The growth hormone receptor antagonist pegvisomant may be used in patients with acromegaly who are not cured by transsphenoidal surgery and resistant to somatostatin analogues.

Ramos-Leví et al. evaluated the outcomes of long term pegvisomant therapy for acromegaly in 64 patients from tertiary care referral hospitals in Spain. Patients were followed-up for 9 (4.1–10.4) years after the first administration of pegvisomant in a clinical setting. Insulin-like growth factor-1 normalisation was achieved in almost 90% of patients. Tumour growth was seen in about 9% of patients, none of whom had received prior radiotherapy.

Loss of biochemical control (‘escape’) occurred in approximately 16% of patients, but could be relatively easily overcome by adjusting therapy. Potential underlying causes of escape included tumour regrowth, lipohypertrophy, previous treatment modifications, concomitant menopause, change in testosterone administration and acute concomitant administration of high glucocorticoid doses.

The authors give reassurance regarding the efficacy and safety of long term pegvisomant, and highlight the importance of close follow-up and adequate pegvisomant dose titration.

Read the full article in Clinical Endocrinology 84 540–550