8008 Insulin-like Growth Factor-1 (IGF-1) Level Fluctuations and Patient Reported Outcomes (PROMS) During Treatment with Long-acting Somatostatin Receptor Ligands (SRLs) for Acromegaly: a Prospective Study

Abstract Disclosure: I. Remba-Shapiro: None. J.R. Schweizer: None. K.J. Liebert: Consulting Fee; Self; Crinetics, Recordati Rare Diseases, Novo Nordisk. K. Schilbach: None. M. Adams: Consulting Fee; Self; Chiesi. N.A. Tritos: None. M. Bidlingmaier: Consulting Fee; Self; Ipsen, Ionis Pharmaceuticals Inc., Novartis Pharmaceuticals, Novo Nordisk, Pfizer, Inc., Roche Pharmaceuticals. L.B. Nachtigall: Consulting Fee; Self; Crinetics. Grant Recipient; Self; Amryt, Recordati Rare Diseases. Background: SRLs are the most used medical therapy for acromegaly. Some patients report symptoms of acromegaly towards the end of the injection cycle even when IGF-1 levels are controlled. IGF-1 fluctuations within an injection cycle have been observed. In this study we investigated the variability of biochemical markers and PROMS in patients receiving long-acting SRLs. Methods: Subjects with acromegaly controlled with monthly lanreotide depot or octreotide LAR were recruited. Blood samples at 1 and 4 weeks after SLR injection were collected in 2 consecutive cycles. Clinical characteristics were evaluated. Quality of life (QoL) surveys included: Acromegaly Quality of Life Questionnaire (AcroQoL) (higher scores = better QoL) and Patient Assessed Acromegaly Symptom Questionnaire (PASQ) (higher scores = worse QoL). Week 1 vs. week 4 values were compared. Quest Diagnostics LC-MS assay was used to measure IGF-1. Coefficient of variation (CV = (IGF-1 SD)/(IGF-1 mean)%) of IGF-1 was calculated. Values ≤5% were interpreted as being a consequence of assay variability. Variables are presented as mean (SD) and compared using t-test; p