Immune-related adverse events of antibody-based biological medicines in cancer therapy.

Recombinant antibodies (Abs) are an integral modality for the treatment of multiple tumour malignancies. Since the Food and Drug Administration (FDA) approval of rituximab as the first monoclonal antibody (mAb) for cancer treatment, several mAbs and antibody (Ab)-based therapies have been approved for the treatment of solid tumour malignancies and other cancers. These Abs function by either blocking oncogenic pathways or angiogenesis, modulating immune response, or by delivering a conjugated drug. The use of Ab-based therapy in cancer patients who could benefit from the treatment, however, is still limited by associated toxicity profiles which may stem from biological features and processes related to target binding, alongside biochemical and/or biophysical characteristics of the therapeutic Ab. A significant immune-related adverse event (irAE) associated with Ab-based therapies is cytokine release syndrome (CRS), characterized by the development of fever, rash and even marked, life-threatening hypotension, and acute inflammation with secondary to systemic uncontrolled increase in a range of pro-inflammatory cytokines. Here, we review irAEs associated with specific classes of approved, Ab-based novel cancer immunotherapeutics, namely immune checkpoint (IC)-targeting Abs, bispecific Abs (BsAbs) and Ab-drug-conjugates (ADCs), highlighting the significance of harmonization in preclinical assay development for safety assessment of Ab-based biotherapeutics as an approach to support and refine clinical translation.

Using Reference Reagents to Confirm Robustness of Cytokine Release Assays for the Prediction of Monoclonal Antibody Safety.

New immunostimulatory antibody drugs designed to either directly stimulate specific immune cells or indirectly enhance the immune response by blocking or activating an endogenous regulator of the immune system have the potential to cause serious immune-related adverse events such as cytokine release syndrome (CRS). It is, therefore crucial to assess the safety profile of such drugs with a combination of in vivo and in vitro experiments before first-in-human dose administration. Cytokine release assays (CRAs), where the proposed antibody therapeutic is co-cultured with human immune cells (such as peripheral blood mononuclear cells (PBMCs), whole blood, or otherwise) and the amount of inflammatory cytokine produced is measured, are critical for hazard identification. However, different labs using different control antibodies can threaten the harmonization of CRAs, and clinically relevant controls (such as TGN1412) can be difficult to source, which can lead to less accurate or reliable results or data which are difficult to compare between laboratories. The inclusion of positive and negative controls in a CRA can ensure the accuracy and reliability of the results. The National Institute for Biological Standards and Control (NIBSC) has produced a panel of lyophilized antibody controls intended for use in various CRA platforms to harmonize results across various laboratories and assay methods. A set of three different positive control antibodies include anti-CD52, anti-CD3, and anti-CD28 superagonist (SA), which are known to induce dose-dependent CRS in patients. Each antibody is provided with an isotype-matched negative control antibody. This panel of reference reagents has previously been shown to have good inter-lab reproducibility and are suitable controls to increase the confidence and robustness of safety data from a variety of CRA platforms.