Time trends for drug specific adverse events in patients on sunitinib; implications for remote monitoring

Introduction: Sunitinib is a multi-targeted receptor tyrosine kinase inhibitor used to treat metastatic renal cell carcinoma (mRCC). Patients on sunitinib do require regular in-person appointments to monitor for adverse events (AEs). Given the Covid-19 pandemic, regular in-person visits expose patients to an increased risk of infection in addition to potentially preventable travel costs. This study investigated the feasibility of implementing a remote monitoring strategy for patients being treated with sunitinib for mRCC by examining the time trends of AEs. Materials and methods: In this retrospective chart review of patients with a diagnosis of mRCC, 167 patients received sunitinib during their treatment. The time between initiation of treatment and the first AE was recorded. The AEs were categorized according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5. Survival analysis was used to calculate the time-to-AE. Results: Of the 167 patients identified, 145 experienced an AE (86.8%). Hypertension was the most common AE with 80% of AEs were <= Grade 2. Incidence of AE dropped by 91% after 3 months follow up and a further 36% after 6 months. The cumulative incidence of AEs were 87.8%, 94.6% and 98.0%, at 3, 6 and 9 months respectively. The severity of AEs observed were 39.3%, 38.6%, 20.7%, 1.4%,0% of Grade 1-5 events respectively. A trend of grade migration to less severe grades was also shown over time, with percentage of Grade >= 3 toxicity dropping from 22% between 0-3 months to 14% beyond 6 months follow up. Conclusions: The role of remote monitoring for mRCC patients on sunitinib remains relevant now with new waves of the Covid-19 pandemic, triggered by novel variants. The majority of AEs observed were of low severity <= Grade 2, with a trend of reduced AE frequency and severity most prevalent beyond 3 months of follow up. This data appears to support the implementation of a remote monitoring strategy 3 months after initiation of treatment.