Avelumab (Anti-Human PD-L1, Human Antibody)

Cell experiment:

To examine the relationship between a cancer stem cell (CSC) subpopulation and antibody-dependent cell-mediated cytotoxicity (ADCC) activity, UM-Chor1 cells are left untreated or treated with 50 ng/mL of IFN-γ for 24 h. Cells are then plated as targets at 50,000 cells/well in 6-well round-bottom culture plates and incubated with 2 μg/mL of Avelumab at room temperature for 30 min. NK cells are added at 2500,000 cells/well at an effector-to-target (E:T) ratio of 50:1. After 4 h, tumor cells are harvested and stained with antibodies for flow cytometry[1].

Animal experiment:

Female C57BL/6 mice are used in this study. Subcutaneous tumor injections are carried out by inoculating C57BL/6 mice with 1×105 MB49 parental cells on the right shaved flank. Tumor growth is measured with calipers and 8 days post-inoculation mice are assigned to treatment groups. Tumor-bearing mice are treated with Avelumab (400 µg per 100 µL) and injected i.p. three times, 3 days apart. Since Avelumab is a human IgG1, three injections have to be compressed within a 7 to 9 day window (i.e., days 9, 12, and 15 post-tumor inoculation) to avoid the onset of neutralizing mouse anti-human Ig[3].

References:

[1]. Fujii R, et al. Enhanced killing of chordoma cells by antibody-dependent cell-mediated cytotoxicity employing the novel anti-PD-L1 antibody avelumab. Oncotarget. 2016 Jun 7;7(23):33498-511.
[2]. Grenga I, et al. A fully human IgG1 anti-PD-L1 MAb in an in vitro assay enhances antigen-specific T-cell responses. Clin Transl Immunology. 2016 May 20;5(5):e83.
[3]. Vandeveer AJ, et al. Systemic Immunotherapy of Non-Muscle Invasive Mouse Bladder Cancer with Avelumab, an Anti-PD-L1 Immune Checkpoint Inhibitor. Cancer Immunol Res. 2016 May;4(5):452-62.