Treatment of pituitary gigantism with the growth hormone receptor antagonist pegvisomant.

Author(s): Goldenberg N, Racine MS, Thomas P, Degnan B, Chandler W, Barkan A

Affiliation(s): University of Michigan Medical Center, Division of MEND, Department of Internal Medicine, Ann Arbor, Michigan 48109, USA.

Publication date & source: 2008-08, J Clin Endocrinol Metab., 93(8):2953-6. Epub 2008 May 20.

Publication type: Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.

CONTEXT: Treatment of pituitary gigantism is complex and the results are usually unsatisfactory. OBJECTIVE: The objective of the study was to describe the results of therapy of three children with pituitary gigantism by a GH receptor antagonist, pegvisomant. DESIGN: This was a descriptive case series of up to 3.5 yr duration. SETTING: The study was conducted at a university hospital. PATIENTS: Patients included three children (one female, two males) with pituitary gigantism whose GH hypersecretion was incompletely controlled by surgery, somatostatin analog, and dopamine agonist. INTERVENTION: The intervention was administration of pegvisomant. MAIN OUTCOME MEASURES: Plasma IGF-I and growth velocity were measured. RESULTS: In all three children, pegvisomant rapidly decreased plasma IGF-I concentrations. Growth velocity declined to subnormal or normal values. Statural growth fell into lower growth percentiles and acromegalic features resolved. Pituitary tumor size did not change in two children but increased in one boy despite concomitant therapy with a somatostatin analog. CONCLUSIONS: Pegvisomant may be an effective modality for the therapy of pituitary gigantism in children. Titration of the dose is necessary for optimal efficacy, and regular surveillance of tumor size is mandatory.