•Background: ABPA and asthma associated with cystic fibrosis impact the CF course with a more rapid decline in lung function.~Corticosteroid therapy can be harmful and must be avoid in CF to prevent diabetes, osteoporomalacia or mycobacterium infections.~Monoclonal antibodies have the marketing authorization for severe uncontrolled asthma and, up to now, some CF patients with ABPA or severe asthma and high plasma IgE levels benefit from omalizumab.~Anti-Il5 agents are available since February 2019 and have demonstrated their efficacy in severe and hypereosinophilic asthma control (plasma eos.>300mmol/L).~Some patients with CF who have severe asthma or ABPA are still poorly controlled despite Omalizumab with other treatments (steroids and/or azoles). Some of them have persistent hypereosinophilia suggesting a possibility to treat with antiIL5 antibodies.~About 5% of patients have biotherapy treatment criteria, some have already received it, others are elective to such treatment and will receive in the future.~Methods:~Our project is to describe retrospectively and prospectively the clinical history of CF patients eligible for biotherapy in French CF centers.~Main objective: To describe the clinical and paraclinical course of CF patients before and after treatment with anti-IL5 and other biotherapies since 2019.~Secondary objective: To describe any adverse events potentially related to the biotherapies.
Our project is to describe retrospectively and prospectively CF patients treated with biotherapy in French CF centers.~Main objective: To describe the clinical and paraclinical course of CF patients before and after treatment with anti-IL5 and other biotherapies since 2019.~Secondary objective: To describe adverse events potentially related to the biotherapies.