Background: Site-specific delivery of anti-cancer therapeutics is paramount for both reducing nonspecific toxicities and increasing efficacy of chemotherapeutic agents. Due to their small molecular size and nonspecific mechanisms of action, most conventional chemotherapies result in significant toxicities that limit the effectiveness of treatment and reduce the overall quality of life for cancer patients. Encapsulation of these toxic agents inside lipid-based carrier systems (so-called liposomes) results in passive targeting of the compounds to solid tumors. The preferential delivery of liposomal drugs to solid tumors is mostly due to altered barrier-properties of tumor-associated vessels. This results in both an improved delivery and at the same time a significantly milder toxicity profile. Recently, the specificity of delivery was further increased by attaching monoclonal antibodies or antibody fragments to the surface of liposomes (=immunoliposomes, antibody-linked nanoparticles). Antibody-coated immunoliposomes attach more selectively to antigens expressed on the target cells and they are internalized more efficiently. Furthermore, there is evidence that drug resistance, a major challenge in cancer treatment, may be overcome by such delivery systems. A logical and accessible target, such as EGFR, is overexpressed on a variety of primary human cancer cells and it is involved in signaling pathways that contribute both to tumor initiation and tumor progression. Recently, the investigators have tested immunoliposomes against the epidermal growth factor receptor (EGFR) in a preclinical setting. Based on the preclinical results we have initiated this phase I clinical trial.