Antibody-based Cancer Immunotherapy : Personalization, response prediction and safety considerations

Abstract: Antibody-based therapeutics have remarkably improved the field of immuno-oncology. Multiple monoclonal antibodies (mAbs) are approved for clinical use, and numerous antibodies are under clinical development. The scope of this thesis is to study the personalization of antibody-based immunotherapeutics and tools to predict their efficacy and safety.In paper I, we investigated a new method for predicting immune toxicity related to mAbs infusion, the whole blood loop assay (WBLA). The assay recapitulates the in vivo setting and harmonizes well with clinically validated cytokine release assays (CRAs) following agonistic mAbs infusion. We also demonstrated the robustness of the assay in studying complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC).Rituximab, the first approved mAb for an oncology indication, is known to induce CRS occasionally. In paper II, the WBLA was used to profile the chronic lymphocytic leukemia (CLL) patients’ specific responses to rituximab infusion. We demonstrated rituximab-induced CRS profile and complement activation in blood from CLL patients but not in blood from healthy donors. We also noted that NK cells were a significant source of the rituximab-induced cytokine release. Using Fc mutant versions of rituximab, the mode-of-action of rituximab in whole blood with respect to CDC and ADCC was elaborated.In paper III, we presented a novel flexible peptide cancer vaccine platform based on an anti-CD40 agonistic antibody. The platform consists of a bispecific antibody targeting CD40 and peptide-tagged antigens. The bispecific antibody retained the agonistic activity of anti-CD40 and was superior to parental anti-CD40 mAb in targeting antigen cross-presentation and stimulating both CD8+ and CD4+ T cell responses.In paper IV, we investigated the feasibility of proximity-extension assay (PEA) plasma proteomic analysis in predicting response to checkpoint inhibitors (CPIs) in non-small cell lung cancer patients. CPIs show great success in the clinic. However, not all patients benefit from CPIs. Using an immuno-oncology protein panel, we demonstrated that high plasma levels of T cell activation proteins were associated with better survival. We also identified an association between the pre-CPI plasma levels of CXCL9, CXCL10, IL-15, ADA and Casp8 and the response to CPI therapy. In conclusion, this thesis demonstrates the feasibility of using the WBLA to assess antibody infusion efficacy and safety, as well as PEA plasma proteomics to predict response to CPI therapy. Additionally, it presents a novel approach for personalized therapeutic cancer vaccine delivery.