Pharmacology General 7783479e Belimumab is used in A Osteoporosis B Malignant melanoma C Merkel cell carcinoma D Systemic lupus erythematous High-Yield Explanation Belimumab is a monoclonal antibody against B - cell activating factor ( BAFF ) and is thus useful in decreasing autoimmune response in Systemic lupus erythematous .