ORF34-06 - Effects of Sequencing to Antiresorptive Therapy after Abaloparatide or Teriparatide on Hip Fracture Risk: A Retrospective, Real-World Study

Background
The parathyroid hormone analogs, abaloparatide (ABL) and teriparatide (TPTD), are anabolic agents used for the treatment of osteoporosis. Current treatment guidelines advise following anabolic therapy with antiresorptive (AR) therapy to maintain and enhance antifracture efficacy. This updated study assessed the effect of postanabolic AR therapy on hip fracture outcomes in patients prescribed ABL and TPTD.

Methods
This updated analysis used anonymized patient claims data from ICON’s Symphony Health Patient Source Integrated Dataverse. Men and women ≥50 years of age were included who had an initial prescription filled for ABL or TPTD (≥6 mo) from January 1, 2018 through June 30, 2021, and medical or pharmacy records for ≥1 year prior to and 3 years after discontinuing anabolic therapy, or up to June 30, 2025, whichever is earlier. Patients were grouped by postanabolic AR use (AR therapy started within 1 year of the anabolic vs no AR therapy), and logistic-regression propensity score matching was used to create matched groups. Hip fracture incidence over 3 years with postanabolic AR vs without AR was calculated based on the number of events per 100 patient-years and compared using a Poisson regression model.

Results
After propensity score matching, 5914 ABL (2957 per group, >98% women, median age: 65 years) and 6286 TPTD (3143 per group, >86% women, median age: 67 years) were included. 67% of patients received ABL or TPTD for >12 months, and the mean treatment duration in both groups was 15 months. In both groups during the 3-year postanabolic period, 185 hip fractures (77 with postanabolic AR, 108 without AR) were recorded for 12,200 patients. The rate of hip fracture per 100 patient-years was lower with postanabolic AR therapy vs without postanabolic AR therapy (ABL: 0.35 vs 0.53; TPTD: 0.49 vs 0.65; ABL+TPTD: 0.43 vs 0.59). Hip fracture risk reductions (risk ratio [95% CI]) in those who received vs did not receive postanabolic AR therapy were as follows: ABL: 0.67 (0.42, 1.05), P=0.08; TPTD: 0.76 (0.52, 1.11), P=0.16; ABL+TPTD: 0.72 (0.54, 0.96), P=0.03.

Conclusions
This real-world study evaluated the effect of postanabolic AR therapy on hip fracture outcomes in patients prescribed ABL and TPTD. Hip fracture risk was reduced in ABL and TPTD patients with postanabolic AR therapy vs those without, highlighting the need for an AR after anabolic therapy to ensure longer-term protection against hip fracture and support current treatment recommendations.