The Food and Drug Administration (FDA) has approved Tymlos (abaloparatide; Radius Health) subcutaneous injection for the treatment of postmenopausal women with osteoporosis at high risk for fracture defined as a history of osteoporotic fracture, multiple risk factors for fracture, or patients who have failed or are intolerant to other available osteoporosis therapy.
Abaloparatide is a parathyroid hormone related peptide [PTHrP(1-34)] analog which acts as an agonist at the PTH1 receptor (PTH1R). This results in activation of the cAMP signaling pathway in target cells. In animal studies, abaloparatide had an anabolic effect on bone, demonstrated by increases in bone mineral density and bone mineral content that correlated with increases in bone strength at vertebral and/or nonvertebral sites.
The efficacy of Tymlos for the treatment of postmenopausal osteoporosis was evaluated in an 18-month, randomized, multicenter, double-blind, placebo-controlled trial (ACTIVE) in postmenopausal women aged 49–86 years (mean age of 69) who were randomized to receive Tymlos 80mcg (n=824) or placebo (n=821) given subcutaneously once daily. The primary endpoint was the incidence of new vertebral fractures in patients treated with Tymlos compared to placebo. Patients treated with Tymlos had a significant reduction in the incidence of new vertebral fractures compared to placebo group at 18 months (0.6% Tymlos vs. 4.2% placebo, P<0.0001). The absolute risk reduction in new vertebral fractures was 3.6% at 18 months and the relative risk reduction was 86% for Tymlos compared to placebo.
Tymlos carries a boxed warning regarding the risk of osteosarcoma, although this risk was just observed in animals; it is unknown whether the drug will cause osteosarcoma in humans. The use of Tymlos is not recommended in patients at increased risk for osteosarcoma (ie, Paget’s disease of bone, unexplained elevations of alkaline phosphatase, open epiphyses, bone metastases, skeletal malignancies, hereditary disorders predisposing to osteosarcoma, prior external beam or implant radiation therapy involving the skeleton). In addition, cumulative use of Tymlos and parathyroid hormone analogs (ie, teriparatide) for >2 years during a patient’s lifetime is not recommended.
Tymlos will be available in May as a pre-assembled single-patient-use disposable pen; each pen contains 3120mcg of abaloparatide in 1.56mL (2000mcg/mL) and provides a 30-day supply.
For more information call (866) 896-5674 or visit Radiuspharm.com.