Gansevoort, Ron T.

Abstract Background Pain is the highest prioritized patient-reported outcome in people with autosomal dominant polycystic kidney disease (ADPKD) but remains infrequently and inconsistently measured in clinical trials and poorly managed in clinical settings. A recently completed systematic review of pain in ADPKD identified 26 different outcome measures. None of these measures were considered appropriate as a core outcome measure due to the lack of patient-important dimensions, inadequate content, relatively long duration of completion time and limited evidence to support psychometric robustness. Methods We convened an international Standardized Outcomes in Nephrology–Polycystic Kidney Disease consensus workshop involving 21 patients/caregivers and 40 health professionals (clinicians, nurses, researchers, policy makers and industry representatives) from 18 countries to discuss the identification or development of a core outcome measure for pain. Results Four themes were identified highlighting fundamental issues for the measurement of pain in ADPKD: distressing and disrupting life participation; variability and ambiguity in defining pain; stigma, frustration and adaptation to pain; and ensuring validity and feasibility of pain measures. Conclusions Existing measures were found to be insufficient in capturing pain as a core outcome and there was consensus on the need for a new validated measure that is simple, succinct and addresses the impact of pain on life participation. This measure will facilitate the appropriate prioritization of pain in all trials and guide clinical decision making in people with ADPKD.

Significance Statement Patients with autosomal dominant polycystic kidney disease are treated with tolvaptan, a V2 receptor antagonist, to slow progression toward ESKD. In theory, tolvaptan could have both BP-increasing and BP-decreasing effects. To investigate the magnitude and time course of the effect of tolvaptan use on BP, the authors conducted a post hoc analysis of data from the TEMPO 3:4 trial, which randomized 1445 patients with autosomal dominant polycystic kidney disease to tolvaptan or placebo. Their analysis shows that directly after start of tolvaptan therapy, BP does not change, but in the long term, BP gradually becomes lower in patients with tolvaptan compared with placebo. This observation might be attributed to the beneficial effect of tolvaptan on disease progression, a sustained natriuretic effect, or both. Background The V2 receptor antagonist tolvaptan is prescribed to patients with autosomal dominant polycystic kidney disease to slow disease progression. Tolvaptan may alter BP via various acute and chronic effects. Methods To investigate the magnitude and time course of the effect of tolvaptan use on BP, we conducted a post hoc study of the TEMPO 3:4 trial, which included 1445 patients with autosomal dominant polycystic kidney disease randomized 2:1 to tolvaptan or placebo for 3 years. We evaluated systolic and diastolic BP, mean arterial pressure, hypertension status, and use and dosing of antihypertensive drugs over the course of the trial. Results At baseline, BP did not differ between study arms. After 3 weeks of tolvaptan use, mean body weight had decreased from 79.7 to 78.8 kg, and mean plasma sodium increased from 140.4 to 142.6 mmol/L (both P <0.001), suggesting a decrease in circulating volume. We observed none of these changes in the placebo arm. Nonetheless, BP remained similar in the study arms. After 3 years of treatment, however, mean systolic BP was significantly lower in participants receiving tolvaptan versus placebo (126 versus 129 mm Hg, respectively; P =0.002), as was mean diastolic BP (81.2 versus 82.6 mm Hg, respectively; P =0.01). These differences leveled off at follow-up 3 weeks after discontinuation of the study medication. Use of antihypertensive drugs remained similar in both study arms during the entire study. Conclusions Long-term treatment with tolvaptan gradually lowered BP compared with placebo, which may be attributed to a beneficial effect on disease progression, a continued natriuretic effect, or both. Clinical Trial registry name and registration number: TEMPO 3:4, NCT00428948

Background and objectives Tolvaptan slows kidney function decline in patients with autosomal dominant polycystic kidney disease (ADPKD) at risk of rapid progression. In the 3-year Tolvaptan Efficacy and Safety in Management of ADPKD and Its Outcomes (TEMPO) 3:4, 2-year extension to TEMPO 3:4 (TEMPO 4:4), and 1-year Replicating Evidence of Preserved Renal Function: An Investigation of Tolvaptan Safety and Efficacy in ADPKD (REPRISE) trials, aquaretic adverse events were common. Serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) elevations occurred in all three studies. Three patients met Hy Law criteria (ALT or AST more than three times and total bilirubin more than two times the upper limit of normal) for severe drug-induced liver injury (two in TEMPO 3:4 and one in TEMPO 4:4). In REPRISE, liver enzyme monitoring frequency was increased to monthly, with no Hy Law cases. A long-term, phase 3 safety study has further characterized tolvaptan safety. Design, setting, participants, & measurements Subjects who completed TEMPO 4:4, REPRISE, or other tolvaptan trials could enroll in this prospective, multinational, open-label safety study. Assessments included monthly liver enzyme testing during the first 18 months of tolvaptan exposure and every 3 months thereafter. Results Among 1803 subjects, median tolvaptan exposure during the extension was 651 days (interquartile range, 538–924), and cumulative exposure (extension and previous trials) was ≤11 years. Subjects entering from REPRISE placebo experienced more aquaretic adverse events compared with subjects from TEMPO 4:4 or REPRISE tolvaptan ( i.e ., patients with prior long-term tolvaptan exposure). Liver enzyme elevations also occurred more frequently in subjects from REPRISE placebo. Percentages experiencing ALT ≥3/≥5/ ≥10/≥20 times the upper limit of normal were 3.2%/2.1%/0.9%/0.7%, respectively, in subjects from REPRISE placebo and 0.6%–1.1%/0.0%–0.1%/0%/0%, respectively, in those from REPRISE tolvaptan and TEMPO 4:4. Percentages experiencing AST ≥3/ ≥5/≥10/≥20 times the upper limit of normal were 6.9%/3.8%/2.3%/0.8%, respectively, in subjects from REPRISE placebo and 0.9%–2.0%/0.0%–1.0%/0%/0%, respectively, in those from REPRISE tolvaptan and TEMPO 4:4. No Hy Law cases occurred. Conclusions No new safety signals emerged during this long-term extension. Monthly liver function testing for the first 18 months of treatment appeared to enable effective detection and management of transaminase elevations. Clinical Trial registry name and registration number: Open Label Extension of TEMPO 3:4, NCT02251275

Significance Statement Because renal function often remains stable in the early stages of autosomal dominant polycystic kidney disease (ADPKD), total kidney volume (TKV) is the most important biomarker of disease severity and progression. The authors developed and validated a fully automated method of simultaneously measuring TKV and total liver volume (TLV) as well as their growth rates from magnetic resonance images. Their findings indicate that the method’s performance is equivalent to the gold standard of manual tracing while requiring a fraction of the time and skill. This approach may address the unmet need for rapid and reliable assessment of TKV and TLV, allowing identification of patients with rapidly progressing ADPKD for emerging drug treatments and serving as a reliable alternative for assessment of disease progression in clinical trials. Background The formation and growth of cysts in kidneys, and often liver, in autosomal dominant polycystic kidney disease (ADPKD) cause progressive increases in total kidney volume (TKV) and liver volume (TLV). Laborious and time-consuming manual tracing of kidneys and liver is the current gold standard. We developed a fully automated segmentation method for TKV and TLV measurement that uses a deep learning network optimized to perform semantic segmentation of kidneys and liver. Methods We used 80% of a set of 440 abdominal magnetic resonance images (T2-weighted HASTE coronal sequences) from patients with ADPKD to train the network and the remaining 20% for validation. Both kidneys and liver were also segmented manually. To evaluate the method’s performance, we used an additional test set of images from 100 patients, 45 of whom were also involved in longitudinal analyses. Results TKV and TLV measured by the automated approach correlated highly with manually traced TKV and TLV (intraclass correlation coefficients, 0.998 and 0.996, respectively), with low bias and high precision (<0.1%±2.7% for TKV and −1.6%±3.1% for TLV); this was comparable with inter-reader variability of manual tracing (<0.1%±3.5% for TKV and −1.5%±4.8% for TLV). For longitudinal analysis, bias and precision were <0.1%±3.2% for TKV and 1.4%±2.9% for TLV growth. Conclusions These findings demonstrate a fully automated segmentation method that measures TKV, TLV, and changes in these parameters as accurately as manual tracing. This technique may facilitate future studies in which automated and reproducible TKV and TLV measurements are needed to assess disease severity, disease progression, and treatment response.

ABSTRACTAimPatients with autosomal dominant polycystic kidney disease (ADPKD) are at increased risk of premature mortality, morbidities and complications, which severely impair quality of life. However, patient‐centered outcomes are not consistently reported in trials in ADPKD, which can limit shared decision‐making. We aimed to identify outcomes important to patients and caregivers and the reasons for their priorities.MethodsNominal group technique was adopted involving patients with ADPKD and caregivers who were purposively selected from eight centres across Australia, France and the Republic of Korea. Participants identified, ranked and discussed outcomes for trials in ADPKD. We calculated an importance score (0–1) for each outcome and conducted thematic analyses.ResultsAcross 17 groups, 154 participants (121 patients, 33 caregivers) aged 19 to 78 (mean 54.5 years) identified 55 outcomes. The 10 highest ranked outcomes were: kidney function (importance score 0.36), end‐stage kidney disease (0.32), survival (0.21), cyst size/growth (0.20), cyst pain/bleeding (0.18), blood pressure (0.17), ability to work (0.16), cerebral aneurysm/stroke (0.14), mobility/physical function (0.12), and fatigue (0.12). Three themes were identified: threatening semblance of normality, inability to control and making sense of diverse risks.ConclusionFor patients with ADPKD and their caregivers, kidney function, delayed progression to end‐stage kidney disease and survival were the highest priorities, and were focused on achieving normality, and maintaining control over health and lifestyle. Implementing these patient‐important outcomes may improve the meaning and relevance of trials to inform clinical care in ADPKD.