Understanding the late immune checkpoint inhibitor (ICI) symptom experience using an electronic patient reported outcomes (ePRO) app-based platform: The immunowave study.

e24067 Background: Chronic toxicities of ICI cancer therapy remain largely uncharacterized. With increasing use of ICIs in early cancer stages, the number of cancer patients exposed to ICI therapy will continue to increase. We undertook a smartphone app-based ePRO pilot study to examine symptom experience of patients with prior or ongoing (≥ 6 months) treatment with ICIs. Methods: Eligible patients had a history of advanced skin cancer or kidney cancer treated with ICI therapy (adjuvant or metastatic setting) with ongoing, clinician-assessed cancer control. Patients may have completed a course of ICI therapy or continued on therapy if ≥ 6 months had passed since initiation. We conducted a single-center, observational, prospective cohort study where participants completed weekly ePRO assessments measuring 11 PRO-CTCAE symptoms over 12 weeks. We assessed the feasibility of this app-based ePRO monitoring strategy (defined as the fraction of weekly assessments completed) and described the prevalence and severity of symptoms in this population. Results: Forty-seven patients (77% melanoma, 15% renal cell carcinoma, 8% non-melanoma skin cancer) consented to the study. At enrollment, 70% were on active therapy while 30% had completed therapy. 38% received adjuvant therapy and 62% were treated in a metastatic setting. The majority (N = 43, 91%) completed ≥ 1 weekly ePRO assessment (median 8, IQR 5.5-10). These 43 patients were included in the analysis. 61% (317/516) of the scheduled ePRO symptom assessments were completed. The prevalence, severity, and persistence of symptoms are noted in the Table. Fatigue and joint pain were most commonly reported (85% and 66% of assessments, respectively) and most commonly Grade ≥ 3 symptoms (23%, 20%). More than half of the patients reported persistent (present ≥ 50% of a patient’s assessments completed) symptoms of fatigue, joint pain, muscle pain, itchiness, rash, depression, anxiety, and numbness. Conclusions: Weekly app-based ePRO monitoring allowed for longitudinal assessment of symptoms with reasonable completion rates. Patients reported frequent, persistent, and sometimes severe symptoms, most notably fatigue, mental health symptoms, and musculoskeletal symptoms. This study suggests that patients during and after ICI therapy may experience high symptom burden, warranting further study in a larger population with longer study duration to identify candidate symptoms for interventions. [Table: see text]