A 35 year old woman with type 2 diabetes is seen in follow up. She is on metformin 1 g twice daily. Her HbA1c is 8.4% despite adherence, BMI 32 kg/m², eGFR 80 mL/min/1.73 m² and she has no established cardiovascular disease. According to Diabetes Canada, what is the most appropriate next step in pharmacologic management?