Data and metadata supporting the article: PD-L1 immunohistochemistry for canine cancers and clinical benefit of anti-PD-L1 antibody in dogs with pulmonary metastatic oral malignant melanoma

In the present study, canine Programmed death-ligand 1 (PD-L1) expression was assessed in various cancer types, using a new anti-PD-L1 mAb, 6C11-3A11, and the safety and efficacy of c4G12 were explored in 29 dogs with pulmonary metastatic oral malignant melanoma (OMM).<br><b>Data access</b>: High resolution immunohistochemistry (IHC) and computerized tomography (CT) images supporting figures 1 and 2 of the article, are available in the figshare repository, as part of this data record. Baseline blood test analysis data supporting figure 3, are also part of this figshare data record. The datasets supporting the survival analysis plots in figure 3, and all other data supporting the findings of the current study, are included in the supplementary files that accompany the article. <br><b>Study approval and ethical compliance</b>: The study was approved by the Institutional Animal Care Committee, Hokkaido University (Approval number: 15-0149) and the Faculty of Veterinary Medicine, Hokkaido University (Approval number: 15028). The use of animals throughout the clinical study was approved by the ethics committee, Faculty of Veterinary Medicine, Hokkaido University. Prior to study enrollment, written informed consent was obtained from both the dogs’ owner and veterinarian.<br><b>Study aims and methodology</b>: Immunotherapy targeting programmed cell death 1 (PD-1) and PD-ligand 1 (PD-L1) represents promising treatments for human cancers.Recent studies have demonstrated that the PD-1/PD-L1 pathway is also involved in immune evasion of canine cancers. Some canine cancers, including OMM, were reported to express PD-L1, and specific anti-PD-1/PD-L1 mAbs induced immune-cell activation in vitro. However, few studies have attempted to assess PD-L1 expression in various canine cancers, and there is currently no consensus on PD-L1 expression status in each cancer type. The authors of this study aimed to assess PD-L1 expression in various cancer types, including OMM, using a novel anti-PD-L1 mAb (6C11-3A11) and compared its sensitivity to 6G7-E1, a previously reported mAb for canine IHC.In addition, a recent pilot study demonstrated antitumor efficacy of a canine chimeric anti-PD-L1 mAb (c4G12) against canine OMM and undifferentiated sarcoma (n = 2), among a sample of 9 dogs. The authors further aimed to assess the efficacy and safety of c4G12, in dogs with pulmonary metastatic OMM, using a predetermined dosage regimen. A secondary objective included the exploration of factors predictive of survival, including known correlates of improved survival in anti-PD-1/PD-L1 therapy-treated patients; use of radiation therapy, C reactive protein (CRP) level and lymphocyte-to-monocyte ratio (LMR).Formalin-fixed and paraffin-embedded (FFPE) tissue samples were used for PD-L1 IHC. A new anti-PD-L1 mAb, 6C11-3A11, was used for ICH.In total, 29 dogs were enrolled in the study. PD-L1 expression in the primary tumors, obtained by surgical excision at prior surgeries or biopsies, was assessed by 6C11-3A11 IHC. Dogs were treated with c4G12 every 2 weeks at 2 mg or 5 mg/kg by intravenous administration using a syringe pump over 1 hour. For more details on the methodology, including evaluation of adverse events, evaluation of tumour response and evaluation of survival, please refer to the related article.<br><b>Data supporting the findings of the study</b>: The following image files are in <b>.jpg file format</b> and show PD-L1 <b>immunohistochemistry data</b> with 6C11-3A11: Figure 1a.jpg, Figure 1b.jpg, Figure 1c.jpg, Figure 1d.jpg, Figure 1e.jpg and Figure 1f.jpg. These are the high-resolution images included in figure 1 of the article.<br>The following files are in .jpg file format and show <b>computed tomography (CT) scans</b> of dogs with oral malignant melanoma, that were receiving treatment with c4G12: Figure 2a.jpg, Figure 2b.jpg and Figure 2c.jpg.<br>The dataset <b>Baseline blood test.xlsx, </b>is in .xlsx file format, and includes the blood test analysis data of 29 dogs at baseline. The file includes data on the baseline levels of C-Reactive Protein, lymphocyte-to-monocyte ratio, absolute lymphocyte count, and absolute monocyte count.<br>Additional data supporting the findings of the current study, are included in the supplementary files that accompany the article. <br>