results. Approximately one-third of the trials were completed, whereas 23% of trials were terminated early; mostly due to inadequate enrollment. Only 13% of all trials and 22% of completed trials had published results directly linked to their primary outcomes. CONCLUSIONS: The low number of trials and accrual numbers, the lack of diversity, and the scarcity of published results represent the main troubles in clinical BCBM research. Optimization of BCBM trials is necessary to achieve effective therapies.