In April 2017, Abaloparatide (Tymlos™), developed by Radius Health, received its first global approval in the US for the treatment of postmenopausal women with osteoporosis at high risk for fracture. Abaloparatide is administered subcutaneously into the peri-umbilical region of the abdomen. The agent is a synthetic human parathyroid hormone-related peptide (PTHrP) analogue; specifically, it is a parathyroid hormone type 1 receptor agonist (PTH1R) with osteoanabolic activity.
Abaloparatide is dispensed as prefilled single-use pens for patient self-administration at about the same time each day. In cases of inadequate dietary intake, concomitant vitamin D and calcium supplements are advised.
Osteoporosis is considered a public health concern since an estimated 200 million people (male and female) worldwide are affected by the disease. According to the International Osteoporosis Foundation, approximately a third of all postmenopausal females in both the US and Europe have osteoporosis; and approximately 40% will experience at least one fragility fracture.
“Fragility fractures should be viewed as sentinel events which require urgent evaluation and treatment because after that first fragility fracture, patients are at greater risk for subsequent fractures,” said John Bilezikian, M.D., Professor of Medicine and Pharmacology at the College of Physicians & Surgeons, Columbia University, New York City. “The FDA’s approval of TYMLOS represents an important step in our ability to treat this serious and complex disease and, in the process, address this urgent public health crisis.”
Robert Ward, President and Chief Executive Officer of Radius Health agreed, when he stated that, “We believe that an osteoporotic fracture can be a life-altering event for a woman and her family. Osteoporosis in postmenopausal women represents a significant disease burden for which diagnosis and treatment should be healthcare priorities.”
Abaloparatide is said to have greater bone-building and less calcium-mobilising potential than teriparatide, another synthetic parathyroid hormone analogue, marketed some 15 years ago in the US. And although abaloparatide will provide another treatment option for women with high-risk osteoporosis, both have limited, recommended treatment durations, after which the approach could switch to include the prevention of bone loss by agents such as bisphosphonates. In this case the greater bone-building effect of abaloparatide will provide an advantage.
Abaloparatide carries a black box warning concerning the risk of osteosarcoma; this oncogenic effect was observed in male and female rats receiving up to 28 times the recommended human dose. The likelihood of developing osteosarcoma in humans is unknown, however, use in patients with an increased risk of osteocarcinoma is not recommended. Furthermore, cumulative use of abaloparatide, as with other parathyroid hormone analogues, is not recommended for more than two years within a patient’s lifetime.
Abaloparatide subcutaneous injection is also under regulatory review in Europe for the same indication. In addition, a transdermal, micro-needle, patch formulation is under clinical investigation.
Image credit: STEVE GSCHMEISSNER / science photo library / AGEN