The study focuses on adults who have Chronic rhinosinusitis with nasal polyps, a condition where the lining of the nose and sinuses stays inflamed for a long time and small growths called polyps develop, making breathing difficult and causing a runny nose or loss of smell. Participants will receive either the investigational medicine itepekimab, given as a subcutaneous injection (a shot under the skin), or a matched placebo that looks the same but does not contain the active drug.
The main goal is to assess the long‑term safety and tolerability of the medicine, meaning researchers will watch for any side effects or problems over an extended period. After the initial treatment period, participants will continue to attend regular visits where doctors will ask about health changes, perform a simple nasal examination, and may take a small blood sample to check drug levels. The study also records whether participants need additional treatments such as a short course of a systemic corticosteroid (a pill that reduces inflammation throughout the body) or sinus surgery.
Austria 
Belgium 
Czechia 
Denmark 
Finland 
France 
Germany 
Hungary 
Italy 
Poland 
Portugal 
Romania 
Spain 
Sweden 
The Netherlands