Denosumab is a RANK ligand (RANKL) inhibitor used for the following conditions:

Postmenopausal Osteoporosis (High Fracture Risk):
Denosumab is used to treat postmenopausal women with osteoporosis who have a high risk of fractures. This includes those with a prior osteoporotic fracture, multiple fracture risk factors, or those who cannot tolerate or did not respond to other osteoporosis treatments. It helps reduce the risk of vertebral, non-vertebral, and hip fractures.

Osteoporosis in Men:
It is used to increase bone mass in men with osteoporosis who are at high risk of fractures, including those with previous fractures, multiple risk factors, or intolerance/failure of other therapies.

Glucocorticoid-Induced Osteoporosis:
Denosumab is indicated for men and women at high fracture risk who are taking long-term glucocorticoid therapy (≥7.5 mg prednisone daily for at least 6 months). High risk includes prior fractures, multiple risk factors, or failure/intolerance to other treatments.

Bone Loss in Men Receiving Androgen Deprivation Therapy (Prostate Cancer):
Used to increase bone mass in men with nonmetastatic prostate cancer undergoing androgen deprivation therapy. It also lowers the risk of vertebral fractures.

Bone Loss in Women Receiving Aromatase Inhibitor Therapy (Breast Cancer):
Used to increase bone mass in women at high risk of fractures receiving adjuvant aromatase inhibitor therapy for breast cancer.

 Multiple Myeloma and Bone Metastases from Solid Tumors:
Denosumab is used to prevent skeletal-related events in patients with multiple myeloma or bone metastases from solid tumors.

Giant Cell Tumor of Bone:
Indicated for adults and skeletally mature adolescents with unresectable tumors or when surgery may cause severe complications.

Hypercalcemia of Malignancy:
Used to treat high calcium levels in cancer patients who do not respond to bisphosphonate therapy.

Denosumab is a fully human IgG2 monoclonal antibody that specifically targets RANK ligand (RANKL). It binds to RANKL, a protein found in both membrane-bound and soluble forms, which is essential for the development, activity, and survival of osteoclasts—the cells responsible for bone breakdown (resorption). By attaching to RANKL, Denosumab blocks its interaction with the RANK receptor located on osteoclasts and their precursor cells. This inhibition of the RANKL–RANK pathway reduces the formation, function, and survival of osteoclasts. As a result, bone resorption decreases, while bone mass and bone strength increase in both cortical and trabecular bone.

Denosumab should be administered by a healthcare professional. Denosumab is intended for subcutaneous route only and should not be administered intravenously, intramuscularly, or intradermally.

Treatment of Osteoporosis and Bone Loss: Administer 60 mg every 6 months as a subcutaneous injection in the upper arm, upper thigh, or abdomen. Instruct patients to take calcium 1000 mg daily and at least 400 IU vitamin D daily. If a dose of Denosumab is missed, administer the injection as soon as the patient is available. Thereafter, schedule injections every 6 months from the date of the last injection.

Multiple Myeloma and Bone Metastasis from Solid Tumors: Administer 120 mg every 4 weeks as a subcutaneous injection in the upper arm, upper thigh, or abdomen

Giant Cell Tumor of Bone: Administer 120 mg every 4 weeks with additional 120 mg doses on Days 8 and 15 of the first month of therapy. Administer subcutaneously in the upper arm, upper thigh, or abdomen. Administer calcium and vitamin D as necessary to treat or prevent hypocalcemia.

Hypercalcemia of Malignancy: Administer 120 mg every 4 weeks with additional 120 mg doses on Days 8 and 15 of the first month of therapy. Administer subcutaneously in the upper arm, upper thigh, or abdomen.

In patients with postmenopausal osteoporosis, Denosumab (60 mg given as a subcutaneous injection) does not influence the pharmacokinetics of midazolam, a drug metabolized by the cytochrome P450 3A4 (CYP3A4) enzyme. This suggests that Denosumab is unlikely to affect the pharmacokinetics of other medications that are processed by the same enzyme in this group of patients.

Hypocalcemia: Any existing hypocalcemia must be corrected before starting treatment with Denosumab.

Pregnancy: Denosumab may harm the fetus if given during pregnancy. Women of childbearing potential should undergo pregnancy testing before initiating therapy.

Hypersensitivity: Denosumab is contraindicated in patients with known systemic hypersensitivity to any of its components. Such reactions may include anaphylaxis, facial swelling, and urticaria (hives).

Postmenopausal Osteoporosis: The most common adverse reactions (>5%) include back pain, pain in the limbs, high cholesterol levels, musculoskeletal pain, and cystitis. Cases of pancreatitis have also been reported in clinical trials.

Osteoporosis in Men: The most frequently reported adverse effects (>5%) are back pain, joint pain (arthralgia), and nasopharyngitis.

Glucocorticoid-Induced Osteoporosis: Common adverse reactions (>3%) include back pain, high blood pressure, bronchitis, and headache.

Bone Loss Due to Hormone Ablation for Cancer: The most common adverse reactions (>10%) are joint pain and back pain. Limb pain and musculoskeletal pain have also been observed in clinical studies.

Bone Metastases from Solid Tumors: The most common adverse effects (>25%) include fatigue or weakness, low phosphate levels (hypophosphatemia), and nausea.

Multiple Myeloma: Common adverse reactions (>10%) include diarrhea, nausea, anemia, back pain, low platelet count (thrombocytopenia), peripheral edema, low calcium levels (hypocalcemia), upper respiratory tract infection, rash, and headache.

Giant Cell Tumor of Bone: The most frequently reported adverse effects (>10%) are joint pain, headache, nausea, back pain, fatigue, and limb pain.

Hypercalcemia of Malignancy: Common adverse reactions (>20%) include nausea, difficulty breathing (dyspnea), decreased appetite, headache, peripheral edema, vomiting, anemia, constipation, and diarrhea.

Pregnant Women and Females of Reproductive Potential: Denosumab may cause harm to the fetus if used during pregnancy. Women who can become pregnant should use effective contraception during treatment and continue it for at least 5 months after the last dose.

Lactation: The benefits of breastfeeding for the infant should be carefully weighed against the mother’s need for Denosumab therapy and any possible risks to the breastfed child, either from the drug or from the mother’s underlying condition.

Hypersensitivity: Severe allergic reactions, including anaphylaxis, may occur. If a serious reaction develops, Denosumab should be permanently discontinued.

Hypocalcemia: Denosumab may cause severe symptomatic hypocalcemia, and fatal cases have been reported. Correct low calcium levels before starting treatment. The risk is higher in patients with kidney impairment. Monitor calcium levels, especially during the initial weeks, and ensure adequate calcium and vitamin D supplementation.

Osteonecrosis of the Jaw: Cases have been reported. Perform a dental examination before starting therapy and monitor for symptoms. Avoid invasive dental procedures during treatment.

Atypical Femoral Fractures: Unusual fractures of the femur have been reported. Patients with thigh or groin pain should be evaluated to exclude a fracture.

Multiple Vertebral Fractures After Discontinuation: Stopping Denosumab may increase the risk of multiple vertebral fractures. Assess individual risk and consider switching to another antiresorptive treatment after discontinuation.

Serious Infections (Including Skin Infections): Serious infections, sometimes requiring hospitalization, may occur. Patients should seek immediate medical care if symptoms of infection (e.g., cellulitis) appear.

Dermatologic Reactions: Skin conditions such as dermatitis, rash, and eczema have been reported. Consider stopping the drug if severe reactions develop.

Severe Pain: Severe bone, joint, or muscle pain may occur. Discontinue use if symptoms are significant.

Suppression of Bone Turnover: Denosumab may significantly suppress bone remodeling. Monitor patients for complications related to excessive suppression.

Hypercalcemia After Discontinuation (in Specific Patients): High calcium levels may occur after stopping treatment, especially in patients with giant cell tumor of bone or growing skeletons. Monitor and manage appropriately.

Embryo-Fetal Toxicity: Denosumab may harm the fetus. Women of reproductive potential should be informed of the risk and advised to use effective contraception.

Pediatric Patients: Denosumab is not approved for general use in children. It is recommended only for skeletally mature adolescents with giant cell tumor of bone.

Geriatric Patients: No significant differences in safety or effectiveness have been observed between elderly and younger patients.

Renal Impairment: No dose adjustment is required for patients with kidney impairment. However, patients with creatinine clearance below 30 mL/min or those on dialysis have a higher risk of hypocalcemia. Calcium and vitamin D supplementation is recommended, and serum calcium levels should be monitored.

Hepatic Impairment: There are no clinical studies evaluating the effect of liver impairment on the pharmacokinetics of Denosumab.

Inhibiting bone resorption

Denosumab should be stored in a refrigerator at 2°C to 8°C in its original packaging. It must not be frozen. After removal from the refrigerator, it should not be exposed to temperatures above 25°C or direct sunlight and should be used within 14 days. If not used within this period, it should be discarded. The medicine should be protected from light and heat, and vigorous shaking should be avoided.