Combination therapy with anti-CTLA-4 and anti-PD-1 leads to distinct immunologic changes in vivo

J Immunol. 2015 Feb 1;194(3):950-9. doi: 10.4049/jimmunol.1401686. Epub 2014 Dec 24.


Combination therapy concurrently targeting PD-1 and CTLA-4 immune checkpoints leads to remarkable antitumor effects. Although both PD-1 and CTLA-4 dampen the T cell activation, the in vivo effects of these drugs in humans remain to be clearly defined. To better understand biologic effects of therapy, we analyzed blood/tumor tissue from 45 patients undergoing single or combination immune checkpoint blockade. We show that blockade of CTLA-4, PD-1, or combination of the two leads to distinct genomic and functional signatures in vivo in purified human T cells and monocytes. Therapy-induced changes are more prominent in T cells than in monocytes and involve largely nonoverlapping changes in coding genes, including alternatively spliced transcripts and noncoding RNAs. Pathway analysis revealed that CTLA-4 blockade induces a proliferative signature predominantly in a subset of transitional memory T cells, whereas PD-1 blockade instead leads to changes in genes implicated in cytolysis and NK cell function. Combination blockade leads to nonoverlapping changes in gene expression, including proliferation-associated and chemokine genes. These therapies also have differential effects on plasma levels of CXCL10, soluble IL-2R, and IL-1α. Importantly, PD-1 receptor occupancy following anti-PD-1 therapy may be incomplete in the tumor T cells even in the setting of complete receptor occupancy in circulating T cells. These data demonstrate that, despite shared property of checkpoint blockade, Abs against PD-1, CTLA-4 alone, or in combination have distinct immunologic effects in vivo. Improved understanding of pharmacodynamic effects of these agents in patients will support rational development of immune-based combinations against cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / pharmacology
  • Antibodies, Monoclonal / therapeutic use
  • Antigens, Surface
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • CTLA-4 Antigen / antagonists & inhibitors*
  • Cytokines / blood
  • Gene Expression Profiling
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Immunophenotyping
  • Ipilimumab
  • Lymphocytes, Tumor-Infiltrating / immunology
  • Lymphocytes, Tumor-Infiltrating / metabolism
  • Neoplasms / drug therapy*
  • Neoplasms / genetics
  • Neoplasms / immunology*
  • Neoplasms / metabolism
  • Nivolumab
  • Programmed Cell Death 1 Receptor / antagonists & inhibitors*
  • Signal Transduction
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocyte Subsets / metabolism


  • Antibodies, Monoclonal
  • Antigens, Surface
  • CTLA-4 Antigen
  • Cytokines
  • Ipilimumab
  • Programmed Cell Death 1 Receptor
  • Nivolumab