Generation of a canine anti-canine CD20 antibody for canine lymphoma treatment.

Takuya Mizuno
Yukinari Kato
Mika K Kaneko
Yusuke Sakai
Toshinori Shiga
Masahiro Kato
Toshihiro Tsukui
Hirofumi Takemoto
Akio Tokimasa
Kenji Baba
Yuki Nemoto
Osamu Sakai
Masaya Igase

Lymphoma is the most common hematological cancer in dogs. Canine diffuse large B cell lymphoma shows a relatively good response to treatment with multi-agent cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy; however, the 2-year survival rate is as low as 20%. For human B cell type lymphoma, the anti-CD20 chimeric antibody, rituximab, was developed two decades ago. The combination of rituximab and CHOP chemotherapy was highly successful in improving patient prognosis. However, no anti-canine CD20 antibody is available for the treatment of canine lymphoma. During this study, a rat anti-canine CD20 monoclonal antibody was established. We also generated a rat-canine chimeric antibody against canine CD20 designed for clinical application. This chimeric antibody (4E1-7-B) showed in vitro antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against the canine B cell lymphoma cell line CLBL-1. Moreover, to obtain stronger ADCC activity, a defucosylated 4E1-7-B antibody (4E1-7-B_f) was also generated, and it showed tenfold stronger ADCC activity compared with 4E1-7-B. 4E1-7-B_f as well as 4E1-7-B suppressed the growth of CLBL-1 tumors in an immunodeficient xenotransplant mouse model. Finally, a single administration of 4E1-7-B_f induced considerable peripheral B cell depletion in healthy beagles. Thus, 4E1-7-B_f is a good antibody drug candidate for canine B cell type lymphoma.

Scientific reports

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11476

10.1038/s41598-020-68470-9

https://doi.org/10.1038/s41598-020-68470-9
https://www.ncbi.nlm.nih.gov/pubmed/32651429
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7351721