Two-Agent Osteoporosis Treatment Boosts BMD

 Two sequential osteoporotic medications were better than one at bolstering bone mineral density (BMD), new data showed.

In a post-hoc analysis of the ACTIVExtend study, postmenopausal women with osteoporosis who received 18 months of abaloparatide (Tymlos) treatment followed by 24 months of alendronate (Binosto, Fosamax) treatment saw significant increases in total hip areal BMD compared with women who only received 24 months of alendronate (6.42% vs 2.88%, P<0.001), reported Renaud Winzenrieth, PhD, of Galgo Medical in Barcelona.

"These results support the use of abaloparatide as initial treatment in sequential therapy with alendronate in postmenopausal women with osteoporosis at high-risk for fracture," Winzenrieth explained in a presentation at the American Association of Clinical Endocrinology (AACE) virtual meeting.

"This treatment paradigm is consistent with recommendations by organizations such as AACE or ESCEO, which suggests considering a bone anabolic agent first followed by a potent antiresorptive in certain high-risk patients," he stated.

From baseline to month 43, those on abaloparatide plus alendronate saw significantly greater gains in trabecular volumetric BMD of the total hip and hip subregions versus alendronate alone, measured with research-only DXA-based 3D modeling:

• Total hip: 6.66% greater change (95% CI 4.83-8.50%)
• Femoral neck: 8.00% (95% CI 6.12-9.88%)
• Intertrochanteric: 6.75% (95% CI4.06-9.43%)
• Upper shaft: 7.78% (95% CI 3.96-11.60%)

While both treatment groups saw improvements in cortical thickness, women who received abaloparatide followed by alendronate saw significantly greater increases in several variables versus alendronate-alone, according to the 3D DXA scans (all P<0.001):

• Total hip cortical thickness: 2.32% vs 1.14% (alendronate alone)
• Cortical volumetric BMD: 3.41% vs 1.86%
• Cortical surface BMD: 5.82% vs 3.0%

Also by month 43, the abaloparatide plus alendronate group also saw significantly greater increases in cross-sectional moment of inertia, section modulus, and buckling ratio at all three subregions tested -- the femoral neck, intertrochanteric, and upper shaft.

The original ACTIVE trial included postmenopausal women who received 80 μg daily of subcutaneous abaloparatide for 18 months, and subsequently crossed over to the extension phase of the trial to receive 70 mg of weekly alendronate treatment for an additional 24 months. They were compared with a group of women who received placebo for 18 months, followed by 70 mg of weekly alendronate. A total of 250 women in the abaloparatide and placebo groups also underwent 3D DXA scanning.

Winzenrieth explained that this DXA-based 3D modeling technology, known as the 3D Shaper, is relatively new, and not currently approved for clinical practice use in the U.S. He said the developer is in the process of applying for FDA approval, and expects the device to be cleared within the year.

The technology uses standard 2D DXA scan images of the proximal femur to create a 3D model, providing separate assessments of trabecular and cortical bone. Winzenrieth added that the 3D Shaper device, which connects to a clinical center's network or DXA computer, is compatible with almost all manufacturers DXA scanners.

Breaking apart assessments of trabecular and cortical bone can help guide treatment options "because you have some treatments that improve one compartment more than another, or you have the opposite effect of the teriparatide [Forteo], where you have this increase of the cortical thickness and concomitant decrease of the cortical density," Winzenrieth said.

"You can evaluate more precisely the effect of the drugs, or the effect of the disease, or if you have a concomitant effect of both," he added, calling it a more "personalized" approach to treating osteoporosis.

Disclosures

The study was funded by Radius Health.

Winzenrieth disclosed being an employee and shareholder of Galgo Medical (developer of 3D-Shaper) and paid consultant of Radius Health.

Primary Source

American Association of Clinical Endocrinology

Source Reference: Winzenrieth R, et al "Sequential therapy of abaloparatide followed by alendronate as assessed by DXA-Based 3D modeling in postmenopausal women with osteoporosis" AACE 2021.

https://www.medpagetoday.com/meetingcoverage/aace/92852