An anti-PD-1-GITR-L bispecific agonist induces GITR clustering-mediated T cell activation for cancer immunotherapy

Nat Cancer. 2022 Mar;3(3):337-354. doi: 10.1038/s43018-022-00334-9. Epub 2022 Mar 7.


Costimulatory receptors such as glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR) play key roles in regulating the effector functions of T cells. In human clinical trials, however, GITR agonist antibodies have shown limited therapeutic effect, which may be due to suboptimal receptor clustering-mediated signaling. To overcome this potential limitation, a rational protein engineering approach is needed to optimize GITR agonist-based immunotherapies. Here we show a bispecific molecule consisting of an anti-PD-1 antibody fused with a multimeric GITR ligand (GITR-L) that induces PD-1-dependent and FcγR-independent GITR clustering, resulting in enhanced activation, proliferation and memory differentiation of primed antigen-specific GITR+PD-1+ T cells. The anti-PD-1-GITR-L bispecific is a PD-1-directed GITR-L construct that demonstrated dose-dependent, immunologically driven tumor growth inhibition in syngeneic, genetically engineered and xenograft humanized mouse tumor models, with a dose-dependent correlation between target saturation and Ki67 and TIGIT upregulation on memory T cells. Anti-PD-1-GITR-L thus represents a bispecific approach to directing GITR agonism for cancer immunotherapy.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cluster Analysis
  • Disease Models, Animal
  • Glucocorticoid-Induced TNFR-Related Protein / agonists
  • Humans
  • Immunotherapy / methods
  • Mice
  • Neoplasms* / drug therapy
  • Programmed Cell Death 1 Receptor*
  • Receptors, Tumor Necrosis Factor / agonists
  • T-Lymphocytes


  • Glucocorticoid-Induced TNFR-Related Protein
  • Programmed Cell Death 1 Receptor
  • Receptors, Tumor Necrosis Factor