Immunotherapy for Glioblastoma: Current Progress and Challenges

Front Immunol. 2021 May 13:12:676301. doi: 10.3389/fimmu.2021.676301. eCollection 2021.

Abstract

Glioblastoma is a highly lethal brain cancer with a median survival rate of less than 15 months when treated with the current standard of care, which consists of surgery, radiotherapy and chemotherapy. With the recent success of immunotherapy in other aggressive cancers such as advanced melanoma and advanced non-small cell lung cancer, glioblastoma has been brought to the forefront of immunotherapy research. Resistance to therapy has been a major challenge across a multitude of experimental candidates and no immunotherapies have been approved for glioblastoma to-date. Intra- and inter-tumoral heterogeneity, an inherently immunosuppressive environment and tumor plasticity remain barriers to be overcome. Moreover, the unique tissue-specific interactions between the central nervous system and the peripheral immune system present an additional challenge for immune-based therapies. Nevertheless, there is sufficient evidence that these challenges may be overcome, and immunotherapy continues to be actively pursued in glioblastoma. Herein, we review the primary ongoing immunotherapy candidates for glioblastoma with a focus on immune checkpoint inhibitors, myeloid-targeted therapies, vaccines and chimeric antigen receptor (CAR) immunotherapies. We further provide insight on mechanisms of resistance and how our understanding of these mechanisms may pave the way for more effective immunotherapeutics against glioblastoma.

Keywords: brain cancer; glioblastoma; immunotherapy; resistance to therapy; tumor microenvironment.

Publication types

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

MeSH terms

  • Animals
  • Brain Neoplasms / immunology*
  • Brain Neoplasms / therapy*
  • Cancer Vaccines / therapeutic use*
  • Disease Models, Animal
  • Glioblastoma / immunology*
  • Glioblastoma / therapy*
  • Humans
  • Immune Checkpoint Inhibitors / therapeutic use*
  • Immunotherapy, Adoptive / methods*
  • Mice
  • Molecular Targeted Therapy / methods*
  • Treatment Outcome
  • Tumor Microenvironment / immunology
  • Tumor-Associated Macrophages / drug effects*
  • Tumor-Associated Macrophages / immunology
  • Vaccination / methods*

Substances

  • Cancer Vaccines
  • Immune Checkpoint Inhibitors