Carcinoid Syndrome

A Phase 3, randomized, double-blinded, placebo-controlled study to evaluate the efficacy and safety of paltusotine treatment vs placebo as well as the long-term safety of paltusotine in adults with carcinoid syndrome due to well-differentiated neuroendocrine tumors. The purpose of this study is to continue the evaluation of the safety, efficacy, and pharmacokinetics (PK) of paltusotine in participants with carcinoid syndrome.

Carcinoid tumors are neuroendocrine tumors (NETs), most commonly originating from the gastrointestinal tract, that may secrete bioactive substances such as serotonin. Persistent exposure to these mediators can lead to carcinoid syndrome and, in up to 50% of patients, carcinoid heart disease (CHD). CHD is characterized by fibrotic degeneration of cardiac valves, predominantly right-sided, resulting in progressive valvular dysfunction and a significant increase in mortality. The mechanisms underlying selective cardiac involvement and predictors of disease progression remain incompletely understood. In addition, optimal timing and selection of surgical versus transcatheter valve interventions, particularly in high-risk patients, require further clarification. This multicenter, retrospective observational registry aims to identify and characterize patients with carcinoid heart disease and at least moderate valvular involvement. CHD is defined by confirmed neuroendocrine tumor, echocardiographic evidence of ≥ moderate valvular disease with features of fibrosis, elevated NT-proBNP (\>260 ng/L), and histopathological confirmation when available. Approximately 100-120 consecutive patients will be enrolled over 12 months. Standardized data collection will include detailed echocardiographic assessment, demographic and clinical characteristics, cardiovascular risk factors, comorbidities, tumor features, oncological treatment history, and cardiac management strategies. The primary objective is to describe the clinical profile and management of patients with CHD in a real-world multicenter setting. Secondary objectives include identifying factors associated with advanced valvular dysfunction and evaluating eligibility and outcomes of transcatheter valve therapies. The registry is expected to improve risk stratification and support clinical decision-making in carcinoid heart disease.