BACKGROUND: The sodium-glucose cotransporter 2 (SGLT2) inhibitors, which include 
canagliflozin, dapagliflozin, and empagliflozin, represent a new class of 
antihyperglycemic agents. Few studies have assessed their cost per response, 
with "cost per response" being the total cost of a select drug, divided by the 
resulting change in glycated hemoglobin (HbA1c) levels.
OBJECTIVE: To examine the drug cost of SGLT2 inhibitors per a reduction in 
placebo-adjusted 1% HbA1c in patients with type 2 diabetes mellitus who received 
treatment during 26 weeks with canagliflozin, dapagliflozin, or empagliflozin.
METHODS: The drug cost per response for each of the 3 agents individually was 
assessed based on data from a subset of clinical trials discussed in the 
prescribing information for each drug that were all placebo-controlled studies 
evaluating each drug as monotherapy, dual therapy (combined with metformin), and 
triple therapy (combined with metformin and a sulfonylurea) in patients with 
uncontrolled, type 2 diabetes mellitus. The US 2015 wholesale acquisition cost 
for each drug was used to calculate each drug's treatment costs over 26 weeks. 
The average cost per response for each drug was defined as the prescription drug 
cost of each SGLT2 inhibitor, divided by the average, placebo-adjusted HbA1c 
reduction at 26 weeks.
RESULTS: The drug cost per unit dose was the same for canagliflozin (100 mg or 
300 mg), dapagliflozin (5 mg or 10 mg), and empagliflozin (10 mg or 25 mg), at 
$11.43. The drug cost per placebo-adjusted 1% HbA1c reduction varied by agent 
and by dose, as a result of the differences in the treatment responses for each 
of the 3 drugs. The costs per response for canagliflozin 100 mg as monotherapy, 
dual therapy, and triple therapy regimens ranged from $2286 to $3355, and for 
canagliflozin 300 mg, from $1793 to $2702. The costs per response for 
dapagliflozin 5 mg as monotherapy and dual therapy (triple therapy was not 
available at the time of the study) ranged from $4161 to $5201; the cost for 
dapagliflozin 10 mg ranged from $2972 to $4161. The costs per response for 
empagliflozin 10 mg ranged from $2972 to $3467 across the monotherapy, dual 
therapy, and triple therapy regimens; the cost for empagliflozin 25 mg ranged 
from $2311 to $3467.
CONCLUSION: Simple analyses, such as the drug cost per placebo-adjusted 1% 
reduction in HbA1c, may be useful when considering the addition of 
antihyperglycemic agents to the health plan's formulary.