Use of Insulin Add-on insulin therapy is administered to participants who experience the primary outcome. In case of failure to maintain adequate metabolic control (HbA1c ≥ 8.0%), therapy is re-invigorated by more frequent telephone contact and visits. If HbA1c remains ≥ 8% throughout the next six months, then the patient is classified as failing to maintain adequate metabolic control and add-on therapy with insulin is initiated. In addition, some patients may require temporary suspension of study drug and use of insulin. This is referred to as ‘on leave’ and may be due to (1) temporary medical conditions such as hospitalization or intercurrent illness, (2) a sexually active female not on appropriate contraception, or (3) pregnancy. Any type or dose of insulin can be used at the discretion of the treatment team. Once the acute event has resolved, an attempt is made to withdraw insulin and resume study drugs.