The intervention group in Cohort 1 will be those randomised to metformin + Canagliflozin (Invokana™). The control group in Cohort 1 will be those randomised to receive metformin plus repaglinide, or a sulphonylurea or pioglitazone in line with current National Institute for Health and Care Excellence (NICE) guidance as the preferred second-line therapy after metformin.