Abstract 87P
Background
There is a growing need for more advanced, composite biomarkers to evaluate the dynamic interplay between a tumor and the immune system that dictates the likelihood of response to precision cancer therapies. However, many of today’s CGP platforms, with their focus on mutational changes in a small panel of genes, provide limited data to support integrative, multidimensional biomarkers that can better predict immunotherapy response.
Methods
To enable the identification of such signatures, we have developed the Personalis® NeXT Platform™, an augmented exome/transcriptome-based platform that simultaneously profiles the tumor and immune microenvironment from a single FFPE sample.
Results
By co-optimizing assay and analytics design, we validated the sensitive assessment of SNVs, indels, CNAs, and fusions from as little as >=25ng of co-extracted DNA/RNA, while also verifying the analysis of neoantigens, HLA typing and LOH, antigen processing machinery (APM), TCR/BCR repertoire, immune expression signatures, tumor-infiltrating lymphocytes (TILs), oncoviruses, MSI, and TMB. Leveraging this expansive feature set, we developed methods that combine individual analytes to construct composite biomarker scores that correlate with immunotherapy response, including our proprietary NEOantigen Presentation Score (NEOPS).
Conclusions
Our cancer immunogenomics platform can be leveraged for the development of advanced composite biomarkers that combine both tumor and immune features from DNA and RNA; enabling more accurate stratification of patient response to immunotherapy. The platform has been validated and optimized for use with limited FFPE tissue samples, making it ideal for both clinical and research applications.
Legal entity responsible for the study
Personalis, Inc.
Funding
Personalis, Inc.
Disclosure
R. Power, G. Bartha, J. Harris, S.M. Boyle, E. Levy, P. Milani, P. Tandon, P. McNitt, M. Morra, S. Desai, S. Saldivar, M. Clark: Shareholder/Stockholder/Stock options, Full/Part-time employment: Personalis, Inc. C. Haudenschild: Leadership role, Shareholder/Stockholder/Stock options: Personalis, Inc. J. West: Leadership role, Shareholder/Stockholder/Stock options, Full/Part-time employment, Officer/Board of Directors: Personalis, Inc. R. Chen: Leadership role, Shareholder/Stockholder/Stock options, Full/Part-time employment: Personalis, Inc.