Clinical Effectiveness and Impact on Insulin Therapy Cost After Addition of Dapagliflozin to Patients with Uncontrolled Type 2 Diabetes

INTRODUCTION: Dapagliflozin, a sodium glucose co-transporter 2 (SGLT2) inhibitor, is a promising drug approved for the treatment of type 2 diabetes mellitus (T2DM). However, its cost is an obstacle for use in developing countries like India. Thus, we aimed to analyse the impact on the cost of insulin therapy after adding dapagliflozin for patients using insulin in real-world clinical practice. METHODS: This retrospective chart review study included patients with uncontrolled T2DM previously on maximum doses of OADs and insulin therapy, initiated on dapagliflozin. Parameters measured were: HbA1c, changes in weight and insulin dosage, frequency and cost, at baseline and after 3 months of adding dapagliflozin 10 mg. Hospital records of patients attending the diabetes outpatient departments at the study centres were scrutinised to identify eligible patients. A treat-to-target approach was used to make changes in the insulin dosages and regimen. The cost of insulin was calculated based on the total daily dose, cost per unit based on the formulation and insulin delivery device. Statistical analysis included descriptive and inferential methods. RESULTS: Overall, 70 patients meeting the inclusion criteria were included in the study. The mean age of patients and duration of T2DM were 52.6 ± 10 and 12 ± 5 years respectively. The mean reduction in HbA1c and weight was 2.1 ± 1% (p < 0.01) and 2.4 ± 1 kg (p < 0.01) respectively. Genital mycotic infections were reported in two (2.8%) patients. The mean reduction in the total daily dose of insulin was 9.5 ± 6 units. A significant reduction in the daily insulin requirement (19.87%, p < 0.01) was observed. The cost of insulin decreased by 22.3% or 17.8 ± 15 INR per day ($0.27 ± 0.22 per day) and the frequency of insulin shots administered per day decreased significantly (p < 0.01). In 12.8% and 2.8% of patients the frequency of administration of insulin decreased by one and two injections per day respectively. CONCLUSIONS: Reduction in HbA1c and body weight along with minimal side effects was observed. Addition of dapagliflozin reduced the insulin daily dose requirement and cost of insulin therapy in these patients. FUNDING: Diacon Hospital, Bangalore, India.