LB-OR01-New Discoveries in Bone Health and Disease
Presentation Start Time: 12:00 PM
Room 6F (San Diego Convention Center)
Abaloparatide (ABL) is an investigational osteoanabolic PTHrP analog being developed for the treatment of postmenopausal osteoporosis (PMO). In the ACTIVE double-blind, placebo-controlled (PBO) Phase 3 fracture prevention trial, 2463 PMO women were randomized to receive 18-months of either daily ABL 80-mcg SC, PBO SC or open label teriparatide (TPT) 20-mcg SC. All patients (PTS) received calcium and vitamin D supplements. 2,463 PTS were randomized (ITT population) and 1,901 (77.9%) completed. The groups were well matched for baseline demographics. PTS were 68.8 years old and the mean BMI was 25.1. 16.3% of PTS had 1 vertebral fracture, 28.2% had 2 or more vertebral fractures and 46.8% had at least 1 non-vertebral fracture. The mean spine, femoral neck and total hip baseline T-scores were -2.90, -2.14 and -1.90, respectively. Among the 2,118 PTS who had baseline and post-therapy X-rays, the fracture rate (FR) among those receiving ABL (n=690) was 0.58%, representing a reduction of new incident vertebral FR by 86% as compared to PBO PTS [n=711, FR 4.22%; (p<0.0001)]. The TPT group FR of 0.84% (n=717) was reduced by 80% (p<0.0001 versus PBO). ABL reduced non-vertebral fracture (Kaplan-Meier estimated (KM) FR=2.7%, hazard ratio=0.57, p=0.0489) and clinical fractures (KM FR=3.9%, hazard ratio=0.55, p=0.0112) versus PBO (KM non-vertebral FR=4.7%, KM clinical FR=8.3%). TPT was not significantly different from PBO in non-vertebral fracture (KM FR=3.3%, hazard ratio=0.72, p=0.2157) or clinical fracture (KM FR=4.8%, hazard ratio=0.71, p=0.1127). For wrist fractures ABL (n=824, KM FR 0.5%) and TPT (n=818, KM FR 2.0%) were not were significantly reduced compared to PBO (n=821, KM FR 1.5%); wrist FR was significantly less in ABL than the TPT group (p=0.0149). BMD increased more in ABL and TPT-treated PTS compared to PBO at the spine, femoral neck and hip at 6, 12 and 18 months (p<0.0001 for all comparisons). ABL also increased BMD at the hip at months 6, 12 (both p<0.0001) and 18 (p=0.0003), in the femoral neck at 6, 12 (both p<0.0001) and 18 (p=0.0016) and in the spine at 6 (p<0.0001) and 12 (p=0.0087) significantly more than TPT. ABL was well tolerated the most frequently reported adverse events were back pain, arthralgia, upper respiratory tract infection, hypercalciuria and dizziness. The overall incidence of hypercalcemia (HPC) based on albumin corrected serum calcium measured pre and post injection (4 hours) were 0.37%, 3.41%, and 6.36% for the PBO, ABL and TPT groups, respectively. Both ABL and TPT groups had significantly higher rates of HPC than PBO (p<0.0001), but for ABL was significantly less frequent than for TPT (p=0.0055). These results demonstrate that ABL reduces the incidence and risk of vertebral, non-vertebral, and clinical fractures in in women with PMO and suggest that ABL may prove to be an effective and safe treatment option in the management of PMO.
Disclosure: PDM: Principal Investigator, Radius. BZL: Principal Investigator, Radius. GH: Employee, Radius, Employee, Radius. EL: Principal Investigator, Radius. PA: Principal Investigator, Radius. TH: Principal Investigator, Radius. SM: Principal Investigator, Radius. BSN: Principal Investigator, Radius. AK: Principal Investigator, Radius. JS: Principal Investigator, Radius. CAZ: Principal Investigator, Radius. IV: Principal Investigator, Radius. ZV: Principal Investigator, Radius. BJ: Principal Investigator, Radius. CAK: Principal Investigator, Radius. FM: Principal Investigator, Radius. AGH: Employee, Radius, Employee, Radius. GCW: Employee, Radius, Employee, Radius. MYH: Employee, Radius, Employee, Radius. BJR: Collaborator, Radius. LAR: Collaborator, Radius. CC: Collaborator, Radius.
*Please take note of The Endocrine Society's News Embargo Policy at https://www.endocrine.org/news-room/endo-annual-meeting
Sources of Research Support:
Radius Health Inc.