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Purpose: In a recent phase II study of onartuzumab (MetMAb), patients whose non–small cell lung cancer (NSCLC) tissue scored as positive for MET protein by immunohistochemistry (IHC) experienced a significant benefit with onartuzumab plus erlotinib (O+E) versus erlotinib. We describe development and validation of a standardized MET IHC assay and, retrospectively, evaluate multiple biomarkers as predictors of patient benefit.Experimental Design: Biomarkers related to MET and/or EGF receptor (EGFR) signaling were measured by IHC, FISH, quantitative reverse transcription PCR, mutation detection techniques, and ELISA.Results: A positive correlation between IHC, Western blotting, and MET mRNA expression was observed in NSCLC cell lines/tissues. An IHC scoring system of MET expression taking proportional and intensity-based thresholds into consideration was applied in an analysis of the phase II study and resulted in the best differentiation of outcomes. Further analyses revealed a nonsignificant overall survival (OS) improvement with O+E in patients with high MET copy number (mean ≥5 copies/cell by FISH); however, benefit was maintained in “MET IHC-positive”/MET FISH-negative patients (HR, 0.37; P = 0.01). MET, EGFR, amphiregulin, epiregulin, or HGF mRNA expression did not predict a significant benefit with onartuzumab; a nonsignificant OS improvement was observed in patients with high tumor MET mRNA levels (HR, 0.59; P = 0.23). Patients with low baseline plasma hepatocyte growth factor (HGF) exhibited an HR for OS of 0.519 (P = 0.09) in favor of onartuzumab treatment.Conclusions: MET IHC remains the most robust predictor of OS and progression-free survival benefit from O+E relative to all examined exploratory markers. Clin Cancer Res; 20(17); 4488–98. ©2014 AACR.

Additional methodology describing cell lines and tissues, as well as detailed methodology for gene expression, flow cytometry, IHC and FISH studies.

Figure S1. Characterization of SP44 specificity; Figure S2. Relationship of IHC intensity with FACS; Figure S3. Relationship of IHC intensity with mRNA; Figure S4. Representative IHC images; Figure S5 and S6. MET IHC H-scores; Figure S7. Relationship of IHC clinical score with MET copy number; Figure S8. Kaplan-Meier curves of OS according to MET copy number; Figure S9. Relationship of plasma HGF with MET Dx positivity.

Table S1. Overlap of biomarkers measured in OAM4558g; Table S2. Primer/probe information; Table S3. MET diagnostic scoring criteria; Table S4. MET IHC intratumoral heterogeneity; Table S5. Impact of KRAS/EGFR mutation on clinical outcome; Table S6. Biomarker status in EGFR-mutant patients; Table S7. Association of transcript expression with PFS in OAM4558g.

Purpose: In a recent phase II study of onartuzumab (MetMAb), patients whose non–small cell lung cancer (NSCLC) tissue scored as positive for MET protein by immunohistochemistry (IHC) experienced a significant benefit with onartuzumab plus erlotinib (O+E) versus erlotinib. We describe development and validation of a standardized MET IHC assay and, retrospectively, evaluate multiple biomarkers as predictors of patient benefit. Experimental Design: Biomarkers related to MET and/or EGF receptor (EGFR) signaling were measured by IHC, FISH, quantitative reverse transcription PCR, mutation detection techniques, and ELISA. Results: A positive correlation between IHC, Western blotting, and MET mRNA expression was observed in NSCLC cell lines/tissues. An IHC scoring system of MET expression taking proportional and intensity-based thresholds into consideration was applied in an analysis of the phase II study and resulted in the best differentiation of outcomes. Further analyses revealed a nonsignificant overall survival (OS) improvement with O+E in patients with high MET copy number (mean ≥5 copies/cell by FISH); however, benefit was maintained in “MET IHC-positive”/MET FISH-negative patients (HR, 0.37; P = 0.01). MET, EGFR, amphiregulin, epiregulin, or HGF mRNA expression did not predict a significant benefit with onartuzumab; a nonsignificant OS improvement was observed in patients with high tumor MET mRNA levels (HR, 0.59; P = 0.23). Patients with low baseline plasma hepatocyte growth factor (HGF) exhibited an HR for OS of 0.519 (P = 0.09) in favor of onartuzumab treatment. Conclusions: MET IHC remains the most robust predictor of OS and progression-free survival benefit from O+E relative to all examined exploratory markers. Clin Cancer Res; 20(17); 4488–98. ©2014 AACR.

Dysregulation of the immune checkpoints has been identified as one of the mechanisms tumor cells employ for immune escape. Human papillomavirus (HPV) plays an important role in the etiology of one subset of Head and Neck Squamous Cell Carcinomas (HNSCC). Recent studies reported that PD-1/PD-L1 pathway may be correlated with HPV-associated HNSCC. The degree of PD-L1 expression has been reported to be increased in those patients with HPV-positive disease. Also, PD-L1 expression in HNSCC was observed in the primary, recurrent, and metastatic disease setting. However, the clinicopathological implications associated with PD-L1 in HNSCC, as well as in disease metastasis, remain largely unclear. Using immunohistochemistry (IHC) and In situ hybridization (ISH) on VENTANA BenchMark ULTRA automated stainers, 40 cases of HNSCC, with matching primary and metastatic cancer stages, were evaluated for expression of PD-L1, p16, a surrogate marker of transforming HPV infections, and presence of HPV. Formalin-fixed paraffin-embedded tumor samples were subjected to PD-L1- and p16-IHC as well as HPV-ISH. A potential association between PD-L1 expression and HPV status among primary tumors and matched metastases was analyzed. Our data show that expression of PD-L1 or p16 is concordant in the majority of HNSCC primary vs metastatic tumor cases tested. Agreement rate of p16 expression among 40 case pairs of primary vs metastatic tumor was 88.2% with a 95% Confidence Interval (CI) of (73.4-95.3). PD-L1 expression was 76.9% (61.7-87.4) concordant among the 40 case pairs. Agreement rate between PD-L1 and p16 was 77.1% (61.0-87.9) in primary cases and 51.3% (35.9-66.6) in metastatic cases. No obvious association between PD-L1 and p16 expression was observed. Citation Format: Chenglu C. Quon, Xiaoling Xia, Lupe Manriquez, Crystal Schemp, Dawn Sloane, Shahad Alabagi, Mohammed G. Abdelwahab, Pengfei Gu, Lizhen Pang, Khalid Hanif, Nicole Schechter. Correlation of PD-L1 expression and HPV status among primary and metastasized HNSCC tumors. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 477.

LGR5 (GPR49) is a Wnt pathway downstream target gene. It has already been confirmed that LGR5 gene is up regulated by APC or β-catenin mutation. LGR5 has recently been identified as a biomarker on the human and murine intestinal or colon stem cells. Our gene expression data shows that LGR5 is highly expressed in colon cancer, with minimal expression in normal tissue. Our strategy in this project is to eliminate tumor stem cells by drug conjugated antibody. Our goal is to find a tumor stem cell marker and develop antibody to target the tumor stem cells. Here we developed and characterized both anti-LGR5 phage and monoclonal antibodies by multi molecular techniques. We finally focus on one phage antibody (YW353) and three monoclonal antibodies (2H6, 3G12 and 8E11) as therapeutic drugs for further study. We evaluated antibody drug conjugate (ADC) in vitro and in vivo with different animal tumor models derived from cell lines and human tumor explants. Good efficacy was observed in these animal models following a single dose of 5mg/kg. Conclusion: LGR5 is an attractive colon cancer target for the administration of anti-LGR5 ADC in human cancer. More in vivo models will be tested to confirm the efficacy and evaluate safety. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4289.