Impact of Liraglutide to Semaglutide Conversion on Glycemic Control and Cost Savings at a Veterans Affairs Medical Center
Background: Semaglutide and liraglutide are glucagon-like peptide 1 receptor agonists (GLP-1 RAs) approved by the US Food and Drug Administration for patients with type II diabetes mellitus (T2DM). Patients with T2DM treated with liraglutide at the Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC) were converted to semaglutide. The primary objective was to assess changes in glycemic control and cost savings that resulted from this conversion.
Methods: We conducted a retrospective chart review of veterans without retinopathy treated at MEDVAMC between March 1, 2021, and November 30, 2021, who were converted from liraglutide 0.6 mg and 1.2 mg daily to semaglutide 0.25 mg weekly (titrated to 0.5 mg weekly after 4 weeks). To assess glycemic control, we compared hemoglobin A1c (HbA1c) values 3 to 12 months following conversion with baseline values. Cost savings were evaluated using outpatient pharmacy data.
Results: During the study, 411 patients were converted from liraglutide to semaglutide; 49 additional patients met the criteria for clinician education, and 14 were converted as a result. In total, 304 patients met the criteria for inclusion. At baseline, patients’ levels included: mean (SD) HbA1c, 8.1% (1.5); blood glucose, 187 (44.2) mg/dL; and body weight, 112.9 (23) kg. Three to 12 months postconversion, patients’ mean (SD) HbA1c significantly decreased to 7.6% (1.4) (P < .001), blood glucose decreased to 172.6 (39) mg/dL (P < .001), and body weight decreased to 105.2 (32.3) kg (P < .001). Cost savings exceeding $400,000 resulted from the conversion from liraglutide to semaglutide.
Conclusions: Conversion of liraglutide to semaglutide led to significant HbA1c decrease and weight loss and resulted in minimal changes to patients’ antihyperglycemic regimen. Common adverse effects included hypoglycemia and gastrointestinal intolerance. Due to the low conversion rate of liraglutide to semaglutide following education, a more effective method of education for clinicians to promote teleretinal imaging before conversion is warranted. Lastly, although the semaglutide cost savings initiative at MEDVAMC resulted in significant savings for the institution, a full cost-effective analysis is needed for further conclusion.
Methods
This QI project was a single-center, prospective cohort study with a retrospective chart review of veterans with T2DM converted from liraglutide to semaglutide at the MEDVAMC. Patient data were collected from the Computerized Patient Record System (CPRS) between March 1, 2021, and November 30, 2021. An initial subset of patients was converted to semaglutide in March and April 2021. Patients initially excluded underwent a second chart review to determine whether they truly met exclusion criteria. Patients who did not have a definitive diagnosis of NPDR or PDR, those due for updated teleretinal imaging, as well as those with updated teleretinal imaging that excluded NPDR or PDR were targeted for clinician education interventions.
Following this intervention, a subset of patients with negative DR findings were converted from liraglutide to semaglutide. Primary care and endocrinology clinicians were notified that patients who met the criteria should be referred for teleretinal imaging if no updated results were present or that patients were eligible for semaglutide conversion based on negative findings. Both patients who were initially converted as well as those converted following education were included for data collection/analysis of glycemic control via HbA1c and blood glucose levels.
Cost savings were evaluated using outpatient pharmacy procurement pricing data. This project was approved by the MEDVAMC Quality Assurance and Regulatory Affairs Office.
Participants
Patients included in the study were adults aged ≥ 18 years with T2DM, converted from liraglutide 0.6 and 1.2 mg daily to semaglutide 0.25 mg weekly (titrated to 0.5 mg weekly after 4 weeks), and had an active prescription for semaglutide, with or without insulin or other oral antihyperglycemics. Patients with NPDR or PDR, type 1 DM, no HbA1c data, no filled semaglutide prescriptions, insulin pumps, and those without teleretinal imaging within the postintervention period or who died during the study period were excluded.
Patient baseline characteristics collected included demographic data, CV comorbidities, antihyperglycemic medications, and changes in insulin doses. Parameters analyzed at baseline and 3 to 12 months postconversion included body weight, HbA1c, and blood glucose levels.
Outcomes
The primary objectives of this QI project were to assess glycemic control (via changes in HbA1c levels) and cost savings following patient conversion from liraglutide to semaglutide. A second objective was to educate clinicians for referral of T2DM patients without teleretinal imaging in the past 2 years.
The purpose of the latter objective was to encourage conversion from liraglutide to semaglutide in the absence of DR. We predicted that 50% of patients with clinician education would be converted. Secondary objectives included assessing body weight differences, evaluating modifications in diabetes regimen, and documenting AEs. We predicted that glycemic control would either remain stable or improve with conversion to semaglutide.
Statistical Analysis
Patient demographic data were analyzed using descriptive statistics. Quantitative data (HbA1c, blood glucose, and body weight differences as continuous variables) were analyzed using a paired Student t test, and categorical variables were analyzed using the χ2 test.
