Comparative Efficacy of Dulaglutide and GLP-1 Agonists

Dulaglutide vs other GLP-1 receptor agonists: differences in efficacy for HbA1c and postprandial glucose control?

Dulaglutide achieves similar or superior HbA1c reduction compared to liraglutide, consistent superiority over exenatide, and comparable efficacy to semaglutide when dose-matched, though postprandial glucose control data are limited and suggest semaglutide may have advantages in reducing glucose variability.

Abstract

Dulaglutide demonstrates non-inferior to superior HbA1c efficacy compared to other GLP-1 receptor agonists, with the magnitude of benefit varying by comparator. Dulaglutide 1.5 mg weekly was non-inferior to liraglutide 1.8 mg daily (-1.42% vs -1.36% HbA1c reduction), though meta-analysis of six studies suggested small superiority favoring dulaglutide at 6 months (-0.17%, 95% CI -0.26 to -0.08) and 12 months (-0.22%, 95% CI -0.32 to -0.11). Against exenatide 10 μg twice daily, dulaglutide showed consistent superiority with 0.4-0.6% greater HbA1c reductions at both 26 and 52 weeks (P<0.001). Compared to semaglutide, dulaglutide 1.5 mg achieved similar glycemic control to semaglutide 0.5 mg, though semaglutide demonstrated superiority when initiated in patients already receiving stable dulaglutide therapy (-0.4% vs +0.2%, p=0.006).

Postprandial glucose control data were limited, with only two studies providing specific assessments. Dulaglutide showed greater reductions in premeal and postprandial glucose levels than exenatide at midday and evening meals, though exenatide achieved superior 2-hour postprandial glucose excursion reduction. Semaglutide reduced postprandial hyperglycemia across all meals more effectively than dulaglutide and improved multiple glucose variability metrics including standard deviation (p=0.005), mean amplitude of glycemic excursions (p=0.013), time above range (p=0.039), and time in range (p=0.031). The comparative efficacy hierarchy appears influenced by dose selection, with dulaglutide 1.5 mg consistently outperforming 0.75 mg, and by pharmacokinetic differences between rapid-acting, intermediate-acting, and long-acting GLP-1 receptor agonists.

Methods

We analyzed 10 sources from an initial pool of 200, using 6 screening criteria. Each paper was reviewed for 6 key aspects that mattered most to the research question. More on methods

Records from Elicit search

n = 200

Papers screened using: Population Age and Diabetes Type, Study Comparison, Efficacy Outcomes, Study Design, Study Duration, Drug Administration

n = 200

Papers screened out

n = 190

Papers included for extraction

n = 10

Paper search

We performed a semantic search across over 138 million academic papers from the Elicit search engine, which includes all of Semantic Scholar and OpenAlex.

We ran this query: “Dulaglutide vs other GLP-1 receptor agonists: differences in efficacy for HbA1c and postprandial glucose control?”

The search returned 200 total results from Elicit.

We retrieved 200 papers most relevant to the query for screening.

Screening

We screened in sources based on their abstracts that met these criteria:

• Population Age and Diabetes Type: Does this study include adults (≥18 years) with type 2 diabetes mellitus (and exclude patients with type 1 diabetes or gestational diabetes)?
• Study Comparison: Does this study compare dulaglutide directly with at least one other GLP-1 receptor agonist?
• Efficacy Outcomes: Does this study report HbA1c levels and/or postprandial glucose measurements?
• Study Design: Is this study a randomized controlled trial, systematic review, or meta-analysis (and not a preclinical study, in vitro study, animal study, case report, case series, or editorial)?
• Study Duration: Does this study have a minimum follow-up duration of 12 weeks or longer?
• Drug Administration: Is dulaglutide used as a single GLP-1 receptor agonist (not in combination with other GLP-1 receptor agonists)?

We considered all screening questions together and made a holistic judgement about whether to screen in each paper.

Characteristics of Included Studies

This review included 10 sources examining dulaglutide compared to other GLP-1 receptor agonists. Three sources provided full text data, while seven were available only as abstracts. The evidence base comprised six primary randomized controlled trials, three meta-analyses or systematic reviews, and one post-hoc pooled analysis.

HbA1c Efficacy

Dulaglutide versus Liraglutide

Direct head-to-head comparison in the AWARD-6 trial demonstrated non-inferiority of dulaglutide 1.5 mg weekly to liraglutide 1.8 mg daily. The least-squares mean HbA1c reduction was -1.42% for dulaglutide compared to -1.36% for liraglutide, with a between-group difference of -0.06% (95% CI -0.19 to 0.07, p<0.0001 for non-inferiority). Non-inferiority was established using a 0.4% margin.

The meta-analysis by Ye et al. including three RCTs and three observational studies (N=5,817) found dulaglutide superior to liraglutide for HbA1c reduction. At 6 months, dulaglutide showed a mean difference of -0.17% (95% CI -0.26 to -0.08), and at 12 months, -0.22% (95% CI -0.32 to -0.11). However, liraglutide demonstrated superior weight loss, with dulaglutide showing 0.34 kg less weight reduction at 6 months (95% CI 0.05 to 0.65).

Dulaglutide versus Exenatide

Dulaglutide demonstrated superior HbA1c reduction compared to twice-daily exenatide across multiple studies. In the AWARD-1 trial (N=978), dulaglutide 1.5 mg reduced HbA1c by -1.51% versus -0.99% for exenatide 10 μg at 26 weeks, with superiority maintained at 52 weeks (-1.36% vs -0.80%, between-group difference -0.56%, P<0.001). The lower dulaglutide dose of 0.75 mg also showed superior efficacy (-1.30% at 26 weeks). The systematic review by Gurung reported similar findings, with dulaglutide 1.5 mg achieving -1.5% HbA1c reduction versus -0.99% for exenatide.

Dulaglutide versus Semaglutide

Three analyses from the SUSTAIN 7 trial compared semaglutide to dulaglutide. Schmidt et al. reported that at 40 weeks, HbA1c improvements were similar or favored semaglutide across baseline HbA1c subgroups (p=0.02 for interaction). More subjects with baseline HbA1c >9% achieved HbA1c targets with semaglutide versus dulaglutide.

In a post-hoc comparison of clinically available doses, Pratley et al. found similar glycemic control between semaglutide 0.5 mg and dulaglutide 1.5 mg at week 40, though semaglutide showed greater weight loss.

The prospective study by Omachi et al. demonstrated semaglutide 0.5 mg superiority over dulaglutide 0.75 mg in a population already treated with dulaglutide. After 24 weeks, the dulaglutide group showed minimal change (+0.2% ± 0.6%) while semaglutide reduced HbA1c by -0.4% ± 0.5% (p=0.006).

Summary Table of HbA1c Efficacy

The magnitude of HbA1c reduction with dulaglutide ranged from -0.76% to -1.51% across studies, with the higher 1.5 mg dose consistently outperforming the 0.75 mg dose. When compared to liraglutide, findings were mixed: one primary trial showed non-inferiority, while a meta-analysis suggested small but statistically significant superiority of dulaglutide. Against exenatide twice-daily, dulaglutide demonstrated consistent superiority with differences of approximately 0.3-0.5% in HbA1c reduction. Comparisons with semaglutide suggested similar efficacy when comparing dose-equivalent formulations (semaglutide 0.5 mg vs dulaglutide 1.5 mg), though direct head-to-head data showed semaglutide superiority when switching from stable dulaglutide therapy.

Postprandial Glucose Control

Postprandial glucose control data were limited across the included studies. Most trials focused on HbA1c as the primary glycemic outcome without reporting specific postprandial measurements.

Two studies provided postprandial-specific data. In the AWARD-1 trial comparing dulaglutide to exenatide, dulaglutide 1.5 mg and 0.75 mg showed greater reductions in premeal and postprandial glucose levels compared to both placebo and exenatide. However, for 2-hour postprandial glucose excursions, exenatide demonstrated a greater reduction compared to dulaglutide. Meal-specific analyses revealed dulaglutide 1.5 mg and 0.75 mg achieved greater postprandial glucose reductions at midday and evening meals compared to exenatide.

The Omachi et al. prospective study assessed glucose variability using continuous glucose monitoring. Semaglutide 0.5 mg reduced postprandial hyperglycemia across all meals more effectively than dulaglutide 0.75 mg. Multiple glucose variability metrics favored semaglutide: standard deviation (SD) improved with p=0.005, mean amplitude of glycemic excursions (MAGE) with p=0.013, coefficient of variation (%CV) with p=0.038, time above range (TAR) with p=0.039, and time in range (TIR) with p=0.031. The study concluded that semaglutide improved glucose variability more efficiently than dulaglutide by reducing postprandial hyperglycemia.

Synthesis

The comparative efficacy of dulaglutide versus other GLP-1 receptor agonists shows a hierarchy influenced by multiple factors including dose, comparator choice, and study population characteristics.

Dulaglutide versus Liraglutide: The apparent contradiction between non-inferiority in the AWARD-6 trial and superiority in the Ye meta-analysis can be reconciled by study design differences. The AWARD-6 trial was a single RCT designed to demonstrate non-inferiority with a 0.4% margin, finding a small numerical difference of -0.06% favoring dulaglutide that fell within this margin. The meta-analysis pooled data from both RCTs and observational studies, potentially capturing real-world effectiveness differences not evident in controlled trial conditions. The meta-analysis advantage of -0.17% to -0.22% for dulaglutide, while statistically significant, remains clinically modest and within the bounds suggested by the AWARD-6 confidence intervals. Both findings may be correct: dulaglutide is non-inferior in head-to-head RCTs, with possible small superiority in broader clinical practice, though this advantage is offset by inferior weight loss.

Dulaglutide versus Exenatide: The consistent superiority of dulaglutide over exenatide twice-daily reflects both pharmacokinetic differences and dosing frequency. Weekly GLP-1 agonists maintain more stable drug levels than twice-daily formulations. The magnitude of benefit (approximately 0.4-0.6% greater HbA1c reduction) was consistent across independent studies, suggesting a robust pharmacological advantage. Interestingly, exenatide showed greater 2-hour postprandial glucose excursion reduction despite inferior overall glycemic control, consistent with its rapid-acting pharmacokinetic profile targeting acute postprandial responses.

Dulaglutide versus Semaglutide: The relationship between dulaglutide and semaglutide depends critically on dose comparison and patient context. When comparing commercially available doses (semaglutide 0.5 mg vs dulaglutide 1.5 mg), SUSTAIN 7 showed similar glycemic efficacy. However, the Omachi study found semaglutide superior when initiated in patients already receiving stable dulaglutide therapy. This discrepancy reflects different clinical scenarios: treatment-naïve comparisons versus therapeutic switching. In patients already adapted to dulaglutide, switching to semaglutide provided additional benefit, suggesting non-linear dose-response curves or receptor saturation effects with chronic GLP-1 agonist exposure. The improved glucose variability and postprandial control with semaglutide may also reflect its unique pharmacokinetic properties, including 94% albumin binding and extended half-life compared to dulaglutide.

Dose-Response Relationships: The consistent finding that dulaglutide 1.5 mg outperforms 0.75 mg suggests a dose-dependent effect, though the increment appears to follow diminishing returns rather than linear scaling. The 0.75 mg dose achieved approximately 85% of the 1.5 mg dose’s efficacy in AWARD-1, indicating approaching therapeutic ceiling effects.

Postprandial Control Trade-offs: The limited postprandial data suggest important mechanistic distinctions. Exenatide’s superior 2-hour glucose excursion control despite inferior overall HbA1c indicates rapid-acting GLP-1 agonists may preferentially target acute postprandial responses, while long-acting formulations provide more uniform 24-hour coverage. Semaglutide’s advantage in glucose variability metrics may reflect optimal balance between postprandial suppression and stable drug levels, positioning it between rapid-acting exenatide and intermediate-acting dulaglutide in the pharmacokinetic spectrum.