Quality Assessment of Pre-Clinical Studies of Chimeric Antigen Receptor T-Cell Therapy Products: A Point of Focus on Safety

Curr Drug Saf. 2022;17(2):129-135. doi: 10.2174/1574886316666210728101333.

Abstract

Background: Serious adverse reactions have been reported with the use of Chimeric Antigen Receptor (CAR) T-cell therapy in a clinical setting despite the success of these products in pre- clinical stages of development.

Objective: We evaluated the quality of available pre-clinical safety data of CAR T-cell therapy products.

Methods: A 21 items safety checklist was designed specifically for CAR T-cell. Literature was searched using search/MeSH terms in PubMed (October 2019 - February 2020). Studies were screened from title and abstract. Original pre-clinical researches related to CAR T-cell anti-cancer therapy were included.

Results: Of the search results, 152 studies (3 in vivo, 39 in vitro, and 110 combined) were included. Only 7.9% of studies were specifically designed to evaluate/ improve product safety. Eleven studies included target antigen(s), and no study included co-stimulatory molecule(s) expressed exclusively by the tumor tissue and/or CAR T-cells. One study used CRISPR-Cas9 for CAR gene insertion. The use of switch-off mechanism and purity assessment of CAR T-cell products were reported in 13.2% and 8.6% studies, respectively. Of the 113 studies with in vivo components, immuno- competent animal models were used in 24.8%. Measurements of blood pressure, temperature, body weight, and serum cytokines were reported in 0, 2.7, 29.2, and 27.4% studies, respectively. The tissue distribution and CAR T-cells persistence were reported in 26.5% of studies. The surface expression level of CAR, functional characterization of the product, and use of control were reported in >90% of studies.

Conclusion: The majority of the checklist parameters were not reported in the pre-clinical publications to be adequately predictive of the safety of CAR T-cells in a clinical setting.

Keywords: Adverse effects; CAR T-cell; anticancer; chimeric antigen receptor; quality of preclinical studies; safety.

MeSH terms

  • Animals
  • Cell- and Tissue-Based Therapy
  • Humans
  • Immunotherapy, Adoptive* / adverse effects
  • Immunotherapy, Adoptive* / methods
  • Receptors, Antigen, T-Cell / genetics
  • Receptors, Antigen, T-Cell / metabolism
  • Receptors, Chimeric Antigen* / genetics
  • Receptors, Chimeric Antigen* / metabolism
  • T-Lymphocytes / metabolism

Substances

  • Receptors, Antigen, T-Cell
  • Receptors, Chimeric Antigen