In a broader sense, one can also count sodium metaarsenite (NaAsO2) among the immune modulators, because it dampens the production of certain messenger substances of the immune system (the cytokines), which can trigger intensive immune reactions. The South Korean company Komipharm has thus developed a medicine against tumour-associated pain (project name PAX-1-001). It has now applied for clinical trials to test the medicine in Covid-19 patients.

https://www.vfa.de/de/arzneimittel-forschung/woran-wir-forschen/therapeutic-medicines-coronavirus-covid-19