On Dec. 19, 2022, the U.S. Food & Drug Administration (FDA) approved subcutaneous abaloparatide (Tymlos) for the treatment of men with osteoporosis at high risk of fracture, as well as adult patients for whom other osteoporosis therapies have proved ineffective or can’t tolerate other therapies.1
The FDA had previously approved abaloparatide for the treatment of postmenopausal women with osteoporosis at high risk of fracture.2
Abaloparatide is an analog of parathyroid hormone-related peptide [PTHrP(1-34)].3 High fracture risk is defined as a history of osteoporotic fracture or multiple risk factors for fracture, such as age, low bone mineral density (BMD) and previous fragility fracture.4
This latest FDA approval was based on findings of a 12-month, safety and efficacy study of subcutaneous abaloparatide in men with osteoporosis (ATOM; NCT03512262).5 The multicenter, phase 3 study was randomized and double-blinded.
In the study, researchers evaluated 80 μg of abaloparatide given daily as a subcutaneous injection to men with osteoporosis (n=149) aged 40–85 years old. This group was compared with a group of men with osteoporosis who received placebo injections (n=79). All patients also took daily supplemental calcium (500–1,000 mg) and vitamin D (400–800 IU).
The study’s primary outcome measure was the change in percentage from baseline in BMD of the lumbar spine at month 12. Secondary outcome measures were the change in percentage from baseline in BMD of the total hip and femoral neck at month 12, the change in percentage from baseline in BMD of the lumbar spine at month six and treatment-associated emergent adverse events associated with hypercalcemia within 13 months.
Results
Most men in the study were white (approximately 95%); 4% were Asian, and 0.4% were Black. Another 16% of study patients identified as Hispanic. At baseline, mean T-scores at the lumbar spine and femoral neck were -2.1, and mean T-scores at the total hip were -1.7.
At month 12, treatment with abaloparatide had led to significant increases in BMD at the lumbar spine, total hip and femoral neck (P<0.0001), compared with placebo. For the primary efficacy measure of the lumbar spine, the change in percentage in BMD from baseline was 8.5% for patients treated with abaloparatide and 1.2% for patients who received the placebo—a 7.3% treatment difference (99% confidence interval [CI] 5.1%, 9.6%; P<0.0001). No differences in the effect of abaloparatide were seen across subgroups defined by ethnicity, race, age, geographic region, BMD at baseline or the presence or absence of prior fracture.