Sacituzumab govitecan: breakthrough targeted therapy for triple-negative breast cancer

Introduction: Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype associated with an increased risk of recurrence and cancer-related death. Unlike hormone receptor-positive or HER2-positive breast cancers, there are limited targeted therapies available to treat TNBC and cytotoxic chemotherapy remains the mainstay of treatment. Sacituzumab govitecan (IMMU-132) is an antibody-drug conjugate targeting Trop-2 expressing cells and selectively delivering SN-38, an active metabolite of irinotecan.

Areas covered: This review covers the mechanism of action, safety and efficacy of sacituzumab govitecan in patients with previously treated, metastatic TNBC. Additionally, efficacy data in other epithelial malignancies is included based on a PubMed search for ‘sacituzumab govitecan’ and ‘clinical trial’.

Expert opinion: Sacituzumab govitecan has promising anti-cancer activity in patients with metastatic TNBC previously treated with at least two prior lines of systemic therapy based on a single arm Phase I/II clinical trial. A confirmatory Phase III randomized clinical trial is ongoing. Sacituzumab govitecan has a manageable side effect profile, with the most common adverse events being nausea, neutropenia, and diarrhea. The activity of sacituzumab govitecan likely extends beyond TNBC with promising early efficacy data in many other epithelial cancers, including hormone receptor-positive breast cancer.     

A distinctive cardiovascular lesion resembling histiocytoid (epithelioid) hemangioma. Evidence suggesting mesothelial participation

This paper presents 14 examples of a distinctive cardiovascular lesion. The patients' ages ranged from 5 to 76 years (mean, 51 years). There were seven male patients and seven female patients. All of the lesions were small and represented incidental surgical findings. Ten were attached to the endocardium, three were free-floating in the pericardial cavity, and one was inside a dissecting aneurysm of the ascending aorta. Microscopically, the lesions were enclosed in a fibrinous network and composed of a solid proliferation of round to polygonal cells with centrally located nuclei. Immunohistochemically, the cells were negative for FVIII-related antigen and lysozyme, but they stained positively for keratin, especially when clustered in small micropapillary or tubule-like formations. The nature and pathogenesis of these lesions are uncertain. Their location and some of their microscopic features originally suggested a relationship with the entity described as histiocytoid (epithelioid) hemangioma. However, their intense immunoreactivity for keratin, occasional presentation in the pericardial sac, and marked morphologic similarities with nodular mesothelial hyperplasia as sometimes seen in hernia sacs point toward the alternative possibility of a reactive mesothelial nature. A possible pathogenetic mechanism for the endocardial cases is ingrowth of pericardial mesothelial cells along a perforation tract that may have developed at the time of a cardiac catheterization. There were no recurrences or metastases in any of the cases.     

BookReviews

Annals of Vascular Surgery -