Background: Adherence to tyrosine kinase inhibitors (TKIs) is critical to maximize clinical effectiveness of drugs in patients with chronic myeloid leukemia (CML). However, adverse events (AEs) are one of the most frequent causes for non-adherence to TKI therapy. Aims: We herein report patients’ and physicians’ perception of using a newly developed online tool for patient-reported AEs monitoring in newly diagnosed CML patients in real-life practice. We also report health-related quality of life (HRQoL) and fatigue of patients up to six months. Methods: An online platform (EMPATHY) for systematic monitoring of patient-reported AEs (including a set 22 items mainly derived from the PRO-CTCAE Item Library) was developed for the purpose of this study. Newly diagnosed CML patients within 4 weeks of first line TKI therapy were eligible. At the time of a clinical visit (after having signed informed consent), and just before the consultation with the physician, patients were provided a tablet PC to self-rate (touchscreen) their symptoms. The local clinical research staff instructed patients on study procedures and on how to complete self- reported AEs via tablet. Patient-reported AEs were displayed graphically and available, in real time, to physicians’ PC during the clinical consultation. At 3- and 6-months both patients and physicians completed a Survey assessing acceptability, satisfaction and clinical utility of using this platform. At these time points, patient-reported HRQoL and fatigue were also assessed with the FACT-G and PROMIS-Fatigue questionnaires (via paper copies), respectively. Trajectories over time were estimated using a linear mixed model for repeated measures. Results: Ninety-four newly diagnosed CML patients were enrolled between July 2020 and August 2021 in 15 centers across US and Italy. There were 43% of patients treated with imatinib and 31%, 24% and 2%, treated with nilotinib, dasatinib and bosutinib, respectively. Median age of patients was 57 years (range, 19-82 years) and 55% were male. Sokal-risk was low in 42% of patients and 34% had at least one comorbidity. The majority of them (73%) used internet on a regular basis. The platform was generally well received by patients, for example, 99% (77/78) and 94% (73/78) of them agreeing or strongly agreeing (at 3 months) that it was easy to use and improved quality of communication with their physician, respectively. Of the 21 physicians (median age of 42 years) involved, nearly all (20/21; 95%) agreed that it was a valuable tool for improving accuracy of symptomatic AE of their patients. Similar high percentages were observed at 6 months. Compliance with patient-reported HRQoL and fatigue assessments was 99%, 93% and 93% at baseline, 3 and 6 months, respectively. No statistically significant differences were observed for the FACT-G and the PROMIS-Fatigue scores over time in the overall population. Summary/Conclusion: Current data suggest that the EMPATHY platform is well accepted by patients and physicians and its use may contribute to enhance physicians’ ability to better understand symptom burden of their patients.