Safety and efficacy of once-daily oral paltusotine in acromegaly: ACROBAT Advance open-label extension up to 4 years

CONTEXT: Paltusotine is the first non-peptide selective somatostatin 2 receptor agonist approved as once-daily oral treatment for acromegaly. OBJECTIVE: To evaluate long-term treatment with paltusotine in patients with acromegaly previously on an injected somatostatin receptor ligand (SRL)-based regimen. METHODS: ACROBAT Advance is an ongoing open-label extension (OLE) study. Interim results (up to year 4) are reported. Enrolled patients had completed a phase 2 parent study: ACROBAT Edge (baseline insulin-like growth factor I [IGF-I] > 1× upper limit of normal [ULN] on injected octreotide or lanreotide ± cabergoline, or baseline IGF-I ≤ 1×ULN with combination therapy or pasireotide) or ACROBAT Evolve (baseline IGF-I ≤ 1×ULN on injected SRL monotherapy). Maximum paltusotine dose was initially 40 mg, then 60 mg, when a tablet formulation became available in year 3. Adjunctive treatment with cabergoline or pegvisomant was allowed as clinically indicated. RESULTS: Forty-three patients (88% of eligible patients from ACROBAT Edge and Evolve) enrolled in the OLE. Median (interquartile range) IGF-I levels were: 1.15×ULN (0.84, 1.46) at parent study baseline (n = 43), 1.17×ULN (0.98, 1.54) at Advance week 3 (n = 43), and 1.01×ULN (0.83, 1.13) at Advance week 207 (n = 20). Growth hormone levels, acromegaly symptoms, and pituitary tumor size remained stable. Paltusotine was well tolerated, with no unexpected safety findings observed. As of this analysis, 8 (18.6%) patients had discontinued from the study, including 2 (4.7%) due to adverse events. CONCLUSIONS: Once-daily oral paltusotine treatment was well tolerated and resulted in long-term disease control, including biochemical, symptom, and pituitary tumor stability, for up to 4 years.