Immunic AG has identified deuterated dihydroorotate dehydrogenase (DHODH) inhibitors containing a carboxylic acid bioisostere. They are reported to be useful for the treatment of Crohn’s disease, influenza, lupus erythematosus, multiple sclerosis, psoriasis, rheumatoid arthritis, SARS-CoV-2 infection (COVID-19) and cancer, among others.