MO027: Clinical efficacy of treatment with tolvaptan in patients with autosomal dominant polycystic kidney disease

Abstract

Abstract BACKGROUND AND AIMS Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease. The only treatment approved today to slow its progression is tolvaptan (vasopressin antagonist). However, there is no clinical efficacy parameter for follow-up during treatment. To assess the clinical efficacy of treatment based on analytical (Fg) and radiological parameters: total kidney volume adjusted to height (TKV h). METHOD Retrospective observational study was undertaken of patients with ADPKD on treatment with tolvaptan after its approval in Spain in 2017. RESULTS Of the 182 ADPKD, 18% (n = 33) started treatment. The mean follow-up time of patients was 39.85 ± 10.04 months. Of the patients included; 60.6% (n = 20) were male, age 47.64 ± 8.64 years, a baseline glomerular filtration rate of 65.24 ± 20.14 mL/min and a height-adjusted total baseline renal volume of 1137.45 ± 667.58 mL. Baseline Mayo Clinic classification: 1C (72.7%), 1D (15.2%) and 1E (12.1%). Baseline CKD stages were as follows: 1: 15.2% (n = 5), 2:48.5% (n = 16), 3a:18.2% (n = 6), a 12.1% (n = 4) and 6.1% stage 4 (n = 2). The variation of Fg (mL/min), with respect to baseline was as follows: 1, 3, 6, 12, 24 and 36 months: (−4.26 ± 5.65; −3.54 ± 4.52; −1.68 ± 5.71, −10.89 ± 21.65, −10.54 ± 12.64, −8.08 ± 7.5). Fg decreased at months 1, 3, 6, 12, 12, 24 and 36 by 72.7%, 67.7%, 44.8%, 70.8%, 70.8%, 85% and 85.7%, the latter follow-up period being reached in 14 patients of the sample studied. Despite the decrease in Fg, 100% of the patients at 36 months had a higher Fg than expected according to the Mayo Clinic Fg prediction model, in accordance with their TKV at baseline. A mean decrease in TKVh was observed in annual control periods, the mean being as follows: −80.8 ± 290, −14.7 ± 187 and −82.8 ± 415.8 mL. In 100% of the patients with control at the third year (17 patients of the total sample), the percentage increase in TKV was lower than expected according to the Mayo Clinic model. CONCLUSION Although there is no efficacy parameter in the follow-up of treatment with tolvaptan in patients with ADPKD, our study shows an improvement in the expected value of both Fg and TKV; therefore, it could be considered an effective drug.