A Study to Evaluate the Safety and Efficacy of CCX140-B in Subjects With Diabetic Nephropathy

Key Inclusion Criteria: * Aged 18-75 years inclusive, with documented previously diagnosed type 2 diabetes mellitus (per American Diabetes Association \[ADA\] criteria) * Residual albuminuria despite stable treatment with an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB) for at least 8 weeks prior to screening (Albumin:creatinine ratio \[ACR\] of 100 to 3000 mg/g creatinine, inclusive) * Estimated glomerular filtration rate based on serum creatinine (eGFR, determined by Modification of Diet in Renal Disease \[MDRD\] equation) of ≥ 25 mL/min/1.73 m(2) * Must be on a stable dose of an ACE inhibitor or ARB for at least 8 weeks prior to screening, but subjects must not be on both an ACE inhibitor and an ARB * Hemoglobin A1c (HbA1c) \> 6.0% but not \> 10.0% and fasting plasma glucose less than 270 mg/dL at screening Key Exclusion Criteria: * Type 1 diabetes mellitus or history of diabetic ketoacidosis * Previous renal transplant or known non-diabetic renal disease, except related to hypertension * Undergone renal dialysis at any time in the past * Received chronic (more than 7 days continuously) systemic glucocorticoid or other immunosuppressive treatment within 8 weeks of screening * Use of bardoxolone, atrasentan or other endothelin antagonist within 8 weeks of screening * Received chronic (more than 7 days continuously) non-steroidal anti-inflammatory drug (NSAID) treatment within 2 weeks of screening * Cardiac failure (class III or IV), history of unstable angina, symptomatic coronary artery disease, myocardial infarction or stroke within 12 weeks of screening * Poorly-controlled blood pressure (systolic blood pressure \>155 or diastolic blood pressure \>95, with blood pressure measured in the seated position after at least 5 minutes of rest)