5783 REAL-LIFE USE OF TOLVAPTAN IN ADPKD: A RETROSPECTIVE ANALYSIS OF A LARGE CANADIAN COHORT

Abstract Background and Aims Tolvaptan is the first disease-modifier therapy proven to slow eGFR decline in high-risk patients with ADPKD. However, barriers to its use in real-life settings have not been examined. Method Single-center, retrospective study of 523 current or new patients with ADPKD followed at the Center for Innovative Management of PKD in Toronto, Ontario between January 1, 2016 to December 30, 2018. All patients had clinical assessment and total kidney volume measurements; those deemed to be at high risk based on their Mayo Clinic Imaging Class (MCIC) 1C, 1D, or 1E, were offered tolvaptan with their preference (yes or no) and reasons for their choices recorded. Results Overall, 315/523 (60.2%) patients had MCIC 1C-1E; however, only 96 (30%) of them were treated with tolvaptan at the last follow-up. Among these high-risk patients, those treated with tolvaptan were more likely to have a higher eGFR (61 ±27 vs. 82 ±26 ml/min/1.73 m2), CKD stages 1–2 (41% vs. 79%), and MCIC 1D-1E (69% vs. 37%). The most common reasons provided for not taking tolvaptan were lifestyle preference related to the aquaretic effect (51%), older age ≥60 (12%), and pregnancy or family planning (6%). Conclusion In this real-world experience, at least 60% of patients with ADPKD considered to be at high risk for progression to ESKD by imaging were not treated with tolvaptan; most of them had earlier stages of CKD with well-preserved eGFR. The most common reason for their refusal to consider tolvaptan is a concern for intolerability of the aquaretic side-effect; strategies to mitigate this side-effect may help to reduce the barrier to tolvaptan therapy. Figure 1: Reasons for not using tolvaptan among ADPKD patients with Mayo Clinic Imaging Classification 1C,1D,1E (n = 219) from the cohort followed primarily or co-managed with their primary nephrologists by the Center for Innovative Management of Polycystic Kidney Disease. aUnspecified: No reason provided in the response. bConsidering: Patients who are considering tolvaptan but remain undecided. cFamily planning: Planning pregnant or contemplating pregnancy. dAdvanced age: Age ≥60 with perceived reduced benefit of tolvaptan usage. eLifestyle: Patients who had refused tolvaptan due to being unable to handle the possible aquaretic effect of the medication due to either their occupation or social circumstances. Table 1: Clinical Characteristics of High-Risk Patients with Mayo Clinic Imaging Class 1C, 1D, or 1E on tolvaptan vs.