作者：Tanaya Vaidya¹, Robert M. Straubinger², Sihem Ait-Oudhia¹ 

    ¹.Center for Pharmacometrics and Systems Pharmacology, Department of Pharmaceutics, College of Pharmacy University of Florida, Orlando, USA

    ².Department of Pharmaceutical Sciences University at Buffalo, State University of New York, Buffalo, USA

摘要：

Purpose

Trastuzumab combined with Doxorubicin (DOX) demonstrates significant clinical activity in human epidermal growth factor receptor-2 (HER2)-positive breast cancer (BC). However, emergence of treatment resistance and trastuzumab associated cardiotoxicity remain clinical challenges. In an effort to improve patient outcome, we have developed and evaluated novel tri-functional immunoliposomes (TFIL) that target HER2-receptors on BC cells and CD3-receptors on T-lymphocytes, and deliver DOX.

Methods

Trastuzumab (anti-HER2) and OKT-3 (anti-CD3) antibodies were conjugated to liposomes using a micelle-transfer method. Cytotoxicity of targeted immunoliposomes loaded with DOX was examined in vitro on HER2-positive BC cells (BT474), with peripheral blood monocytic cells (PBMC) as immune effector cells.

Results

TFIL demonstrated high antibody-liposome conjugation ratios (100–130 μg protein/μmol phospholipid) and cargo capacity (0.21 mol:mol drug:lipid), highly efficient DOX loading (>90%), a particle size favorable for extended circulation (~150 nm), and good stability (up to 3 months at 4°C). In the presence of PBMCs, TFIL showed complete killing of BT474 cells, and were superior to mono-targeted trastuzumab-bearing liposomes, non-targeted liposomes, and free Trastuzumab and DOX.

Conclusions

Novel anti-HER2xCD3 + DOX TFIL show promise as a means to both engage immune cells against HER2 positive breast cancer cells and deliver chemotherapy, and have the potential to improve clinical outcomes.