Prolia (Denosumab) Pre-Surgery Hold Window: What Clinicians Need to Know

What the label says about surgery

Prolia is denosumab 60 mg given subcutaneously every 6 months by a healthcare provider for osteoporosis and bone loss; Xgeva, 120 mg every 4 weeks for cancer-related bone disease, is a separate product and the two should not be given together [1][3]. The Prolia label does not set an interval for stopping it before elective surgery [1].

The closest thing in it to perioperative advice is the osteonecrosis of the jaw section: a routine oral exam should be performed before starting, a dental examination with preventive dentistry is recommended first in patients with risk factors, and for patients who need invasive dental procedures such as tooth extraction, dental implants or oral surgery, the label says clinical judgment of the treating physician or oral surgeon should guide the management plan [1].

The FREEDOM trial paper reported no increase in delayed fracture healing with denosumab over 3 years [5].

What happens when a dose is late or skipped

Denosumab is a RANK ligand inhibitor: it binds RANKL and blocks osteoclast formation and activity, reducing bone resorption [1]. Its effect is reversible. The label states that bone turnover rises above pretreatment levels about 9 months after the last Prolia dose and returns to pretreatment values about 24 months after, and that bone mineral density returns to pretreatment values within about 18 months; the clinical studies section puts it at approximately baseline within 12 months [1].

In a 24-month off-treatment extension of a phase 3 trial in 256 postmenopausal women with low bone mass, serum CTX rose above baseline within 3 months of stopping denosumab and P1NP within 6 months, and both returned to baseline by month 48 [6].

After Prolia stops, bone turnover rises and vertebral fracture risk increases [1][4]. In a post hoc analysis of FREEDOM and its extension, 1,001 participants who stopped denosumab after at least two doses had a vertebral fracture rate that rose from 1.2 per 100 participant-years on treatment to 7.1 off treatment, close to the 8.5 seen after stopping placebo; among those with at least one off-treatment vertebral fracture, 60.7% of denosumab stoppers had more than one, versus 38.7% after placebo [4]. The label reports that in the phase 3 trial 6% of women who stopped and stayed in the study had new vertebral fractures and 3% had multiple new vertebral fractures, with mean onset 17 months and a range of 7 to 43 months, and that a prior vertebral fracture predicts multiple fractures [1]. FDA's 2024 safety communication states that the risk of bone fracture, including in the spine, is increased after stopping, skipping or delaying Prolia [2].

Treatment duration may matter. In a later post hoc analysis of women who stopped placebo (327), denosumab for 3 years or less (262) or denosumab for more than 3 years (213), annualized multiple vertebral fracture rates were 3.6, 2.9 and 7.5 per 100 patient-years, and longer duration was associated with multiple fractures (odds ratio 3.0); the authors describe the analysis as exploratory [7].

Calcium and hypocalcemia

Prolia can cause severe hypocalcemia and fatal cases have been reported, pre-existing hypocalcemia must be corrected before treatment starts, and the label instructs calcium 1,000 mg daily with at least 400 IU vitamin D daily for all patients [1]. In FREEDOM, serum calcium below 8.5 mg/dL at any visit occurred in 1.7% of women on Prolia versus 0.4% on placebo, with the nadir about day 10 after dosing; in a 55-person study across renal function levels without calcium or vitamin D supplementation, calcium below 7.5 mg/dL or symptomatic hypocalcemia occurred in none of the normal-function subjects, 10% with creatinine clearance 50 to 80 mL/min, and 29% in both the creatinine clearance below 30 mL/min and hemodialysis groups [1].

For patients predisposed to hypocalcemia (hypoparathyroidism, thyroid or parathyroid surgery, malabsorption, small bowel excision, or other calcium-lowering drugs), the label says to assess serum calcium, phosphorus and magnesium 10 to 14 days after an injection [1]. The boxed warning covers advanced kidney disease, meaning eGFR below 30 mL/min/1.73 m2, including dialysis: in female dialysis-dependent Medicare patients the 12-week cumulative incidence of severe hypocalcemia was 41.1% with denosumab versus 2.0% with oral bisphosphonates [1][2]. FDA lists hypocalcemia symptoms as confusion, seizures, irregular heart rhythm, fainting, face twitching, uncontrolled muscle spasms, and weakness, tingling or numbness [2].

Infection and cellulitis

In FREEDOM the incidence of nonfatal serious infections was 4.0% with Prolia versus 3.3% with placebo, while infections resulting in death occurred in 0.2% of both groups [1]. The label warns that serious infections including skin infections may occur, including those leading to hospitalization, and says patients should be advised to seek prompt medical attention for signs or symptoms of infection including cellulitis [1].

If Prolia has to stop around the operation

The label states that patients who discontinue Prolia should be transitioned to an alternative antiresorptive agent [1]. The European Calcified Tissue Society position statement, based on a systematic review, advises that denosumab should not be stopped without considering alternative treatment, that bisphosphonate therapy should be considered for lower-risk patients who stop to reduce or prevent the rebound in bone turnover, and that the optimal bisphosphonate regimen after denosumab is unknown [8].

One randomized trial compared zoledronate with two further denosumab injections. In that 2-year trial, 57 women with postmenopausal osteoporosis who had taken denosumab for a mean of 2.2 years were randomized to a single 5 mg zoledronate infusion given 6 months after the last denosumab injection (27 women) or to two further 60 mg denosumab injections (30 women). At 24 months lumbar spine bone mineral density was not different from baseline in the zoledronate group but had fallen 4.82% from the 12-month value in the denosumab group; three women in the denosumab group had vertebral fractures versus one in the zoledronate group. The primary endpoint was bone mineral density [9].

Xgeva runs on a different schedule

Xgeva is 120 mg every 4 weeks for skeletal-related events in multiple myeloma and bone metastases, giant cell tumor of bone, and hypercalcemia of malignancy, and it carries no boxed warning [3]. Its label says to evaluate each patient's vertebral fracture risk when treatment stops, and in giant cell tumor to monitor for hypercalcemia, which has been reported within the first year after stopping [3].

What remains unsettled

How much a specific bridging regimen reduces rebound fracture risk for an individual patient is not established; the ECTS review notes that strong evidence for measures to prevent bone loss after denosumab is stopped is lacking [8].