Abstract Body (Do not enter title and authors here): Background: Galectin-3 (Gal-3) is a circulating biomarker of fibrosis, with higher levels having been associated with an increased risk of progression of kidney disease. Patients with type 2 diabetes mellitus (T2DM) are at increased risk for kidney disease with fibrosis.

Aims: To study the association of Gal-3 with chronic kidney disease progression, and the effect of the SGLT2-inhibitor dapagliflozin in pts with T2DM.

Methods: DECLARE-TIMI 58 was a randomized, placebo-controlled trial of dapagliflozin in pts with T2DM with or at high risk for atherosclerotic cardiovascular (CV) disease and creatinine clearance ≥60ml/min. In a nested biomarker substudy, Gal-3 was measured at baseline (Alinity, Abbott Diagnostics) in the TIMI Clinical Trials Laboratory (Boston, MA). The prespecified kidney-specific composite endpoint (Kidney-EP) was a sustained ≥40% decrease in eGFR to <60 mL/min, initiation of renal replacement therapy or confirmed sustained eGFR <15 mL/min, or adjudicated renal death. Cox models were adjusted for baseline eGFR, urine albumin-creatinine ratio (UACR), patient characteristics, CV risk factors, NTproBNP and hs-cTnT.

Results: Among 14,530 pts, median Gal-3 was 14.9 ng/mL [IQR, 11.9, 18.4]. Gal-3 was weakly associated with UACR (r = 0.098, p < 0.0001) and eGFR (r = -0.27, p<0.001) at baseline. Gal-3 was independently associated with the incidence of the Kidney-EP (adj-HR 1.15 [95% CI 1.03, 1.28] per 1-SD log(Gal-3), p = 0.013). Upon stratification by quartiles, there was a gradient of higher adjusted risk of the Kidney-EP with higher Gal-3 (Fig., A; p-trend <0.0001). There were 111 (1.5%) and 203 (2,8%) Kidney-EPs in the dapagliflozin and placebo groups, respectively. Dapagliflozin significantly and similarly reduced the relative risk of the Kidney-EP across quartiles of Gal-3 (overall HR 0.45 [95%CI 0.23, 0.85], p<0.0001; p-interaction = 0.97, Fig., B). However, there was greater absolute benefit of dapagliflozin with higher Gal-3 (ARR Q4 1.9 [95% CI 0.6, 3.2] vs. Q1 0.6% [-0.1, 1.3], ARR p-trend 0.048).

Conclusion: Plasma Gal-3 is associated with progression of kidney dysfunction in patients with T2DM independently of patient characteristics, including baseline kidney function. Moreover, Gal-3 identified an increasing gradient of absolute benefit of dapagliflozin for reducing kidney disease progression.