There are direct and indirect indications that PEGylated liposomal doxorubicin (Doxil), a widely used anticancer nanomedicine, has a subclinical immune suppressive effect. As an example of a seemingly bad pharmacological property turning out to be "not-so-ugly", but actually beneficial, the authors highlight the potential benefits of Doxil's immune suppressive effect. These include (1) the decreased uptake of the drug by the MPS which may entail enhanced tumor uptake, and, hence, improved therapeutic efficacy; (2) the use of slow infusion protocols in reducing the risk of hypersensitivity (infusion) reactions; and (3), possible protection against hypersensitivity reactions to co-administered reactogenic drugs. To consider immune suppression as useful represents a paradigm shifts in nanotoxicology and anticancer chemotherapy.
Keywords: Allergic reactions; anaphylaxis; complement; drug delivery; hypersensitivity; liposomes; phospholipids.