Denosumab/teriparatide superior to either treatment alone

BALTIMORE —Combined denosumab and teriparatide demonstrated superior efficacy compared with either treatment alone for patients at high risk for fractures, according to data presented at ASBMR 2013.

“The most significant finding is the increase in bone density at the hip, femoral neck and spine. This was greater in women treated with both drugs vs. either one alone, and the magnitude of bone density was greater than what can be achieved with any currently approved medication for osteoporosis,” Benjamin Z. Leder, MD, associate professor of medicine at Harvard Medical School, told Endocrine Today.

Leder and colleagues included 100 postmenopausal women aged 51 to 91 years with a high fracture risk who did not receive oral bisphosphonates in the past 6 months or ever taken parenteral bisphosphonates or teriparatide in the study. They were randomly assigned to teriparatide (Forteo, Lilly) 20 mcg subcutaneously per day, denosumab (Prolia, Xgeva; Amgen) 60 mg subcutaneously every 6 months or both for 24 months.

Benjamin Z. Leder

Although data were recently published focusing on year 1 of this study, the presentation at ASBMR 2013 showed the data from the subsequent year, Leder told Endocrine Today.

Patients were matched for clinical characteristics, including bone mineral density at baseline, and 83 finished all study visits.

The 1-year data indicate mean changes in posterior-anterior spine BMD increased more in the combination group (12.7%) compared with either the teriparatide (9.5%, P<.001) or denosumab (8.3%, P<.001) groups. Femoral neck BMD also increased more in the combination group (6.4%) compared with the teriparatide (2.8%, P=.002) and denosumab (4.1%, P=.028) groups, according to data.

Moreover, total hip BMD increased more in the combination group (6.1%) compared with the teriparatide (2%, P<.001) or denosumab groups (3.2%, P<.001).

BMD at the one-third distal radius increased similarly in the denosumab (2%) and combination groups (2.4%). However, it decreased –1.7% in the teriparatide group (P<.001 for both between-group teriparatide comparisons), according to data.

Leder said denosumab alone and teriparatide alone produced similar changes at the spine (P=.831) and femoral neck (P=.194). However, denosumab increased total hip BMD more than teriparatide (P=.005).

“This research is important because teriparatide doesn’t tend to exert its effects on hip bone density until the second year,” Leder said.

However, there is a caveat, according to Leder. The study examined the effects on bone density, but not the prevention of fractures. Therefore, larger studies will be necessary to confirm that the combination is useful in terms of reducing fractures more than other approaches. – by Samantha Costa

For more information:

Leder BZ. John H. Carstens Memorial Distinguished Orals – Osteoporosis Treatment #1019. Presented at: the American Society for Bone and Mineral Research 2013 Annual Meeting; Oct. 4-7, 2013; Baltimore.

Disclosure: Leder reports financial ties with Amgen, Lilly and Merck.