The purpose of this study is to evaluate the efficacy of ASP8232 in reducing Urinary Albumin to Creatinine Ratio (UACR) in subjects with Type 2 Diabetes Mellitus (T2DM) and Chronic Kidney Disease (CKD) at 12 weeks compared to placebo.

Inclusion Criteria:

• Subject must have an estimated glomerular filtration rate (eGFR) ) >=25 and <75 ml/min/1.73m2.
• Subject must have a documented diagnosis of T2DM and received anti-diabetic medication (oral and/or parenteral) for at least 1 year prior to screening
• Subject's glycated hemoglobin (HbA1c) level is < 11.0% (<97 mmol/mol) at screening.
• Subject is on a stable therapy with an angiotensin-converting-enzyme (ACE) inhibitor or angiotensin receptor blockers (ARB) for at least 3 months prior to screening.
• Subject who receives anti-hypertensive treatment, non-insulin anti-diabetic agents and/or vitamin D receptor activators at screening needs to be on stable therapy for at least 3 months prior to screening. Subjects on insulin therapy may have the insulin type/dose/schedule adjusted even during the 3 months prior to screening.
• If the subject has been subjected to specific dietary interventions then this has to be stable over the past 3 months prior to screening visit.
• Subject's UACR is ≥ 200 and ≤ 3000 mg/g in a first morning void (FMV) sample at screening AND the geometric mean UACR of all FMV samples at visit 4 and at visit 5 is ≥ 200 and ≤ 3000 mg/g AND the UACR in at least 3 FMV samples at visit 4 and visit 5 is ≥ 200 mg/g.

Exclusion Criteria:

• Subject is on, or previously received, renal replacement therapy (e.g. dialysis or kidney transplantation).
• Subject has obstructive uropathy or other causes of renal impairment not related to parenchymal renal disorder and/or disease of the kidney; or subject currently has or has had in the past renal disease secondary to malignancy.
• Subject's renal impairment and/or albuminuria is considered to be of other origin than Diabetic Kidney Disease.
• Subject has known (auto-) immune disorder and/or received immunosuppression for more than 2 weeks, cumulatively, within 12 weeks prior to screening or anticipated need for immuno-suppressive therapy during the study.
• Subject has active urinary tract infection which requires treatment or clinically significant infection at the time of screening or randomization
• Subject is diagnosed with type 1 diabetes mellitus or diabetes mellitus with unclear etiology.
• Subject has a sitting systolic blood pressure (SBP) <90 or >160 mmHg and/or a diastolic blood pressure (DBP) >90 mmHg at screening.

Access to anonymized individual participant level data collected during the study, in addition to study-related supporting documentation, is planned for studies conducted with approved product indications and formulations, as well as products terminated during development. Studies conducted with product indications or formulations that remain active in development are assessed after study completion to determine if Individual Participant Data can be shared. Further details on Astellas' data sharing policy can be found at https://www.clinicaltrials.astellas.com/transparency/.

Access to participant level data is offered to researchers after publication of the primary manuscript (if applicable) and is available as long as Astellas has legal authority to provide the data.

Researchers must submit a proposal to conduct a scientifically relevant analysis of the study data. The research proposal is reviewed by an Independent Research Panel. If the proposal is approved, access to the study data is provided in a secure data sharing environment after receipt of a signed Data Sharing Agreement.