Prediction of therapy response in acromegalic patients under pegvisomant therapy within the German ACROSTUDY cohort.

Abstract

This study aimed at investigating predicting factors for therapy response under growth hormone receptor antagonist therapy with a focus on subjective and patient-oriented measures. Observational, multicenter nested-cohort study including 271 selected patients with the diagnosis of acromegaly and a minimum of one-year follow-up period within the German ACROSTUDY cohort (total cohort: n=514). Outcome measures were the change of the biomarker IGF-1 (IGF-1 change and IGF-1 normalisation) between baseline and after 1year of pegvisomant therapy (12±6months). Main predictors were patient-assessed subjective measures according to the Patient-Assessed Acromegaly Symptom Questionnaire (PASQ) in conjugation with age, gender, BMI, max. dosage of pegvisomant at follow-up and IGF-1 before the start of pegvisomant therapy. The mean age of the study population was 51.2 (13.9) years and the mean BMI was 29.5 (5.1)kg/m(2). In adjusted analyses, none of the individual perceived health (PASQ) scores, but age, BMI and IGF-1 at baseline were predictive for an IGF-1 decrease after 1year of pegvisomant therapy and BMI and IGF-1, but equally none of the PASQ items, were predicting IGF-1 normalisation. Age, BMI and baseline IGF-1 but not subjective perceived health measures predict therapy response under second line medical therapy with pegvisomant.