Asociación entre el ARNm de PD1 y la respuesta a tratamiento con anti-PD1 en monoterapia en múltiples tipos de cánceres Tomás Pascual*, Laia Paré*, Elia Seguí*, Adela Rodríguez, Oscar Reig, Joan Maurel, Javier García-Corbacho, Cristina Teixidó, Ana Arance y Aleix Prat

Disclosure Information Employment: Consultant or Advisory Role: AP: Pfizer, Lilly, Novartis, Roche, Nanostring Technologies, Oncolytics Biotech Stock Ownership: Research Funding: AP: Novartis, Roche, Nanostring Technologies Speaking: Grant support: Other:

Background Anti-PD1 antibody drugs such as nivolumab or pembrolizumab have demonstrated unprecedented clinical efficacy in more than 15 cancer types. The overall response rate (ORR) achieved by these drugs across 22 cancer-types varies and ranges from 0% to 50% Patients responding to these therapies usually gain a large survival benefit from these drugs, leading to impressive outcomes Thus, selecting patients most likely to respond to anti-PD1 monotherapy is necessary

Non progressive disease Background Recent studies support the role of PD-L1 expression by immunohistochemistry (IHC) as a potential biomarker in NSCLC We previously reported that the expression of immune-related genes, including PD1, is associated with anti-PD1 monotherapy efficacy in 65 patients with advanced solid tumors Progression disease Non progressive disease Prat, Navarro et al. Cancer Research. 2017

Hypothesis We hypothesized that PD1 mRNA in tumor samples: Explain the ORR differences observed across different cancer-types following anti-PD1 monotherapy Provides superior predictive information with respect to other biomarkers

Methods Cohort#1 (from TCGA): Cohort#2 (in-house) RNAseq data from 10,462 samples representing 36 cancer-types. 18 immune-related gene signatures and 547 immune-related genes, including PD1, and TMB were explored. Correlations between each gene/signature and ORRs reported in the literature were calculated. Cohort#2 (in-house) FFPE-based PD1 mRNA data from 773 samples representing 17 cancer-types using the nCounter platform. Cohort#3 (in-house and GEM) FFPE-based PD1 mRNA data from an independent dataset of 117 patients with advanced solid tumors treated with anti-PD1 monotherapy (nivolumab or pembrolizumab).

PD1 and immune-related gene expression in TCGA PD1 highly correlated with a group of 30 genes, including CD3 and CD8A, which were found significantly enriched in biological processes such as CD8 T-cell activation. TCGA DATASET 36 tumor types 10,462 tumor samples 15,557 genes (RNAseq) Tumor Mutational Burden Acute Myeloid Leukemia Diffuse Large B-cell Lymphoma 151 Breast Cancer w/o subtype 12 Esophageal Carcinoma  w/o subtype Expression of PD1 mRNA across 34 cancer-types in TCGA. 15,010 non-immune genes 34 tumor types 10,078 tumor samples 547 immune genes (RNAseq) 18 immune GES (Including TIS and 2 clusters) Tumor Mutational Burden

Immune-related gene expression and reported anti-PD1 efficacys Immune Gene and GES Proportion Cutoff (Percentile). 90th PD1 0.86 CD8A IL12RB1 0.84 CCL5 0.83 80th PD1 0.91 KLRK1 0.85 Cytotoxic cell CD(A 70th LTA 0.82 PD1 0.81 KLRK1 0.78 Cytotoxic cell 60th PD1 0.82 LTA 0.77 CD8A 0.75 ICAM1 Mean ICAM 0.78 LTA 0.77 PD1 0.76 CTSW 0.71 PUBMED PHASE I-III TRIALS ANTI-PD1 MONOTHERAPY 16 cancer-types Correlation between the % of PD1-high and the reported ORR Overall Response Rate Proportion GES/Gene high 16 cancer-types TCGA 566 Genes/GES mRNA

Implementing PD1 expression in the clinical setting Expression of PD1 mRNA across 17 cancer-types in 773 FFPE samples. 773 In-house Dataset PD1 mRNA FFPE Nanostring Platform 17 cancer-types Proportion PD1-high Correlation of 80th Top Percentile PD1 mRNA expressers in TCGA vs in−house Proportion PD1-high 17 cancer-types TCGA PD1 mRNA

Direct association between PD1 expression and anti-PD1 efficacy 155 patients with advanced cancer treated with anti-PD1 monotherapy 117 FFPE tumor tissues obtained before anti-PD1 treatment Nanostring Patform

Conclusions PD1 expression correlates with high CD8 T-cell activation Cancer-types known to be anti-PD1 sensitive have higher PD1 expression than cancer-types known to be more anti-PD1 resistant The proportion of PD1-high tumors within each cancer-type ranges from 0 to 84% These proportions of PD1-high disease are strongly associated with the anti-PD1 sensitivity reported in the literature across cancer-types PD1 mRNA can be clinically implemented in FFPE tumor tissue and is found directly associated with anti-PD1 sensitivity regardless of the type of cancer

Acknowledgements We thank all the patients and family members for participating in the study BECA 40 ANIVERSARIO FSEOM – PARA PROYECTOS DE INVESTIGACIÓN EN INMUNO-ONCOLOGÍA