Endocrine Abstracts

Background: We previously reported on the efficacy, safety and Quality of Life of long-acting somatostatin analogs (SSA) and (twice) weekly pegvisomant (PEG-V) in acromegaly and improvement after the addition of PEG-V to long-acting SSA.

Objective: To assess the long term safety in a larger group of acromegalic patients over a larger period of time; 29.2 (1.2–57.4) months (mean (range)).

Design: Pegvisomant was added to SSA monotherapy in 86 subjects (37 females), to normalize serum IGF-I concentrations (n=63) or to increase the Quality of life (QoL). The median dosage was 60.0 (20–200) mg weekly.

Results: After a mean treatment period of 29.2 months, 23 patients showed dose independent PEG-V related transient liver enzyme elevations (TLEE). TLEE occurred only once during continuation of combination therapy, but discontinuation and re-challenge induced a second episode of TLEE. Ten of these patients with TLEE also suffered from diabetes mellitus (DM). In our current series DM had a 2.28 (odds ratio)(CI 1.16–9.22; P=0.03) higher risk for developing TLEE. During the combined therapy, a clinical significant decrease in tumor size by more than 20% was observed in 14 patients. Two of these patients were previously treated by pituitary surgery, 1 with additional radiotherapy, all other patients received primary medical treatment.

Conclusion: Long-term combined treatment with SSA and (twice) weekly PEG-V up to more than 4 years seems to be safe. Patients with both acromegaly and DM have a 2.28 higher risk of developing TLEE. Clinical significant tumor shrinkage was observed in 14 patients during combined treatment.