SITC Clinical Immuno-Oncology Network (SCION) commentary on measurement and interpretation of essential biomarkers in early clinical trials

Immunotherapy of cancer is now a mainstay of modern oncologic practise and is being integrated with conventional modalities across clinical settings. The Society for Immunotherapy of Cancer (SITC) has initiated a Clinical Immuno-Oncology Network (SCION), where multidisciplinary teams (including clinical oncologists, scientists/immunologists, biostatisticians, and patient advocates) and early career scholars develop immunotherapy clinical trial protocols during an intensive workshop and Winter School. SCION participants have identified a critical gap in guidance for the prioritization of biomarkers in immunotherapy clinical trials. This commentary proposes an evidence-based consensus review process to generate a prioritized checklist of biomarkers for consideration. We recommend grouping biomarkers into three priority levels based on the strength of evidence, breadth of relevance, and feasibility of testing. Level one biomarkers should have strong evidence to justify inclusion in all immunotherapy trials. Level two biomarkers need early evidence supporting inclusion, dependent on suitable funding and scientific validity. Level three biomarkers are of specific importance for individual trials (eg, evaluating therapeutic targets). We invite feedback from the community on the proposed process and prioritization framework. The SCION faculty will work with the SITC Biomarker and Pathology Committees to publish recommendations emerging from a forthcoming evidence-based consensus review. Leveraging the annual clinical trial workshop, SCION faculty will evaluate emerging data to update recommendations as the field evolves.