Evaluate the short-term economic outcomes of treating T2DM with canagliflozin v. sitagliptin (combined with metformin and a sulfonylurea) to achieve clinical goals from a managed care perspective.
Method: The one-year economic impact of using canagliflozin v. sitagliptin was estimated using a program that combined clinical outcomes and cost data. Data on efficacy and key adverse events (AEs) were obtained from a comparative trial of canagliflozin 300mg/day versus sitagliptin 100mg/day. Based on a claims database analysis, achieving (vs. not achieving) HbA1C<7% was assumed to result in $3,055/year and $1,651/year in total and diabetes-related savings. Based on literature, a 1% decrease in weight was associated with $288/year saved. AE-related costs (i.e., $105-$154/genital mycotic infections and $532/hypoglycemia requiring third-party assistance) were derived from treatment algorithms, literature, and reimbursement rates. Drug costs were literature-based. Total costs, average and incremental costs/key outcomes were calculated.
Result: Canagliflozin resulted in net savings of $581 compared to sitagliptin. Savings remained when sensitivity analyses were conducted. The average and incremental cost/key outcome favored canagliflozin.
Key Inputs/Results
|
Canagliflozin |
Sitagliptin |
Difference (Canagliflozin – Sitagliptin) |
Clinical Inputs / Outcomes |
|
|
|
% achieving HbA1C < 7% at week 52 |
47.6% |
35.3% |
+12.3% |
Absolute HbA1C reduction (%) from baseline |
1.03% |
0.66% |
0.37% |
% without treatment failure |
89.40% |
77.50% |
+11.90% |
% without severe hypoglycemic event |
96.00% |
96.60% |
-0.60% |
% weight change from baseline |
-2.5% |
+0.3% |
-2.8% |
% balanoposthitis (males) |
9.2% |
0.5% |
+8.7% |
% vulvovaginal candidiasis (females) |
15.3% |
4.3% |
+11% |
% urinary tract infections |
4.0% |
5.6% |
-1.6% |
Costs |
|
|
|
Drug-related costs |
$3,418 |
$3,210 |
$207 |
Non-drug costs |
$17,417 |
$18,206 |
-$788 |
Weight-related (change from baseline) |
-$470 |
$56 |
-$527 |
Total medical |
$17,831 |
$18,120 |
-$289 |
AEs (infections + hypoglycemic events) |
$57 |
$30 |
$27 |
Total Cost |
$20,835 |
$21,416 |
-$581 |
Cost per Key Outcome |
|
|
|
Cost/patient achieving HbA1C <7% (week 52) |
$43,772(a) |
$60,669(a) |
Canagliflozin dominates(b) |
Cost/1% change HbA1c |
$20,228(a) |
$32,449(a) |
Canagliflozin dominates(b) |
Cost/patient without treatment failure |
$23,306(a) |
$27,634(a) |
Canagliflozin dominates(b) |
Cost/patient without severe hypoglycemia event |
$21,703(a) |
$22,170(a) |
Sitagliptin costs $96,833/patient without severe hypoglycemic event(c) |
(a)Within-treatment
(b)Incremental cost/difference; Canagliflozin less expensive/more efficacious (HbA1C, weight) than sitagliptin.
(c)Incremental cost/difference; Sitagliptin more expensive and efficacious (marginally lower incidence severe hypoglycemia) than canagliflozin.
Conclusion:
This 52-week economic analysis suggests canagliflozin results in lower costs than sitagliptin. Cost per patient achieving HbA1C<7% metrics may provide additional insights in new therapy evaluations.