Dihydroorotate dehydrogenase (DHODH) is an enzyme ubiquitously expressed in all tissues whose inhibition has proven effective in preventing viral replication. Previous knowledge on DHODH inhibitor vidofludimus calcium demonstrated that this compound inhibits viral replication of DNA, RNA and retroviruses and induces innate immune responses that lead to an antiviral state thus inhibiting virus reactivation.

Shanghai Huilun Pharmaceutical Co. Ltd. has identified thiazle derivatives acting as dihydroorotate dehydrogenase (DHODH) inhibitors reported to be useful for the treatment of cancer, viral infections and autoimmune diseases.

Wigen Biomedicine Technology (Shanghai) Co. Ltd. has described 1,2,4-triazolone derivatives acting as dihydroorotate dehydrogenase (DHODH) inhibitors reported to be useful for the treatment of solid tumors and hematologic blood cancer.

Immunic AG has disclosed deuterated dihydroorotate dehydrogenase (DHODH) inhibitors 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.

DUBLIN – The most solid conclusion that can be drawn from Immunic Inc.’s phase II trial of IMU-838 in hospitalized COVID-19 patients is that a reduction in the need for invasive ventilation is no longer a useful endpoint for studies of COVID-19 drugs.