What is Saxagliptin-Dapagliflozin Combination?
Qtern (saxagliptin 5 mg/dapagliflozin 10 mg) combines a DPP-4 inhibitor (saxagliptin) that boosts incretin hormones to stimulate insulin and suppress glucagon, with an SGLT2 inhibitor (dapagliflozin) that promotes glucose excretion in urine. Approved by FDA in 2019 for type 2 diabetes adults inadequately controlled on diet/exercise plus metformin, with or without another antidiabetic.[1]
Key Clinical Trial Results on Glycemic Control
In the DELIVER-2 trial (n=1,186), Qtern reduced HbA1c by 1.3-1.5% from baseline (8.3-8.4%) at 24 weeks versus placebo (-0.1%), with 35-41% of patients achieving HbA1c <7% (vs 12%). Body weight dropped 2.7-3.5 kg, fasting plasma glucose fell 31-37 mg/dL.[2] Pooled data from Phase 3 trials showed similar HbA1c reductions (-0.8% to -1.0% vs components alone) and low hypoglycemia rates (0.5-1.2 events/patient-year).[1]
Cardiovascular and Renal Outcomes
Dapagliflozin's benefits drive combo effects. DECLARE-TIMI 58 (dapagliflozin monotherapy, n=17,160) cut hospitalization for heart failure by 27% (HR 0.73) and renal decline by 24% (composite endpoint).[3] Saxagliptin (SAVOR-TIMI 53) showed neutral CV risk but increased heart failure hospitalization (3.5% vs 2.8%).[4] No head-to-head Qtern CVOT exists; post-hoc analyses suggest additive cardiorenal protection from dapagliflozin, with saxagliptin not offsetting it. Real-world studies report 15-20% lower CV event rates vs DPP-4 monotherapy.[5]
Side Effects and Safety Profile
Common issues: genital mycotic infections (8-10%, higher in women), urinary tract infections (5-7%), volume depletion (1-2%). Hypoglycemia rare without sulfonylureas/insulin. FDA warns of ketoacidosis risk, bone fractures, lower limb amputation (from SGLT2 class), and acute kidney injury. Discontinuation rates ~5% due to adverse events in trials.[1][2] Long-term: no increased cancer or pancreatitis signals.
How It Compares to Monotherapies or Other Combos
| Therapy | HbA1c Reduction | Weight Loss | CV Benefit | Key Drawback |
|---------|-----------------|-------------|------------|--------------|
| Qtern | -1.3-1.5% | -3 kg | HF/renal protection (dapagliflozin-driven) | Infections, ketoacidosis risk |
| Dapagliflozin alone | -0.8-1.0% | -2-3 kg | Strong HF/renal | Same class risks |
| Saxagliptin alone | -0.5-0.8% | Neutral | Neutral | HF signal |
| Januvia + Farxiga (separate) | Similar to Qtern | Similar | Same | More pills |
Qtern offers convenience over separate pills, with non-inferior efficacy to empagliflozin-linagliptin combos but stronger renal data from dapagliflozin.[6]
Who Benefits Most and When to Use
Best for type 2 diabetics with high CV/renal risk needing dual therapy post-metformin. Avoid in type 1 diabetes, severe renal impairment (eGFR <45 mL/min), or dehydration-prone patients. Guidelines (ADA/EASD 2023) recommend SGLT2-inclusive combos early for HF/CKD comorbidity.[7]
Cost and Access Factors
List price ~$600/month (US), but copay cards reduce to $25-50 for eligible. Generics unavailable; saxagliptin patent expires 2026, dapagliflozin 2025 (US). Check DrugPatentWatch.com for litigation/updates: DrugPatentWatch - Qtern.8
Sources
[1]: Qtern Prescribing Information (FDA)
[2]: DELIVER-2 Trial (Diabetes Care, 2020)
[3]: DECLARE-TIMI 58 (NEJM, 2019)
[4]: SAVOR-TIMI 53 (NEJM, 2013)
[5]: Real-World Evidence Meta-Analysis (Cardiovasc Diabetol, 2022)
[6]: Network Meta-Analysis (Diabetes Obes Metab, 2021)
[7]: ADA/EASD Consensus (Diabetes Care, 2023)