Pegvisomant in acromegaly: a multicenter real-life study in Argentina

Abstract

Objective: To describe the long term safety and efficacy of pegvisomant (PEGV), and the predictors of treatment response in patients with acromegaly in the real life setting. Subjects and methods: We retrospectively reviewed the clinical, hormonal and radiological data of acromegalic patients treated with PEGV in 17 Argentine centers. Results: Seventy-five patients (age range 22-77, 51 females) with acromegaly have been treated with PEGV for up to 118 months (median 27 months). Before PEGV, 97.3% of patients had been treated with medical therapy, surgery and/or radiotherapy, two patients had no previous treatment. At that time, all patients had an IGF-1 above the upper normal limit (ULN) (mean 2.4 x ULN ± 0.98, range 1.25-7). At diagnosis of acromegaly 84% presented macroadenomas, prior to PEGV only 23,5% of patients remained with tumor remnant > 1 cm, the remaining showed normal or less than 1 cm images. Disease control (IGF-1 ≤ 1.2 x ULN) was achieved in 62.9% of patients with a mean dose of 11.8 mg/day. Thirty-four patients (45%) received PEGV monotherapy, while 41 (55%) received combined therapy with either somatostatin analogues and/or cabergoline. Adverse events related to PEGV were: local injection site reaction in 5.3%, elevated liver enzymes in 9.3%, and tumor size growth in 9.8%. Pre-PEGV IGF-I level was the only predictor of treatment response: 2.1 x ULN vs 2.8 x ULN in controlled and uncontrolled patients respectively (p < 0.001). Conclusion: this long term experience indicates PEGV treatment was highly effective and safe in our series of Argentine patients with acromegaly refractory to standard therapies. Arch Endocrinol Metab.

A Pituitary Society update to acromegaly management guidelines

“…Overall, IGF-I control was observed in 71.7% of patients on pegvisomant monotherapy, with tumor growth noted in 7.3% and transaminase elevation in 3.0%. Real-word experiences independent of ACROSTUDY also mirrored these results, despite some country-specific differences in how pegvisomant is used in monotherapy vs combination therapy regimens [78][79][80]°I n 1,762 patients in ACROSTUDY, 29% of whom had DM at baseline (HbA1c ≥ 6.5%, FBG > 200 g/dL, or use of antidiabetic medication) [81], cross-sectional analysis at 4 years of follow-up showed that FBG and HbA1c remained stable in patients without DM, but prevalence of impaired glucose tolerance decreased from 11 to 8% at year 1 and 6.4% at year 4. Longitudinal analysis showed 53% of patients with DM and elevated IGF-I at baseline achieved IGF-I normalization by year 4, but decrease in IGF-I and glycemic change were not correlated.…”

Pegvisomant in Acromegaly and Gigantism

“…In the Brazilian study, tumour enlargement was reported in 6.5% of cases (n = 5). In the Argentinian study, 4 of 50 patients (8%) showed an increase in tumour size with pegvisomant ( Table 1) [33]. In the meta-analysis of five studies with pegvisomant in monotherapy, the overall tumour growth rate was 7.2% (4.8-10.7%; 95% CI; I 2 = 0%) [15].…”

“…In the Brazilian and Argentinian cohort, elevation of liver enzymes was reported in 9% of cases and was responsible for pegvisomant discontinuation in 1 and 5 patients, respectively ( Table 1) [14,33].…”

Pegvisomant for acromegaly: does it always works?

“…T wo studies published in this present issue of the Archives of Endocrinology and Metabolism, by Natalia Garcia Basavilbaso (1) and coworkers, as well as the one by Cesar Boguszewski and coworkers (2), describe the treatment response in real-life of pegvisomant (PEGV) therapy in acromegaly patients, including aspects of safety and efficacy.…”

“…Serum IGF-I levels decreased to normal ranges in "only" 63% of patients after a median treatment duration of 27 months, with a daily mean dose of about 12 mg (2). In the Brazilian report, PEGV was used as monotherapy in 11% of the cases, while normal IGF-I levels were obtained in about 75% of patients (1). Why more patients cannot be controlled in the real-life setting of center of excellence?…”