Immune checkpoint inhibitors have improved the survival of patients with various types of cancer. Despite the increasing indications and use in earlier stages, a portion of patients does not benefit from immune checkpoint inhibitors. Extensive research is being conducted to find predictive biomarkers to select patients who will benefit from immunotherapy. Current biomarkers such as PD-L1 expression, MSI, and TMB are not accurate enough. PET imaging can visualize biomarkers throughout the body, which can help optimize immunotherapy treatments.
A general introduction and outline of the thesis of Jahlisa Hooiveld-Noeken were provided, followed by an overview of biomarkers and ways to improve treatment strategies for patients with rare advanced skin cancers. The transition of immunotherapy from metastatic to neoadjuvant settings for skin cancer was discussed, driven by similar known response rates for non-melanoma skin cancer and melanoma. The use of [18F]FB-IL2 PET to visualize T-cell activity in patients with melanoma was evaluated, as well as the biodistribution and pharmacokinetics of pacmilimab, a probody targeting PD-L1. PET imaging with 89Zr-labeled PD-1 antibody pembrolizumab was used to predict response to immunotherapy, and the visualization of CD8+ T-cells as a potential biomarker for immunotherapy response was investigated. Repeated CD8+ PET imaging in patients with advanced melanoma was performed, and PD-L1 saturation by 89Zr-atezolizumab PET imaging during treatment was evaluated.
Immunotherapy has improved the survival of patients with advanced cancer. Future efforts focus on optimizing treatment timing, patient selection, and developing new combination therapies. PET imaging can aid in the development of new drugs and predicting anti-tumor responses.
