BACKGROUND: We previously reported on the efficacy, safety, and quality of life (QoL) 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 IGF1 concentrations (n=63) or to increase the 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 the 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 present 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 and 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.

acromegaly, adult, aged, angiopeptin, article, cyclopeptide, diabetes mellitus, drug antagonism, drug combination, drug derivative, electrocardiography, female, follow up, growth hormone receptor, human, human growth hormone, liver function test, male, middle aged, octreotide, pathophysiology, pegvisomant, somatostatin,
European Journal of Endocrinology
Erasmus MC: University Medical Center Rotterdam

Neggers, S.J.C.M.M, de Herder, W.W, Janssen, J.A.M.J.L, Feelders, R.A, & van der Lely, A-J. (2009). Combined treatment for acromegaly with long-acting somatostatin analogs and pegvisomant: long-term safety for up to 4.5 years (median 2.2 years) of follow-up in 86 patients.. European Journal of Endocrinology (Vol. 160, pp. 529–533). doi:10.1530/EJE-08-0843