OBJECTIVE: Examine, in a real-world setting, whether strict normalization of modestly elevated insulin-like growth factor 1 (IGF1) results in clinical and health-related quality of life benefits in patients with acromegaly using an open-label, non-randomized, 6-month prospective interventional study. METHODS: In patients with acromegaly and modest IGF1 elevation, strict IGF1 control was achieved by addition or dose escalation of pegvisomant. Clinical and biochemical parameters were assessed at baseline, 1 and 3 months for pegvisomant dose titration, and at 6 months. The Patient-Assessed Acromegaly Symptom Questionnaire (PASQ), the Acromegaly Quality of Life questionnaire (AcroQoL) and the Acromegaly Disease Activity Tool (ACRODAT RESULTS: Ten patients (8 males) with mean age of 50.7 years participated in the study. All patients had a macroadenoma and nine had prior transsphenoidal surgeries. At time of screening, six patients were on a somatostatin analog, two on pegvisomant, and two on pegvisomant and a somatostatin analog. After six months of dose escalation or the addition of pegvisomant, IGF1 decreased from 1.22 ± 0.14 to 0.87 ± 0.20 times the upper limit of normal (p=0.001). PASQ score decreased by 3.5 (p=0.02) and the ACRODAT CONCLUSIONS: In this pilot study, stricter control of modest IGF1 elevations led to symptomatic improvement as measured by the PASQ score. These findings prompt larger prospective trials.