Alternate-day administration of pegvisomant maintains normal serum insulin-like growth factor-I levels in patients with acromegaly.

Author(s): Jehle S, Reyes CM, Sundeen RE, Freda PU

Affiliation(s): Department of Medicine, Columbia College of Physicians and Surgeons, 630 West 168th Street, New York, New York 10032, USA.

Publication date & source: 2005-03, J Clin Endocrinol Metab., 90(3):1588-93. Epub 2004 Dec 7.

Publication type: Clinical Trial

IGF-I levels normalize in the majority of patients with acromegaly treated with the GH receptor antagonist pegvisomant. To date, the efficacy of pegvisomant has been demonstrated with daily administration of doses ranging from 10 to 40 mg. However, given the known long half-life of the drug in circulation, we hypothesized that dosing less frequently than daily would still maintain the drug's efficacy. We studied 10 patients with active acromegaly treated with pegvisomant. This therapy was begun at 10 mg daily but then titrated up in dose or down to alternate-day dosing to try to maintain serum IGF-I levels in the upper half of the patients' age-adjusted normal range. We found that in five of 10 patients, serum IGF-I levels remained normal on less frequent than daily pegvisomant. Signs and symptoms of the disease and a disease-related morbidity, insulin resistance, remained improved in these patients. We demonstrate for the first time the continued efficacy of alternate-day administration of pegvisomant.