Expert opinions on endocrine toxicity induced by new anticancer therapies: Precautions to be taken in performing and interpreting hormonal assays under immunotherapy.

ABSTRACT

As well as tyrosine kinase and mTOR inhibitors, new anticancer therapies make use of antibodies targeting tyrosine kinase receptors or blocking anti-tumor immune response checkpoints. These are always monoclonal; in their international non-proprietary names, the origin is prefixed to "-mab" e.g., mouse antibodies end in "o-mab", chimeric antibodies in "xi-mab", humanized antibodies in "zu-mab" and human antibodies in "u-mab". When the analytic principle of the assay involves a murine monoclonal antibody and the therapeutic antibody contains a murine sequence, analytic interference is to be feared if the patient develops antibodies against the therapeutic antibody. The interfering heterophilic antibody may be a HAMA (anti-mouse), a HACA (anti-chimeric) or a HAHA (anti-humanized-antibody). In immunoassay for patients under immunotherapy, it is therefore recommended to check the type of therapeutic antibody if it is liable to contain murine sequences, heterophilic antibodies should be screened for and neutralized.