Tirzepatide ↗ cleared 60.2 percent of patients with early type 2 diabetes into normoglycemia (HbA1c under 5.7 percent, the diabetes-association cutoff for non-diabetic blood sugar) over two years. The control arm in the same trial was allowed to use any glucose-lowering drug in current practice, including other GLP-1 receptor agonists, with the single exclusion of tirzepatide itself. That arm hit 24.0 percent.
SURPASS-EARLY, published online May 26 in Annals of Internal Medicine ↗, is the first phase 4 trial to put tirzepatide head-to-head against best-of-current-care rather than against placebo or a single comparator drug. The 794 adults enrolled had at most four years of type 2 diabetes, were on metformin, and had inadequate glycemic control. They were randomized open-label across 78 sites in 10 countries to tirzepatide 15 mg weekly (or the maximum dose they could tolerate) or to "intensified conventional care," which the protocol defined as whatever combination of guideline-aligned therapies their physician would otherwise pick. That deliberately included semaglutide ↗, dulaglutide, and liraglutide on the GLP-1 side, plus SGLT2 inhibitors, sulfonylureas, and basal insulin. Eli Lilly funded the trial.
What moved
Tirzepatide was superior on every prespecified endpoint that mattered.
HbA1c fell by 1.99 percentage points on tirzepatide and by 1.32 on conventional care. The treatment difference was 0.68 percentage points (95 percent confidence interval 0.51 to 0.84), meaning tirzepatide patients ended the trial with HbA1c roughly two-thirds of a point lower than what their own physicians would have achieved using anything else on the formulary.
Body weight dropped 8.0 kg further on tirzepatide than on the comparator (95 percent CI 6.5 to 9.4 kg). Waist circumference dropped 6.2 cm further (95 percent CI 4.9 to 7.5 cm). Both differences are larger than what any head-to-head between two GLP-1 receptor agonists has produced to date.
The normoglycemia number is the one that does the real work. HbA1c under 5.7 percent is the American Diabetes Association threshold for not having diabetes. Crossing it on a drug is not the same as remission (the patient is still on the drug) but it is the closest practical proxy without a withdrawal protocol. Sixty percent of the tirzepatide arm crossed. A quarter of the comparator arm did. The comparator arm was using the same GLP-1 receptor agonists the rest of the world is using to manage early type 2 diabetes.
What it doesn't say
The trial was open-label, which is the standard limitation Annals flagged. Patients and physicians knew which arm they were in. For a clinical-practice question (does adding tirzepatide do more than what we would do anyway) the open-label design is defensible, but it caps how cleanly the result can be read as a pure pharmacological comparison.
Adverse events were mostly gastrointestinal in both arms, which is consistent with the GLP-1 mechanism class on both sides of the trial. The abstract does not break out the per-drug AE comparisons within the conventional-care arm, so the readout cannot yet tell whether the tolerability of tirzepatide 15 mg ran differently from the mixed-drug comparator at the dose distributions used in actual clinic.
The result does not answer how durable the normoglycemia is after the drug stops. SURPASS-EARLY measured at two years on treatment. The post-discontinuation rebound that has dogged every GLP-1 obesity trial applies here too until someone runs a withdrawal arm.
Why this matters
Tirzepatide's earlier phase 3 SURPASS program (the original SURPASS-1 through SURPASS-5) compared tirzepatide against placebo, against insulin glargine, against semaglutide 1 mg, and against insulin degludec. Each of those was a single-comparator trial, useful for regulatory approval but not for the clinical question physicians actually ask: if I add tirzepatide instead of doing what I would otherwise do, how much do I gain? SURPASS-EARLY is the first time that question was asked with the comparator open to whatever the physician would have chosen.
The answer (tirzepatide opens roughly a 2.5-fold gap in normoglycemia rate against the best alternative the field can currently assemble) is the structural news. It is not that tirzepatide is the better drug. The phase 3 program had already shown that. It is that the gap against the next-best option is wider than what a head-to-head against a single comparator was able to show, because in clinical practice no single comparator is ever used.
Tirzepatide is a dual GIP and GLP-1 receptor agonist. The card carries the trial and label history; the GLP-1R ↗ and GIPR ↗ target pages list the rest of the dual-agonist pipeline against the same receptor pair.