SURPASS Clinical Trial Programme
The SURPASS programme is a series of six Phase 3 randomised controlled trials (SURPASS-1 through SURPASS-6) conducted between 2019 and 2023 to establish tirzepatide’s efficacy and safety in Type 2 diabetes. The trials were designed to cover the full spectrum of T2D treatment: from drug-naive patients on diet and exercise alone (SURPASS-1) to patients already on basal insulin requiring intensification (SURPASS-6). All six trials were funded and sponsored by Eli Lilly and Company.
The programme’s design allowed head-to-head comparisons against all major injectable diabetes treatment classes: semaglutide 1 mg (the leading GLP-1 receptor agonist, SURPASS-2), once-daily insulin degludec (SURPASS-3), once-daily insulin glargine in high-cardiovascular-risk patients (SURPASS-4), and prandial insulin lispro added to basal insulin (SURPASS-6). Tirzepatide was superior to all active comparators on the primary endpoint of HbA1c reduction in all trials. The programme was the basis for FDA approval in May 2022.
A notable limitation of the SURPASS programme is that it was entirely industry-funded with no independent replication at equivalent scale. Most populations were overweight or obese (BMI 31.9–35.8 kg/m²) and on metformin background. Patients with severe renal impairment (eGFR <30), very advanced T2D, or significant frailty were generally excluded. The mean age across trials (54–58.8 years) means patients over 70 years, or those with established sarcopenia or lean mass concerns, are underrepresented. Cardiovascular outcomes were adjudicated in SURPASS-4 (not powered for MACE as primary endpoint; HR 0.74, 95% CI 0.51–1.08 — suggestive but inconclusive).
Ontology SURPASS Clinical Trial Programme [part-of] Tirzepatide SURPASS Clinical Trial Programme [studied_in] SURPASS-1 SURPASS Clinical Trial Programme [studied_in] SURPASS-2 SURPASS Clinical Trial Programme [studied_in] SURPASS-4 SURPASS Clinical Trial Programme [studied_in] SURPASS-6 SURPASS Clinical Trial Programme [relates] HbA1c Reduction SURPASS Clinical Trial Programme [relates] Insulin-Use Reduction SURPASS Clinical Trial Programme [relates] Type 2 Diabetes
Key Results (Programme Overview)
- HbA1c reduction: −1.87% to −2.58% across all trials vs all comparators; consistently dose-dependent (5 < 10 < 15 mg)
- Target attainment: 43–92% of patients reached HbA1c <7.0% vs 4–36% on comparators
- Weight loss: −7.0 to −14.0 kg across trials
- Hypoglycaemia: Low with tirzepatide monotherapy or vs placebo; substantially lower than insulin comparators, especially when sulfonylurea not co-prescribed
- GI adverse events: Nausea 12–26%, diarrhoea 11–22%, vomiting 2–13% — mostly mild-moderate, peak during dose escalation
- Treatment discontinuation due to AE: 3–11% on tirzepatide vs 1–4% on comparators
- MACE (SURPASS-4): HR 0.74 (95% CI 0.51–1.08) vs insulin glargine — not powered as primary
Limitations
- Trial design: Open-label for comparisons against insulin (blinding not feasible); full blinding only vs placebo (SURPASS-1, -5)
- Population: Predominantly overweight/obese, on metformin, mean age 54–58.8 years; limited representation of patients ≥70, frail, or with advanced nephropathy
- Duration: Max 104 weeks (SURPASS-4); no long-term (>2 year) glycaemic trajectory or safety data beyond the trial period
- Sponsorship: All trials Eli Lilly-funded; no independent Phase 3 replication; most trial site investigators had financial ties to manufacturer
Connections
- Tirzepatide — studied_in, [2019–2023], source: FDA approval basis
- HbA1c Reduction — measured_by, [2021–2023]
- Insulin-Use Reduction — measured_by, [2021–2023]
- Semaglutide — comparator_in, [2021], source: SURPASS-2
- Insulin Glargine — comparator_in, [2021–2022], source: SURPASS-4
- Insulin Degludec — comparator_in, [2021], source: SURPASS-3
- Insulin Lispro — comparator_in, [2023], source: SURPASS-6
- Kidney Outcomes — measured_by (post-hoc), [2022], source: PMID 36152639