Denosumab is a monoclonal antibody used for skeletal events in bone metastases and giant cell tumour of bone. Its target and the electrolyte abnormality it characteristically causes are:

• A RANK ligand; hypocalcaemia ✓
• B Osteoprotegerin; hypercalcaemia
• C Sclerostin; hypophosphataemia
• D Parathyroid hormone receptor; hypercalcaemia

Explanation

Denosumab is a fully human IgG2 antibody against RANK ligand, blocking osteoclast differentiation, function and survival. By suppressing osteoclastic bone resorption it can cause marked hypocalcaemia, especially in renal impairment and vitamin D deficiency, so calcium and vitamin D supplementation is advised. Osteoprotegerin is the endogenous decoy receptor for RANKL, not the drug target. Romosozumab, not denosumab, targets sclerostin, and teriparatide acts on the PTH receptor.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

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Written and medically reviewed by the StethoPrep medical team.