PT  - JOURNAL ARTICLE
AU  - Kotanides, Helen
AU  - Sattler, Rose Marie
AU  - Lebron, Maria B.
AU  - Carpenito, Carmine
AU  - Shen, Juqun
AU  - Li, Jingxing
AU  - Surguladze, David
AU  - Haidar, Jaafar N.
AU  - Burns, Colleen
AU  - Shen, Leyi
AU  - Inigo, Ivan
AU  - Pennello, Anthony L.
AU  - Forest, Amelie
AU  - Chen, Xinlei
AU  - Chin, Darin
AU  - Sonyi, Andreas
AU  - Topper, Michael
AU  - Boucher, Lauren
AU  - Sharma, Prachi
AU  - Zhang, Yiwei
AU  - Burtrum, Douglas
AU  - Novosiadly, Ruslan D.
AU  - Ludwig, Dale L.
AU  - Plowman, Gregory D.
AU  - Kalos, Michael
TI  - Characterization of 7A5: A Human CD137 (4-1BB) Receptor Binding Monoclonal Antibody with Differential Agonist Properties That Promotes Antitumor Immunity
AID  - 10.1158/1535-7163.MCT-19-0893
DP  - 2020 Apr 01
TA  - Molecular Cancer Therapeutics
PG  - 988--998
VI  - 19
IP  - 4
4099  - http://mct.aacrjournals.org/content/19/4/988.short
4100  - http://mct.aacrjournals.org/content/19/4/988.full
SO  - Mol Cancer Ther2020 Apr 01; 19
AB  - The CD137 receptor plays a key role in mediating immune response by promoting T cell proliferation, survival, and memory. Effective agonism of CD137 has the potential to reinvigorate potent antitumor immunity either alone or in combination with other immune-checkpoint therapies. In this study, we describe the discovery and characterization of a unique CD137 agonist, 7A5, a fully human IgG1 Fc effector-null monoclonal antibody. The biological properties of 7A5 were investigated through in vitro and in vivo studies. 7A5 binds CD137, and the binding epitope overlaps with the CD137L binding site based on structure. 7A5 engages CD137 receptor and activates NF-κB cell signaling independent of cross-linking or Fc effector function. In addition, T cell activation measured by cytokine IFNγ production is induced by 7A5 in peripheral blood mononuclear cell costimulation assay. Human tumor xenograft mouse models reconstituted with human immune cells were used to determine antitumor activity in vivo. Monotherapy with 7A5 inhibits tumor growth, and this activity is enhanced in combination with a PD-L1 antagonist antibody. Furthermore, the intratumoral immune gene expression signature in response to 7A5 is highly suggestive of enhanced T cell infiltration and activation. Taken together, these results demonstrate 7A5 is a differentiated CD137 agonist antibody with biological properties that warrant its further development as a cancer immunotherapy.Graphical Abstract: http://mct.aacrjournals.org/content/molcanther/19/4/988/F1.large.jpg.This article is featured in Highlights of This Issue, p. 973