Usability and Usefulness of a Symptom Management Coaching System for Patients With Cancer Treated With Immune Checkpoint Inhibitors: Comparative Mixed Methods Study - Glaser, Savannah Lucia Caterina; Fraterman, Itske; van Brummelen, Noah; Tibollo, Valentina; Del Campo, Laura Maria; Mallo, Henk; Wilgenhof, Sofie; Wilk, Szymon; Gisko, Vitali; Khadakou, Vadzim; Cornet, Ronald; Ottaviano, Manuel; et al. (Jmir Formative Research, 2025)