@article{LangZaitsevaWajant2022,
  author    = {Lang, Isabell and Zaitseva, Olena and Wajant, Harald},
  title     = {FcγRs and their relevance for the activity of anti-CD40 antibodies},
  series = {International Journal of Molecular Sciences},
  volume    = {23},
  journal   = {International Journal of Molecular Sciences},
  number    = {21},
  issn      = {1422-0067},
  doi       = {10.3390/ijms232112869},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-290458},
  year      = {2022},
  abstract  = {Simple Summary Targeting of CD40 with antibodies attracts significant translational interest. While inhibitory CD40 targeting appears particularly attractive in the field of organ transplantation and for the treatment of autoimmune diseases, stimulatory CD40 targeting is the aim in tumor immunotherapy and vaccination against infectious pathogens. It turned out that lack of FcγR-binding is the crucial factor for the development of safe and well-tolerated inhibitory anti-CD40 antibodies. In striking contrast, FcγR-binding is of great importance for the CD40 stimulatory capacity of the majority of anti-CD40 antibodies. Typically, anti-CD40 antibodies only robustly stimulate CD40 when presented by FcγRs. However, FcγR-binding of anti-CD40 antibodies also triggers unwanted activities such as destruction of CD40 expressing cells by ADCC or ADCP. Based on a brief discussion of the mechanisms of CD40 activation, we give an overview of the ongoing activities in the development of anti-CD40 antibodies under special consideration of attempts aimed at the development of anti-CD40 antibodies with FcγR-independent agonism or FcγR subtype selectivity. Abstract Inhibitory targeting of the CD40L-CD40 system is a promising therapeutic option in the field of organ transplantation and is also attractive in the treatment of autoimmune diseases. After early complex results with neutralizing CD40L antibodies, it turned out that lack of Fcγ receptor (FcγR)-binding is the crucial factor for the development of safe inhibitory antibodies targeting CD40L or CD40. Indeed, in recent years, blocking CD40 antibodies not interacting with FcγRs, has proven to be well tolerated in clinical studies and has shown initial clinical efficacy. Stimulation of CD40 is also of considerable therapeutic interest, especially in cancer immunotherapy. CD40 can be robustly activated by genetically engineered variants of soluble CD40L but also by anti-CD40 antibodies. However, the development of CD40L-based agonists is biotechnologically and pharmacokinetically challenging, and anti-CD40 antibodies typically display only strong agonism in complex with FcγRs or upon secondary crosslinking. The latter, however, typically results in poorly developable mixtures of molecule species of varying stoichiometry and FcγR-binding by anti-CD40 antibodies can elicit unwanted side effects such as antibody-dependent cellular cytotoxicity (ADCC) or antibody-dependent cellular phagocytosis (ADCP) of CD40 expressing immune cells. Here, we summarize and compare strategies to overcome the unwanted target cell-destroying activity of anti-CD40-FcγR complexes, especially the use of FcγR type-specific mutants and the FcγR-independent cell surface anchoring of bispecific anti-CD40 fusion proteins. Especially, we discuss the therapeutic potential of these strategies in view of the emerging evidence for the dose-limiting activities of systemic CD40 engagement.},
  language  = {en}
}
@article{BrunekreeftStrohmGoodenetal.2014,
  author    = {Brunekreeft, Kim L. and Strohm, Corinna and Gooden, Marloes J. and Rybczynska, Anna A. and Nijman, Hans W. and Grigoleit, G{\"o}tz U. and Helfrich, Wijnand and Bremer, Edwin and Siegmund, Daniela and Wajant, Harald and de Bruyn, Marco},
  title     = {Targeted delivery of CD40L promotes restricted activation of antigen-presenting cells and induction of cancer cell death},
  series = {Molecular Cancer},
  volume    = {13},
  journal   = {Molecular Cancer},
  number    = {85},
  issn      = {1476-4598},
  doi       = {10.1186/1476-4598-13-85},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-116682},
  year      = {2014},
  abstract  = {Background: Stimulation of CD40 can augment anti-cancer T cell immune responses by triggering effective activation and maturation of antigen-presenting cells (APCs). Although CD40 agonists have clinical activity in humans, the associated systemic activation of the immune system triggers dose-limiting side-effects. Methods: To increase the tumor selectivity of CD40 agonist-based therapies, we developed an approach in which soluble trimeric CD40L (sCD40L) is genetically fused to tumor targeting antibody fragments, yielding scFv: CD40L fusion proteins. We hypothesized that scFv: CD40L fusion proteins would have reduced CD40 agonist activity similar to sCD40L but will be converted to a highly agonistic membrane CD40L-like form of CD40L upon anchoring to cell surface exposed antigen via the scFv domain. Results: Targeted delivery of CD40L to the carcinoma marker EpCAM on carcinoma cells induced dose-dependent paracrine maturation of DCs similar to 20-fold more effective than a non-targeted control scFv: CD40L fusion protein. Similarly, targeted delivery of CD40L to the B cell leukemia marker CD20 induced effective paracrine maturation of DCs. Of note, the CD20-selective delivery of CD40L also triggered loss of cell viability in certain B cell leukemic cell lines as a result of CD20-induced apoptosis. Conclusions: Targeted delivery of CD40L to cancer cells is a promising strategy that may help to trigger cancer-localized activation of CD40 and can be modified to exert additional anti-cancer activity via the targeting domain.},
  language  = {en}
}