Xgeva Denosumab Injection

1. Indications and Usage
Osteoporosis (Prolia): Treatment of postmenopausal women with osteoporosis at high risk for fracture; treatment of men with osteoporosis at high risk for fracture.
Bone Metastases (Xgeva): Prevention of skeletal-related events (SREs) in patients with multiple myeloma or solid tumors with bone metastases.
Giant Cell Tumor of Bone (Xgeva): Treatment of adults and skeletally mature adolescents with giant cell tumor of bone that is unresectable or where surgical resection is likely to result in severe morbidity.
Skeletal Reduction: Reduction in bone loss in men receiving androgen deprivation therapy for non-metastatic prostate cancer; reduction in bone loss in women receiving adjuvant aromatase inhibitor therapy for breast cancer.
2. Dosage and Administration
Route of Administration:
For Subcutaneous Injection ONLY (thigh, upper arm, or lower abdomen).
Recommended Dosage:
Osteoporosis (60 mg): 60 mg administered once every 6 months.
Bone Metastases & Giant Cell Tumor (120 mg): 120 mg administered once every 4 weeks.
Supplementation:
All patients must be supplemented with calcium and vitamin D to prevent hypocalcemia.
3. Mechanism of Action
RANKL Inhibition:
Denosumab is a human IgG2 monoclonal antibody that binds with high affinity and specificity to the Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL).
Blocking Signaling:
By binding to RANKL, denosumab prevents it from interacting with its receptor (RANK) on the surface of osteoclast precursors and mature osteoclasts.
Downstream Effect:
This inhibition prevents osteoclast formation, function, and survival, thereby reducing bone resorption and increasing bone mass and strength.
4. Safety and Warnings
Hypocalcemia (Boxed Warning):
Serious and sometimes fatal hypocalcemia can occur. Risk is highest in patients with severe renal impairment (eGFR <30 mL/min).
Requirement: Correct hypocalcemia and other disturbances of bone and mineral metabolism before dosing.
Serious Infections:
Increased risk of serious infections (e.g., cellulitis) has been observed; monitor patients with active infections or those on immunosuppressants.
Osteonecrosis of the Jaw (ONJ):
Cases of ONJ have been reported. Risk factors include invasive dental procedures, cancer, and prolonged use.
Atypical Femoral Fractures:
Rare cases of atypical subtrochanteric and diaphyseal femoral fractures have been reported.
Rebound Phenomenon:
Discontinuation of denosumab may be associated with multiple vertebral fractures (rebound effect). Alternative therapy should be considered upon discontinuation.
5.Adverse Reactions
Most Common (Osteoporosis):
Back pain, extremity pain, musculoskeletal pain, hypercholesterolemia, and bladder infection.
Most Common (Bone Metastases):
Fatigue, weakness, musculoskeletal pain, diarrhea, nausea, and rash.
6.Drug Interactions
No CYP Interaction:
As a biologic molecule, denosumab does not interact with CYP450 enzymes.
Immunosuppressants:
Caution is advised when used concomitantly with other immunosuppressive therapies (e.g., corticosteroids, rituximab) due to cumulative infection risk.
7.Pharmaceutical Information
Chemical Composition:
Active Ingredient: Denosumab.
Available Strength:
Prolia: 60 mg/1 mL (Prefilled syringe).
Xgeva: 120 mg/1.7 mL (Single-dose vial).
Appearance: Clear to slightly opalescent, colorless to pale yellow solution.
Storage: Store at 2°C to 8°C (36°F to 46°F).