Calliditas Therapeutics AB (publ) operates as a clinical-stage biopharmaceutical entity, committed to identifying, advancing, and commercializing therapeutic products. Its primary focus lies in developing treatments for rare (orphan) conditions, with a particular emphasis on disorders impacting the renal and hepatic systems. The company markets Nefecon, an orally administered formulation of budesonide, which functions as an immunosuppressive agent designed to address immunoglobulin A nephropathy, an autoimmune kidney disease.