Definition

An antibody liposomal formulation containing the hydrochloride (HCl) salt form of the antineoplastic anthracycline antibiotic doxorubicin encapsulated within liposomes which contains TL01, a human epidermal growth factor receptor 2 (HER2)-directed trastuzumab Fab fragment conjugated lipid, with potential antineoplastic activity. Upon administration of HER2-targeted liposomal doxorubicin HCl HF158K1, the immunoliposome targets and binds to HER2-expressing tumor cells, thereby allowing for specific delivery of doxorubicin to tumors overexpressing the HER2 receptor. Once inside the HER2-expressing tumor cells, doxorubicin intercalates into DNA and interferes with topoisomerase II activity, thereby inhibiting DNA replication and RNA synthesis. Compared to doxorubicin alone or liposomal doxorubicin, targeted liposomal delivery of doxorubicin improves efficacy while lowering the toxicity profile. HER2, a tyrosine kinase receptor, is overexpressed in many cancer cell types.