BMI and duration of treatment influence the pegvisomant dose in active acromegaly after long-term follow-up

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 88-129-Acromegaly & Prolactinoma
Clinical
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-109
Antonio Bianchi*1, Pietro Maffei2, Silvia Grottoli3, Giorgio Arnaldi4, Marta Ragonese5, Maria Rosaria Ambrosio6, Teresa Porcelli7, Antonella Giampietro8, Maria Chiara Zatelli9, Salvatore Cannavo10, Marco Boscaro11, Nicola Sicolo12, Andrea Giustina13, Ezio G G M Ghigo14, Alfredo Pontecorvi15 and Laura De Marinis15
1Catholic University, School of Medicine, Rome, Italy, 2University of Padova, Padova, Italy, 3University of Turin, Turin, Italy, 4Clinica di Endo, Ancona, Italy, 5University of Messina, Messina, Messina, Italy, 6Endocrinology, University of Ferrara, Ferrara, Italy, 7University of Brescia, Brescia, Italy, 8Catholic Univ, Rome, Italy, 9University of Ferrara, Ferrara, Italy, 10Section of Endocrinology, Messina, ME, Italy, 11Univ Politecnica Marche, Ancona, Italy, 12Clinica Medica III Univ PD, Verona, Italy, 13University of Brescia, Montichiari, Italy, 14Univ of Turin/Osped Molinette, Turin, Italy, 15Catholic University School of Medicine, Rome, Italy
In acromegaly, various factors may affect dosing of pegvisomant (PEGV). In patients with active disease we investigated which factors may influence the final dose of pegvisomant in a long-term study. Data from 128 subjects (72 F) evaluated in a retrospective cross-sectional study in 7 italian hospitals were collected. At study entry, 82% had undergone neurosurgery, 24% radioterapy and 91% was treated with somatostatin analogs (SSA). PEGV was added to SSA in 42% of patients. Patients initially received 10 mg/d and PEGV dose was adjusted by 5 mg every 8 week until serum IGF-I was normalized. The mean follow-up was 37.6+/-22.8 months. At baseline and after treatment, no differences in IGF-I levels were found according to sex and previous radiotherapy. At the end of follow-up, no differences were found in IGF-I levels and PEGV final dose between patients treated with PEGV alone or in combination with SSA. A stepwise multiple linear regression analysis showed a strong direct correlation between BMI, duration of PEGV therapy and final dose of PEGV required, regardless the treatment regimen (PEGV alone or in combination). In conclusion, BMI and duration of PEGV treatment influence the dose of PEGV required to normalize serum IGF-I in patients with active acromegaly during long-term PEGV therapy.

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(1) Filopanti M, et al.  Growth hormone receptor variants and response to pegvisomant in monotherapy or in combination withsomatostatin analogs in acromegalic patients: a multicenter study. J ClinEndocrinol Metab. 2012 Feb;97(2):E165-72. (2) Bernabeu I et al. The exon 3-deleted growth hormone receptor isassociated with better response to pegvisomant therapy in acromegaly. J ClinEndocrinol Metab. 2010 Jan;95(1):222-9. (3) Marazuela M et al. Long-term treatment of acromegalic patients resistantto somatostatin analogues with the GH receptor antagonist pegvisomant: its efficacy in relation to gender and previous radiotherapy. Eur J Endocrinol. 2009 Apr;160(4):535-42. (4) Bianchi A et al. Growth hormone receptor polymorphism and the effects of pegvisomant in acromegaly. Pituitary. 2009;12(3):196-9. (5) Parkinson C et al. Gender, body weight, diseaseactivity, and previous radiotherapy influence the response to pegvisomant. J ClinEndocrinol Metab. 2007 Jan;92(1):190-5.

Nothing to Disclose: AB, PM, SG, GA, MR, MRA, TP, AG, MCZ, SC, MB, NS, AG, EGGMG, AP, LD

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm