CAR T-cell Therapy

Chimeric antigen receptor T-cell therapy:

This provides a brief overview of CAR T-cell therapy. Major complications of CAR T-cell therapy including CRS and ICANS are covered under ?sec-haeme_cris and Immune-Effector Cell-Associated Neurotoxicity Syndrome, respectively.

Indications

Specific malignancies:

  • Aggressive, refractory, or relapsed B-cell lymphoma
  • Mantle cell lymphoma
  • Multiple myeloma

Contraindications

Principles

Therapy involves:

  • Apheresis of patients peripheral blood mononuclear cells
  • Cryopreservation and transfer to a manufacturing facility
  • Genetic modification of these cells to target a certain malignancy
    • Modification occurs with addition of the Chimeric Antigen Receptor gene to the cells, generally via a viral vector
    • Activation and clonal expansion of cells
  • Cryopreservation and transfer back to treating institution
    Entire process takes ~6 weeks.
  • Pre-treatment with lymphocyte-depleting chemotherapy
    Improves subsequent T-cell expansion.
  • Re-transfusion of the modified cells
    Generally via a central line to avoid extravasation.
  • Clonal expansion of administered cells

Genetic modifications are targeted at a particular receptor expressed by that cell. Consequently, all cells bearing this antigen will be targeted, which will include some non-malignant cells. This is known as ‘on-target, off-tumour’ toxicity.

Practice

Complications

Complications are common and may range from mild to life-threatening. They can be divided by time-course into:

CRS and ICANS are covered under ?sec-haeme_cris and Immune-Effector Cell-Associated Neurotoxicity Syndrome, respectively.

  • Acute toxicity
    Occurs 0-30 days after therapy:
    • Cytokine Release Syndrome
      Severe CRS also ↑ infective risk.
    • Immune Effector Cell-Associated Neurotoxicity Syndrome
    • Infection
      • Febrile neutropenia
    • Anaphylaxis
    • Coagulopathy
    • Thromboembolism
    • Tumour Lysis Syndrome
      Rare but remains a risk.
  • Delayed toxicity
    • Hypogammaglobulinaemia
    • Cytopaenias

Hypogammaglobulinaemia occurs due to destruction of B-cells relating to the CD-19 targeting CAR T-cells, which results in B-cell aplasia.

Key Studies


References

  1. Messmer AS, Que YA, Schankin C, Banz Y, Bacher U, Novak U, et al. CAR T-cell therapy and critical care. Wien Klin Wochenschr. 2021 Dec 1;133(23):1318–25.