Dulaglutide
LY2189265, GLP-1-Fc fusion protein, dulaglutide injection, Trulicity
Dulaglutide is a once-weekly GLP-1 receptor agonist built as a recombinant fusion protein: a modified human GLP-1 peptide covalently linked to an immunoglobulin G4 Fc fragment. The Fc portion gives it a long half-life and, because it is cleared by general protein catabolism rather than by the kidney, it requires no dose adjustment in renal impairment. It is licensed for type 2 diabetes and, in some jurisdictions, for cardiovascular risk reduction.
Mechanism
Dulaglutide activates the GLP-1 receptor, producing the canonical incretin response: glucose-dependent potentiation of insulin secretion, suppression of inappropriate glucagon release, slowed gastric emptying and centrally mediated appetite reduction. What distinguishes it is the engineering. The GLP-1 portion carries three deliberate substitutions: alanine 8 to glycine removes the DPP-4 cleavage site; glycine 22 to glutamate reduces the tendency to aggregate and lowers immunogenic potential; and arginine 36 to glycine further stabilises the molecule. The Fc fragment is derived from human IgG4 and is itself modified to prevent Fab-arm exchange and to minimise binding to Fc-gamma receptors and complement, so that the fusion protein does not trigger immune effector functions.
The practical effect of the Fc domain is twofold. Its size, roughly 60 kDa, places it well above the renal filtration threshold, so elimination proceeds through ordinary proteolytic catabolism rather than glomerular filtration. Neonatal Fc receptor binding recycles the molecule out of the endosomal degradation pathway and back into circulation. Together these give a half-life of about five days. The molecule is a partial rather than full agonist at the receptor when measured against native GLP-1, but circulating concentrations are high enough for maximal clinical effect.
What the research shows
The AWARD programme placed dulaglutide against most of the relevant comparators. AWARD-6 was the pivotal head-to-head against liraglutide 1.8 mg in 599 adults: once-weekly dulaglutide 1.5 mg was non-inferior on HbA1c (reductions of 1.42 versus 1.36 percentage points over 26 weeks, treatment difference -0.06, 95% CI -0.19 to 0.07) but produced slightly less weight loss (2.90 versus 3.61 kg). AWARD-1 showed superiority over twice-daily exenatide. AWARD-11 randomised 1,842 adults and found that escalating from 1.5 mg to 4.5 mg improved HbA1c reduction to 1.77 percentage points and weight loss to about 4.6 kg at the 36-week primary endpoint, though with diminishing incremental returns and more gastrointestinal intolerance.
REWIND is the most consequential trial. It enrolled 9,901 people with type 2 diabetes, of whom roughly 69% had no established cardiovascular disease, and followed them for a median of 5.4 years. Major adverse cardiovascular events occurred in fewer dulaglutide recipients (hazard ratio 0.88, 95% CI 0.79-0.99). This was the first GLP-1 receptor agonist outcome trial with a majority primary-prevention population to show benefit. The absolute risk reduction was modest, roughly 1.4 events per 100 person-years versus 1.6, and the effect was driven largely by non-fatal stroke rather than cardiovascular death.
Evidence assessment
High-quality evidence
Dulaglutide holds approved labelling in the United States, European Union and United Kingdom, supported by the multi-trial AWARD phase 3 programme including several active-comparator head-to-head studies, and by REWIND, a 9,901-participant cardiovascular outcomes trial with a median 5.4 years of follow-up that demonstrated a significant reduction in major adverse cardiovascular events. All four cited studies were individually verified.
Tiers are applied consistently across the library and re-checked when new trials read out. Read the grading method.
Key studies
Once-weekly dulaglutide versus once-daily liraglutide in metformin-treated patients with type 2 diabetes (AWARD-6): a randomised, open-label, phase 3, non-inferiority trial Preclinical only
Dulaglutide 1.5 mg weekly was non-inferior to liraglutide 1.8 mg daily on HbA1c (reductions of 1.42 versus 1.36 percentage points, treatment difference -0.06, 95% CI -0.19 to 0.07) but produced less weight loss (2.90 versus 3.61 kg).
Efficacy and safety of dulaglutide added onto pioglitazone and metformin versus exenatide in type 2 diabetes in a randomized controlled trial (AWARD-1) Preclinical only
Both dulaglutide doses were superior to twice-daily exenatide and to placebo for HbA1c reduction at 26 weeks, with effects maintained to 52 weeks.
Dulaglutide and cardiovascular outcomes in type 2 diabetes (REWIND): a double-blind, randomised placebo-controlled trial Preclinical only
Major adverse cardiovascular events were reduced (hazard ratio 0.88, 95% CI 0.79-0.99, p=0.026) in a cohort in which roughly 69% had no established cardiovascular disease. The benefit was driven principally by non-fatal stroke.
Efficacy and Safety of Dulaglutide 3.0 mg and 4.5 mg Versus Dulaglutide 1.5 mg in Metformin-Treated Patients With Type 2 Diabetes in a Randomized Controlled Trial (AWARD-11) Preclinical only
Escalating to 4.5 mg weekly gave an HbA1c reduction of 1.77 percentage points and weight loss of about 4.6 kg, versus 1.54 points and 3.0 kg at 1.5 mg, with more gastrointestinal adverse effects at higher doses.
Safety
Gastrointestinal effects dominate: nausea, diarrhoea, vomiting and dyspepsia, usually early and dose-related. Injection-site reactions are uncommon. Hypoglycaemia is rare with dulaglutide alone but common when combined with a sulfonylurea or insulin. The label carries the class boxed warning for thyroid C-cell tumours based on rodent carcinogenicity data, contraindicating use in personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2; the human relevance of this signal remains unestablished. Acute pancreatitis has been reported and warrants discontinuation if suspected. Gallbladder disease, including cholelithiasis and cholecystitis, occurs more often than with placebo. Rapid improvement in glycaemic control can transiently worsen diabetic retinopathy. Because elimination does not depend on the kidney, no dose adjustment is needed in renal impairment, but dehydration from vomiting or diarrhoea can still precipitate acute kidney injury.
Regulatory status
| Jurisdiction | Status |
|---|---|
| United Kingdom | Authorised across the European Union from November 2014 and subsequently converted to a Great Britain marketing authorisation regulated by the MHRA, with Northern Ireland supply running under EU rules. Indicated for type 2 diabetes as monotherapy where metformin is inappropriate and as add-on therapy. Prescription-only medicine; not a controlled drug. NICE guidance positions GLP-1 receptor agonists within the type 2 diabetes treatment pathway subject to response criteria. It is not licensed in the UK for weight management, and the UK licence does not carry the separate cardiovascular risk-reduction indication granted in the United States. |
| United States | Approved by the FDA in September 2014 as an adjunct to diet and exercise to improve glycaemic control in adults with type 2 diabetes. In February 2020 the indication was expanded to reduce the risk of major adverse cardiovascular events in adults with type 2 diabetes who have established cardiovascular disease or multiple cardiovascular risk factors, extending licensed cardiovascular risk reduction to a population that includes primary prevention. Paediatric use from age 10 was added in 2022. It is not approved for weight management. Prescription-only. |
| WADA (sport) | Not prohibited. Dulaglutide does not appear on the WADA Prohibited List, and GLP-1 receptor agonists are not banned as a class. WADA's separate Monitoring Programme is revised annually, carries no sanctions, and should be checked against the list in force for the relevant year. |
Questions
Both, strictly speaking. It is a recombinant fusion protein of roughly 60 kDa in which a modified GLP-1 peptide is genetically fused to an antibody Fc fragment. It cannot be chemically synthesised like exenatide or semaglutide; it is produced in mammalian cell culture.
Its size keeps it above the glomerular filtration threshold, so it is eliminated by ordinary protein catabolism rather than renal clearance. Peptide agonists such as exenatide and lixisenatide are filtered by the kidney and accumulate when renal function declines.
REWIND showed a statistically significant 12% relative reduction in major adverse cardiovascular events over a median 5.4 years, in a population mostly without established cardiovascular disease. The absolute benefit was small and driven mainly by non-fatal stroke, but the finding supported a licensed cardiovascular indication in the United States.
Typically 2-5 kg depending on dose, less than liraglutide 1.8 mg at the 1.5 mg dose and considerably less than semaglutide or tirzepatide. It is licensed for glycaemic control, not for weight management, and weight loss is best regarded as a secondary effect.