The following is a summary of “Long-term Pegvisomant Therapy of Acromegaly: Effects on Bone Density, Turnover and Microstructure Using HRpQCT,” published in the June 2024 issue of Endocrinology by Kuker, et al.

Fracture risk is heightened in patients with active and remitted acromegaly, with persistent abnormalities in bone microstructure despite biochemical control post-surgery. The impact of pegvisomant, a growth hormone receptor antagonist, on bone microstructure remained uncertain.

About 25 patients with acromegaly (15 men, 10 women) were studied. In 20 patients, areal bone mineral density (BMD) and bone turnover markers (BTMs) were longitudinally evaluated before and during pegvisomant treatment. Around 17 patients on long-term pegvisomant were cross-sectionally assessed for volumetric BMD, microarchitecture, stiffness, and failure load of the distal radius and tibia using high-resolution peripheral quantitative computed tomography (HRpQCT). The results were compared to healthy controls and two comparison groups of patients with non-pegvisomant-treated acromegaly (in remission and with active disease), matched for other therapies and characteristics.

In the longitudinal study, areal BMD improved at the lumbar spine but decreased at the hip in men after a median of approximately 7 years of pegvisomant. In the cross-sectional study, patients on a median of approximately 9 years of pegvisomant showed significantly larger bones, lower trabecular and cortical volumetric density, and disrupted trabecular microarchitecture compared to healthy controls. Microstructure was similar between the pegvisomant group and the acromegaly comparison groups. BTMs decreased initially, then stabilized over time.

The study, the first to explore bone microstructure in patients with pegvisomant-treated acromegaly, identified deficits in volumetric BMD and peripheral skeleton microarchitecture. BTM levels remained stable with long-term therapy. These deficits in bone quality, as detected by HRpQCT, may contribute to fragility in treated acromegaly.

Reference: academic.oup.com/jes/article/8/6/bvae079/7648823