Oral semaglutide is a tablet formulation of a glucagon-like peptide-1 receptor agonist (GLP-1RA), recently approved in the USA and other countries. This paper reviews data from clinical trials (PIONEER 1, 2, 3, and 7) comparing oral semaglutide (once-daily doses of 3, 7, or 14 mg) with either once-daily placebo, empagliflozin 25 mg, or sitagliptin 100 mg. After 26 weeks in PIONEER 1, patients randomized to 3, 7, or 14 mg doses of oral semaglutide monotherapy had statistically significant reductions in glycated hemoglobin (HbA1 c) of 0.9%, 1.2%, and 1.4%, respectively, versus 0.3% with placebo. In the active-comparator studies, oral semaglutide 14 mg provided better glycemic control than empagliflozin or sitagliptin after 26 weeks, with durable effects. Body weight reductions were significantly greater with oral semaglutide than with placebo and sitagliptin. However, body weight reductions with oral semaglutide 14 mg versus empagliflozin 25 mg were not significantly different. Gastrointestinal adverse events (AEs) with oral semaglutide were mostly mild-to-moderate, occurred early in the course of treatment, and abated over time. Across these trials, 5-13% and 15-20% of patients experienced nausea with oral semaglutide 7 and 14 mg, respectively, and 2.3-3.4% and 5.1-8.0%, respectively, discontinued treatment due to gastrointestinal AEs. Severe or blood glucose-confirmed symptomatic hypoglycemia occurred infrequently with oral semaglutide and was seen most often in patients taking concomitant sulfonylureas. Findings from these trials indicate that the addition of oral semaglutide reduces HbA1 c and body weight and is associated with a low risk of hypoglycemia. Oral semaglutide represents an additional option for treating people with type 2 diabetes in primary care, with the potential to expand the numbers of patients benefiting from GLP-1RAs beyond that currently seen with injectable formulations.
Keywords: Oral semaglutide; comparative studies; empagliflozin; sitagliptin; treatment intensification; type 2 diabetes.