8404 Use of the Acromegaly Symptom Diary (ASD) in a Phase 3, Placebo-Controlled Study of Once-Daily, Oral Paltusotine in Patients With Acromegaly Switched From Injected Octreotide or Lanreotide

Abstract Disclosure: M.R. Gadelha: Consulting Fee; Self; Crinetics, Ipsen, Novo Nordisk, and Recordati. Research Investigator; Self; Crinetics and Recordati. Speaker; Self; Ipsen, Novo Nordisk, and Recordati. A. Casagrande: Employee; Self; Crinetics Pharmaceuticals. Stock Owner; Self; Crinetics Pharmaceuticals. C.J. Strasburger: Consulting Fee; Self; Amolyt Pharma, Consilient Health, Novo Nordisk, Recordati, and Sandoz-Hexal. Research Investigator; Self; Crinetics. M. Bidlingmaier: Consulting Fee; Self; Crinetics, Ionis, Novo Nordisk, Pfizer, Roche, and Sandoz. Research Investigator; Self; Amolyt, Camurus, Chiasma, Crinetics, IDS, Ionis, Lumos, and OPKO. Speaker; Self; Euroimmun, Novo Nordisk, and Pfizer. P.J. Snyder: Research Investigator; Self; Crinetics. M.A. Guitelman: Consulting Fee; Self; Recordati, Sanofi Aventis, and Varifarma. Research Investigator; Self; Crinetics. Speaker; Self; Recordati, Sanofi Aventis, and Varifarma. C.L. Boguszewski: Consulting Fee; Self; Ipsen, Novo Nordisk, and Recordati. Research Investigator; Self; Crinetics. Speaker; Self; Ipsen, Novo Nordisk, and Recordati. M. Buchfelder: Research Investigator; Self; Crinetics. I. Shimon: Consulting Fee; Self; Medison and Pfizer. Research Investigator; Self; Crinetics and Debiopharm. Speaker; Self; Medison and Pfizer. G. Raverot: Consulting Fee; Self; Amolyt, Crinetics, Ipsen, Novo Nordisk, Pfizer, and Recordati. Research Investigator; Self; Crinetics. Speaker; Self; Ipsen, Pfizer, and Recordati. M. Toth: Consulting Fee; Self; Ipsen, Lilly, Novartis, and Recordati. Research Investigator; Self; Crinetics. Speaker; Self; Ipsen, Lilly, Novartis, and Recordati. E. Mezosi: Research Investigator; Self; Crinetics. M. Doknic: Advisory Board Member; Self; Pfizer in CEE. Research Investigator; Self; Crinetics. X. Fan: Employee; Self; Crinetics Pharmaceuticals. Stock Owner; Self; Crinetics Pharmaceuticals. D. Clemmons: Consulting Fee; Self; Crinetics. M. Keeley: Employee; Self; Crinetics Pharmaceuticals. Stock Owner; Self; Crinetics Pharmaceuticals. P.J. Trainer: Employee; Self; Crinetics Pharmaceuticals. Stock Owner; Self; Crinetics Pharmaceuticals. R. Struthers: Employee; Self; Crinetics Pharmaceuticals. Stock Owner; Self; Crinetics Pharmaceuticals. A. Krasner: Employee; Self; Crinetics Pharmaceuticals. Stock Owner; Self; Crinetics Pharmaceuticals. B.M. Biller: Consulting Fee; Self; Amryt, Camurus, Crinetics, and Recordati. Research Investigator; Self; Crinetics and Ionis. Paltusotine is a once-daily, selective, non-peptide, SST2 receptor agonist in development as an oral treatment for patients with acromegaly or carcinoid syndrome. The Acromegaly Symptom Diary (ASD) is a novel patient-reported outcome tool developed in accordance with US FDA guidance to assess disease-related symptom burden. The ASD consists of 7 core items (headache, joint pain, sweating, fatigue, leg weakness, swelling, numbness/tingling, score range: 0-70; higher scores indicate greater symptom burden) plus 2 additional items (sleep difficulty, memory difficulty) and is completed daily. We previously reported the topline results of PATHFNDR-1 (NCT04837040), a phase 3 trial evaluating the efficacy and safety of paltusotine in adults with acromegaly who were previously controlled (IGF-I ≤1.0 ×ULN) on stable (≥12 weeks) injected octreotide or lanreotide. Patients were randomly allocated to once-daily paltusotine 40 mg or placebo for 36 weeks, with uptitration to 60 mg/day permitted through week 24. IGF-I and GH levels (IDS-iSYS) and pituitary tumor volume (MRI) were measured centrally. Fifty-eight patients (paltusotine, n=30; placebo, n=28) were enrolled: mean (±SD) age 54.9±13.7 years; 55.2% female; prior treatment octreotide LAR (n=34) or lanreotide depot (n=24). The primary endpoint (proportion of patients maintaining IGF-I ≤1.0 ×ULN [mean of weeks 34 and 36]) was met by significantly more patients on paltusotine (83.3%) versus placebo (3.6%; odds ratio: 126.53; 95% CI: 13.73, >999.99; P<0.0001). All secondary endpoints were met: mean (±SE) change in IGF-I of 0.04±0.09 ×ULN versus 0.83±0.1 ×ULN (P<0.0001); and GH maintained at <1.0 ng/mL in 87.0% versus 27.8% of patients (odds ratio: 16.61; 95% CI: 2.86, 181.36; P<0.001). The most common adverse events (AEs) were typical of the somatostatin receptor ligand (SRL) class or acromegaly symptoms. There were no severe or serious AEs in the paltusotine group. One patient in the placebo group discontinued study participation (patient decision). There were no clinically significant changes in pituitary tumor volume. The mean completion rate of the daily ASD questionnaire was 79.1%. At the end of randomized treatment, the ASD total score was significantly increased from baseline (indicating worsening) in the placebo group compared with the paltusotine group, meeting the secondary endpoint (-0.6±1.5 versus 4.6±1.6; P=0.02). For individual ASD symptoms, mean scores were consistently indicative of improvement with paltusotine compared to placebo; the between-group difference was statistically significant for joint pain (P<0.05), numbness/tingling (P<0.01), and the “most bothersome” symptom (P<0.05). In conclusion, once-daily oral paltusotine maintained symptom control in concert with biochemical values in well-controlled patients switched from injected SRLs and was well tolerated. Support: Crinetics Pharmaceuticals Presentation: 6/3/2024