Wyeth discovered and initially developed the drug, and clinical development continued after that company was acquired by Pfizer. Fezakinumab, in combination with methotrexate, completed a phase II trial in rheumatoid arthritis,[3] but data were not released. A small phase II trial of fezakinumab showed significant improvement in the Scoring Atopic Dermatitis (SCORAD) score for patients with severe atopic dermatitis.[4]