Zoledronic acid (Zometa), a new bisphosphonate, has been approved by the FDA for intravenous (IV) treatment of hypercalcemia of malignancy.

The FDA, which recently approved subcutaneous (SC) administration of denosumab (Prolia – Amgen) for treatment of postmenopausal osteoporosis,1 has now approved the same drug with a different brand name (Xgeva – Amgen) and dosage for prevention of skeletal-related events (such as pathologic fracture, spinal cord compression or radiation to bone) in patients with bone metastases from solid tumors. Denosumab is a fully human anti-RANK ligand antibody that inhibits the formation, activation and survival of osteoclasts.2A prospective, randomized, double-blind trial in 1901 patients with bone...

Zoledronic acid (Reclast - Novartis) is the first bisphosphonate approved by the FDA for once-yearly intravenous (IV) treatment of osteoporosis in postmenopausal women. Reclast is also approved for treatment of Paget's disease. Another IV formulation of zoledronic acid (Zometa) is approved for treatment of hypercalcemia of malignancy, multiple myeloma and bone metastases from solid tumors.

Radium Ra 223 dichloride (Xofigo – Bayer), a radiotherapeutic drug, has been approved by the FDA for intravenous treatment of castration-resistant prostate cancer with symptomatic bone metastases and no known visceral metastatic disease.

A once-weekly 35-mg oral formulation of the bisphosphonate risedronate (Actonel) has been approved by the FDA for prevention and treatment of postmenopausal osteoporosis. A once-weekly formulation of alendronate (Fosamax) was approved last year (Medical Letter 2001; 43:26). Bisphosphonates bind to the mineral surface of bone and decrease osteoclast activity, inhibiting the resorption phase of the bone turnover cycle. These drugs are not metabolized and remain bound to bone for several weeks.

A 10-year study of daily oral alendronate (Fosamax) and a 7-year study of daily oral risedronate (Actonel) indicate that both drugs maintained increases in bone mineral density (BMD) and decreases in markers of bone remodeling throughout the study period. Both drugs are now more commonly taken once weekly. Available data are insufficient to compare fracture rates with alendronate and risedronate, and fracture rates are considered the most important endpoint in osteoporosis studies. Recent reports of severe pain and jaw osteonecrosis with these drugs are disturbing.

Ibandronate (Boniva - Roche) is the first bisphosphonate approved by the FDA for intravenous (IV) treatment of osteoporosis in postmenopausal women. It is given as a bolus injection once every 3 months. Ibandronate is also available as an oral once-a-month 150-mg tablet and as a daily 2.5-mg tablet.

The FDA has approved romosozumab-aqqg (Evenity – Amgen), a sclerostin inhibitor, for once-monthly subcutaneous (SC) treatment of osteoporosis in postmenopausal women who are at high risk for fracture (history of osteoporotic fracture or multiple risk factors for fracture) or who have failed or cannot tolerate other drugs for this indication. Romosozumab is the first sclerostin inhibitor to be approved in the US and the third drug for treatment of postmenopausal osteoporosis that stimulates bone formation; the parathyroid hormone (PTH) receptor agonists abaloparatide (Tymlos) and...

Pharmacologic treatment is recommended for postmenopausal women who have bone density T-scores (standard deviations from normal mean values in the spine, femoral neck, total hip, or distal radius) of -2.5 or below, T-scores between -1.0 and -2.5 with a history of fragility (low-trauma) fracture of the hip or spine, or T-scores between -1.0 and -2.5 with a FRAX 10-year probability of ≥3% for hip fracture or ≥20% for major osteoporotic fracture.