DENOSUMAB-DSSB
Clinical safety rating: avoid
Contraindicated (not allowed)
Denosumab-dssb is a human monoclonal IgG2 antibody that binds to RANKL (receptor activator of nuclear factor-kappa B ligand), preventing its interaction with RANK on osteoclast precursors and osteoclasts. This inhibits osteoclast formation, function, and survival, thereby decreasing bone resorption and turnover.
| Metabolism | Denosumab-dssb is a monoclonal antibody degraded into small peptides and amino acids via general protein catabolism; not metabolized by cytochrome P450 enzymes. |
| Excretion | Primarily eliminated via reticuloendothelial system catabolism; renal excretion minimal (<1% unchanged). No biliary or fecal excretion of intact denosumab. |
| Half-life | Terminal half-life approximately 26 days (range 20–32 days) in healthy postmenopausal women; supports monthly subcutaneous dosing. |
| Protein binding | No protein binding data available; as a monoclonal antibody, binding to serum proteins is negligible. |
| Volume of Distribution | Approximately 0.06 L/kg (range 0.05–0.07 L/kg), indicating limited extravascular distribution consistent with large protein. |
| Bioavailability | Subcutaneous: Approximately 62% (range 54–70%) after single dose. |
| Onset of Action | Subcutaneous: Reduction in bone turnover markers (e.g., NTX) begins within 12 hours, maximal suppression by 1 month. |
| Duration of Action | After single SC dose, bone turnover markers remain suppressed for ~6 months; clinical effect on bone mineral density persists with continued dosing. |
120 mg subcutaneously every 4 weeks for giant cell tumor of bone; 60 mg subcutaneously every 6 months for osteoporosis; or 120 mg subcutaneously every 4 weeks with supplemental calcium and vitamin D for prevention of skeletal-related events in multiple myeloma or bone metastases from solid tumors.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for any degree of renal impairment. Monitor calcium levels closely in patients with severe renal impairment (CrCl <30 mL/min) or on dialysis due to increased risk of hypocalcemia. |
| Liver impairment | No dose adjustment required for mild or moderate hepatic impairment (Child-Pugh A or B). Not studied in severe hepatic impairment (Child-Pugh C); use with caution. |
| Pediatric use | Safety and efficacy not established in pediatric patients. Not approved for use in children. |
| Geriatric use | No specific dose adjustment based on age. Monitor renal function and calcium levels, as elderly patients may have age-related renal impairment and are at higher risk for hypocalcemia and infections. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
No significant drug interactions Can cause severe hypocalcemia must correct pre-existing hypocalcemia prior to use.
| Breastfeeding | No human data on excretion in breast milk. Denosumab is a large monoclonal antibody (IgG2), likely present in colostrum and breast milk in low levels. M/P ratio not established. Theoretical risk of immunosuppression and bone marrow suppression in the infant. Consider discontinuing breastfeeding or drug based on necessity. |
| Teratogenic Risk | Denosumab is a RANKL inhibitor and is contraindicated in pregnancy. Animal studies show increased fetal loss, skeletal malformations, and delayed ossification. First trimester exposure may disrupt fetal bone development. Second and third trimester exposure can cause fetal skeletal abnormalities and hypocalcemia. Use is not recommended at any trimester. |
■ FDA Black Box Warning
Denosumab-dssb may cause severe hypocalcemia. Correct hypocalcemia prior to initiating therapy. Monitor calcium levels and supplement with calcium and vitamin D as necessary. Cases of osteonecrosis of the jaw (ONJ) and atypical femur fractures have been reported. Discontinue if severe hypersensitivity reactions occur.
| Common Effects | bone metastases |
| Serious Effects |
["Pre-existing hypocalcemia","Known hypersensitivity to denosumab-dssb or any product components","Pregnancy: Denosumab-dssb may cause fetal harm based on animal studies"]
| Precautions | ["Severe symptomatic hypocalcemia","Hypersensitivity reactions including anaphylaxis","Osteonecrosis of the jaw (ONJ): Risk factors include invasive dental procedures, poor oral hygiene, and concomitant medications (e.g., chemotherapy, corticosteroids, antiangiogenics)","Atypical subtrochanteric and diaphyseal femoral fractures","Embryo-fetal toxicity: May cause fetal harm when administered to pregnant women","Multiple vertebral fractures after discontinuation: Evaluate benefit-risk before stopping therapy","Suppression of bone turnover: Monitor for fractures and consider drug holiday after 3-5 years"] |
Loading safety data…
| Fetal Monitoring | Monitor maternal serum calcium and phosphorus levels at baseline and periodically. Fetal monitoring includes ultrasound for skeletal development if exposure occurs. Assess neonatal calcium levels post-delivery. Long-term bone health monitoring in exposed infants. |
| Fertility Effects | In animal studies, female fertility was affected with disruption of estrous cycles and reduced implantation. No human fertility studies. Potential for reversible impairment of ovulation. Contraception recommended during therapy and for 5 months after last dose. |