A potential role for cyclophosphamide in the mitigation of acute respiratory distress syndrome among patients with SARS-CoV-2

Med Hypotheses. 2020 Nov;144:109850. doi: 10.1016/j.mehy.2020.109850. Epub 2020 May 23.


While humanity struggles to develop a vaccine against SARS-CoV-2, it is imperative that effective and affordable therapeutic strategies be evolved. Since a majority of the SARS-CoV-2 deaths are due to acute respiratory distress syndrome (ARDS), a strategy to mitigate the same could save countless lives. Since SARS-CoV-2 related ARDS has a strong immunological component, many investigators are utilizing monoclonal antibodies against IL-6, TNF-alpha and CCR5. However, targeting a single cytokine with an expensive monoclonal antibody could be a less pragmatic approach. We propose the use of cyclophosphamide as an immunomodulator, given its proven role in various settings including autoimmune diseases, and in the post-haploidentical stem cell transplant. Cyclophosphamide could deplete cytotoxic and effector T cell populations while relatively sparing the regulatory T cells (Tregs). Cyclophosphamide could tip the balance away from the overtly pro-inflammatory and could be a less expensive and effective alternative to the currently investigated monoclonal antibodies.

Keywords: ARDS; COVID; Cyclophosphamide; SARS-CoV-2; Treg.

MeSH terms

  • Antibodies, Monoclonal / therapeutic use
  • COVID-19 / complications
  • COVID-19 Drug Treatment*
  • Cyclophosphamide / therapeutic use*
  • Humans
  • Immune System / drug effects
  • Patient Safety
  • Respiratory Distress Syndrome / drug therapy*
  • Respiratory Distress Syndrome / virology
  • T-Lymphocytes, Regulatory / cytology
  • T-Lymphocytes, Regulatory / drug effects


  • Antibodies, Monoclonal
  • Cyclophosphamide