Usability and Usefulness of a Symptom Management Coaching System for Patients With Cancer Treated With Immune Checkpoint Inhibitors: Comparative Mixed Methods Study - Savannah Lucia Caterina Glaser; Itske Fraterman; Noah van Brummelen; Valentina Tibollo; Laura Maria Del Campo; Henk Mallo; Sofie Wilgenhof; Szymon Wilk; Vitali Gisko; Vadzim Khadakou; Ronald Cornet; Manuel Ottaviano; et al. (JMIR Formative Research)