Partial response to first generation SSA guides the choice and predict the outcome of second line therapy in acromegaly

• Published in: Endocrine Vol. 78; no. 2; pp. 343 - 353
• Main Authors: Chiloiro, Sabrina, Costa, Denise, Lauretta, Rosa, Mercuri, Valeria, Sbardella, Emilia, Samperi, Irene, Appetecchia, Marialuisa, Bianchi, Antonio, Giampietro, Antonella, Gargiulo, Patrizia, Isidori, Andrea M., Poggi, Maurizio, Pontecorvi, Alfredo, De Marinis, Laura
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2022; Springer Nature B.V
• Subjects: Acromegaly; Diabetes; Dosage; Endocrinology; Humanities and Social Sciences; Insulin-like growth factor I; Internal Medicine; Medicine; Medicine & Public Health; multidisciplinary; Original; Original Article; Patients; Science; Somatostatin; Tumors; GH; IGF-I; Pegvisomant; Growth hormone; Pasireotide; GH secreting pituitary adenoma
• ISSN: 1559-0100; 1355-008X; 1559-0100
• DOI: 10.1007/s12020-022-03158-w

Introduction Treatment of acromegaly resistant to first generation somatostatin analogues (first gen-SSA) is often difficult. We aimed to investigate the role of partial response and resistance to first gen-SSA in the choice of second line treatments and their outcomes. Patients and methods A retrospective and multicenter study was conducted on 100 SSA-resistant acromegaly patients and treated with Pasireotide Lar (Pasi-Lar), Peg-V in monotherapy (m-Peg-V) or in combination with first gen-SSA (c-Peg-V). Results Thirty-three patients (33%) were treated with m-Peg-V, 36 (36%) with c-Peg-V and 31 with Pasi-Lar (31%). According to logistic regression, m-Peg-V was chosen in older patients ( p  = 0.01) and with not-invasive adenomas ( p  = 0.009), c-Peg-V therapy in younger patients ( p  = 0.001), with invasive adenomas ( p  = 0.02), Pasi-Lar was in invasive adenomas ( p  = 0.01) and in patients partially responsive to first-gen SSA ( p  = 0.01). At the last follow-up, 68 patients (68%) reached the acromegaly control: 22 with m-Peg-V (32.4%), 23 with c-Peg-V (33.8%) and 23 with Pasi-Lar (33.8%). Patients non-responsive to c-Peg-V had higher IGF-I levels (median 3.2 x ULN, IQR: 1.6, p  < 0.001) and required higher Peg-V dosage (median 30 mg/daily IQR: 10, p  = 0.002) as compared to responsive patients (median IGF-I x ULN: 2.1 IQR: 1.4; median Peg-V dosage 20 mg/daily IQR: 10). All patients responsive to Pasi-Lar were partially responsive to first gen-SSAs ( p  = 0.02). Conclusion Our data showed that c-Peg-V and Pasi-Lar are chosen for the treatment of invasive tumors. The partial response to first gen-SSA seems to be the main determinant for the choice of Pasi-Lar and positively predicts the treatment outcome.