Probes for INS

In this study, we present the clinicopathological features associated with PD-L1 protein and mRNA expression in a large Asian cohort of patients with non-small cell lung cancer (NSCLC) and assessed the prognostic implications of PD-L1 expression, particularly in early stage NSCLC. We retrospectively analyzed 687 NSCLC specimens (476 adenocarcinoma and 211 squamous cell carcinoma) using tissue microarray. PD-L1 immunohistochemistry (IHC) was performed using Dako 22C3 pharmDx assay and PDL1 mRNA was measured using RNA in situ hybridization (RISH). The overall prevalence of PD-L1 protein expression was 25.2% in tumor cells and PDL1 mRNA expression was 11.9%. There was a strong positive correlation between PD-L1 IHC and RISH results (Spearman's rho = 0.6, p<0.001). In adenocarcinoma, PD-L1 protein and mRNA expressions significantly correlated with poorly differentiated histologic subtype (p<0.001 and p = 0.002, respectively). PD-L1 expression was also associated with genetic alteration in adenocarcinoma. High PD-L1 expression level was associated with EGFR-naïve and KRAS-mutant subgroup (p = 0.001 and p = 0.017, respectively). With a 1% cut-off value, PD-L1 protein expression showed a short overall survival duration in early stage adenocarcinoma with marginal significance (p = 0.05, Hazard ratio = 1.947). Our study revealed that PD-L1 expression varied with histologic subtype and genomic alteration status in lung adenocarcinoma, and activation of the PD-L1 pathway may be a poor prognostic factor especially in early stage lung adenocarcinoma. In addition, PDL1 RISH showed promising results in predicting PD-L1 protein expression in NSCLC.

Primary mediastinal large B-cell lymphoma (PMLBCL) is recognized as a distinct clinicopathological entity in the current World Health Organization classification of lymphoid neoplasms (Swerdlow et al, 2016). Gene expression profiling studies have confirmed a distinct signature in PMLBCL that differs from diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS) and partially overlaps with that found in classical Hodgkin lymphoma (Savage et al, 2003; Bea et al, 2005). In routine clinical practice, however, distinguishing between PMLBCL and DLBCL, NOS is frequently difficult, due partly to a paucity of sensitive and specific biomarkers (Martelli et al, 2008; Dorfman et al, 2012). Recent studies have shown that PMLBCL shows frequent copy number alterations or translocations involving the CD274 (PD-L1) or PDCD1LG2 (PD-L2) genes at chromosome 9p24.1, leading to overexpression of CD274 (PD-L1) and, especially, PDCD1LG (PD-L2) proteins (Shi et al, 2014; Twa & Steidl, 2015). Anti-PDCD1LG2 antibodies suitable for immunohistochemical analysis in formalin-fixed paraffin-embedded (FFPE) tissue are not currently commercially available, limiting the utility of this potential marker for routine diagnostic practice. In this study, we have performed RNA in situ hybridization (RISH) for CD274 and PDCD1LG2 RNA expression, using a standard automated immunohistochemistry (IHC) platform, and have compared the results to IHC using a commercially available anti-CD274 antibody.

Human papillomavirus (HPV) infection is associated with several genetic alterations including oncogene amplification, leading to increased aggression of tumors. Recently, a relationship between HPV infection and oncogene amplification has been reported, but this finding remains controversial. This study therefore investigated relationships between HPV infection and amplification of genes in the epidermal growth factor receptor (EGFR) signaling cascade in oral squamous cell carcinoma (OSCC). Extracted DNA from 142 formalin-fixed paraffin-embedded (FFPE) OSCC tissues was performed to investigate the copy number of EGFR, KRAS, c-myc and cyclin D1 genes using real-time polymerase chain reaction (RT-PCR) and compared with calibrators. A tissue microarray of OSCC tissues was used for detection of c-Myc expression and HPV infection by immunohistochemistry and HPV E6/E7 RNA in situ hybridization, respectively. HPV infection was also investigated using PCR and RT-PCR. Of the 142 OSCC samples, 81 (57%) were HPV-infected cases. The most frequently amplified gene was c-myc (55.6%), followed by cyclin D1 (26.1%), EGFR (23.9%) and KRAS (19.7%). Amplification of c-myc was significantly associated with levels of its protein product. EGFR amplification was also significantly associated with amplification of genes in the signaling cascade: KRAS (50.0%), c-myc (34.2%) and cyclin D1 (46.0%). Interestingly, HPV infection was significantly associated with amplification of both EGFR (76.5%) and cyclin D1 (73.0%). Only cyclin D1 amplification was significantly associated with severity of OSCC histopathology. HPV infection may play an important synergistic role in amplification of genes in the EGFR signaling cascade, leading to increased aggression in oral malignancies.

Four immunohistochemistry (IHC) diagnostic assays have been approved for tumour PD-L1 protein assessment in the clinic. However, mRNA detection by in situ hybridisation (ISH) could be utilised as an alternative to protein detection. Detecting spatial changes in gene expression provides vital prognostic and diagnostic information, particularly in immune oncology where the phenotype, cellular infiltration and immune activity status may be associated with patient survival. Translation of mRNA expression to a clinically relevant cut off or threshold is challenging due to variability between assays and the detection of different analytes. These studies aim to confirm the suitability of formalin fixed paraffin embedded (FFPE) tissue sections for use with RNA ISH. A comparison of mRNA expression and protein expression may inform the suitability of mRNA as a patient selection biomarker in a similar manner to IHC and provide evidence of a suitable scoring algorithm. Ninety patient samples, thirty for each indication of non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC) and urothelial carcinoma (UC), previously assessed using the VENTANA PD-L1 (SP263) Assay were chosen to represent a wide dynamic range of percentage tumour cell staining (TCIHC). Expression of mRNA was assessed by ISH using the RNAScope 2.5 assay and probe CD274/PD-L1 (Advanced Cell Diagnostics) including kit provided positive and negative control probes. Brightfield whole slide images of tissues were captured. The percentage of tumour cells with PD-L1 mRNA expression (%TCmRNA) and mean punctate dots/tumour cell were determined using image analysis. Differences in RNA expression between the IHC derived TCIHC≥25% and <25% groups were assessed using t-tests. For each indication, a receiver-operating characteristic (ROC) analysis identified thresholds for patient classification using %TCmRNA and dots/tumour cell, with reference to TCIHC≥25%. Eighty-six samples were successfully tested; 3 failed due to insufficient control probe staining, 1 due to lack of tumour. Percent TCmRNA staining using RNAScope demonstrated statistical significance (at α = 0.05) in the PD-L1 high (TCIHC ≥25%) vs the PD-L1 low (TCIHC <25%) groups for NSCLC, HNSCC, and UC. The number of punctate dots/tumour cell was significantly higher in the PD-L1 high vs the PD-L1 low groups for NSCLC and HNSCC but not UC. For %TCmRNA; ROC analysis identified thresholds of: NSCLC 18.0%, HNSCC 31.8%, UC 25.8%. For dots/tumour cell, thresholds were: NSCLC 0.26, HNSCC 0.53, UC 0.45. Routine tissue fixation and processing is suitable for RNA detection using RNAScope. PD-L1 mRNA extent and level is associated with PD-L1 status determined by IHC. Threshold optimisation for %TCmRNA and mean dots/tumour cell results in high specificity to IHC PD-L1 classification, but only moderate sensitivity.

We have previously demonstrated that transcriptionally active high-risk HPV (hr-HPV) is strongly incriminated in Barrett's dysplasia (BD) and oesophageal adenocarcinoma (OAC) using mainly fresh frozen tissue. This study aimed to identify biomarkers of active HPV infection in Barrett's metaplasia, (BM)/BD/OAC by immunohistochemical staining (IHC) of formalin-fixed paraffin embedded (FFPE) tissue for aberrations of p53 and the retinoblastoma (pRb) pathway which are targets for the viral oncoproteins, E6/E7 respectively. Prospectively, BM(n=81)/BD(n=72)/OAC(n=65) FFPE specimens were subjected to IHC staining for pRb, p16INK4A , cyclin D1 , p53 and RNA in-situ hybridization (ISH) for E6/E7 transcripts. HPV DNA was determined via PCR in fresh frozen specimens. Viral load measurement (real-time PCR) and Next Generation Sequencing of TP53 was also performed. Of 218 patients, 56 were HPV DNA positive [HPV16 (n=42), 18 (n=13), 6 (n=1)]. Viral load was low. Transcriptionally active HPV (DNA+ /RNA+ ) was only found in the dysplastic and adenocarcinoma group (n=21). The majority of HPV DNA+ /RNA+ BD/OAC were characterized by p16INK4Ahigh (14/21, 66.7%), pRblow (15/21, 71.4%) and p53low (20/21, 95%) and was significantly different to controls [combination of HPV DNA- /RNA- (n=94) and HPV DNA+ /RNA- cohorts (n=22)]. p53low had the strongest association with DNA+ /RNA+ oesophageal lesions (OR=23.5, 95% CI=2.94-187.8, p=0.0029). Seventeen HPV DNA+ /RNA+BD/OAC identified as p53low, were sequenced and all but one exhibited wild-type status. pRblow /p53low provided the best balance of strength of association (OR=8.0, 95% CI=2.6-25.0, p=0.0003) and sensitivity (71.4%)/specificity (71.6%) for DNA+ /RNA+ BD/OAC. Active HPV involvement in BD/OAC is characterized by wild-type p53 and aberrations of the retinoblastoma protein pathway.

Abstract

PURPOSE:

Clinical responses with programmed death (PD-1) receptor directed antibodies occur in about 20% of patients with advanced head and neck squamous cell cancer (HNSCCa). Viral neoantigens, such as the E6/E7 proteins of HPV16/18 are attractive targets for therapeutic immunization, and offer an immune activation strategy that may be complementary to PD-1 inhibition.

EXPERIMENTAL DESIGN:

We report Phase Ib/II safety, tolerability and immunogenicity results of immunotherapy with MEDI0457 (DNA immunotherapy targeting HPV16/18 E6/E7 with IL-12 encoding plasmids) delivered by electroporation with CELLECTRA^® constant current device. Twenty-two patients with locally advanced, p16+ HNSCCa received MEDI0457.

RESULTS:

MEDI0457 was associated with mild injection site reactions but no treatment related grade 3-5 adverse events (AEs). Eighteen of 21 evaluable patients showed elevated antigen specific T cell activity by IFNg ELISpot and persistent cellular responses surpassing 100 SFU/106 PBMC were noted out to one year. Induction of HPV-specific CD8+ T cells was observed. MEDI0457 shifted the CD8+/FoxP3+ ratio in 4/5 post-immunotherapy tumor samples and increased the number of perforin+ immune infiltrates in all five patients. One patient developed metastatic disease and was treated with anti-PD-1 therapy with a rapid and durable complete response. Flow cytometric analyses revealed induction of HPV16 specific PD-1+ CD8+ T cells that were not found prior to MEDI0547 (0% vs. 1.8%).

CONCLUSIONS:

These data demonstrate that MEDI0457 can generate durable HPV16/18 antigen-specific peripheral and tumor immune responses. This approach may be used as a complementary strategy to PD-1/PD-L1 inhibition in HPV-associated HNSCCa to improve therapeutic outcomes.