Trial summary

SUSTAIN 7: Ozempic vs Trulicity in type 2 diabetes

By David Chen·Editor

The trial in the population STEP 1 excluded, against a comparator that is not placebo: dulaglutide, the drug sold as Trulicity, against the semaglutide sold as Ozempic. It is also the clearest illustration of why one drug produces two very different weight figures depending on who is taking it.

Participants

1,201 randomized

Duration

40 weeks

Comparator

Dulaglutide at 0.75 mg and 1.5 mg once weekly

Published

The Lancet Diabetes & Endocrinology, 2018

Registration

NCT02648204

PubMed

PMID 29397376

Why this trial is here

STEP 1 and STEP 4 both excluded diabetes, so neither says anything about a reader who has it. SUSTAIN 7 is the trial that does — and it is a different kind of trial in two ways that change how its numbers should be read. Its primary endpoint is blood sugar rather than weight, and its comparator is another GLP-1 drug rather than placebo, so every figure below is a difference between two active treatments.

Who was in the trial

Adults aged 18 or older with type 2 diabetes inadequately controlled on metformin monotherapy, with HbA1c between 7.0% and 10.5%.

How it was run

Open-label, parallel-group, phase 3b trial at 194 sites in 16 countries. Patients were randomly assigned 1:1:1:1 to once-weekly semaglutide 0.5 mg, dulaglutide 0.75 mg, semaglutide 1.0 mg or dulaglutide 1.5 mg.

Change from baseline in percentage HbA1c at week 40; the confirmatory secondary endpoint was change in bodyweight.

It was open-label — everyone knew which drug they were receiving — and it was powered for HbA1c non-inferiority with a 0.4% margin and for bodyweight superiority. The four arms pair the drugs at two dose levels each, which is why the results come in matched pairs rather than as a single number.

What it found

On the primary endpoint, HbA1c fell by 1.8 percentage points on semaglutide 1.0 mg against 1.4 on dulaglutide 1.5 mg, and by 1.5 against 1.1 on the lower pair — estimated treatment differences of -0.41 and -0.40 percentage points, both P<0.0001.

On weight, the higher pair separated by 3.55 kg (-6.5 kg against -3.0 kg) and the lower pair by 2.26 kg (-4.6 kg against -2.3 kg), both P<0.0001. Gastrointestinal disorders were the most frequently reported adverse event in every arm — 43% and 44% on the two semaglutide doses, 33% and 48% on the two dulaglutide doses — and the most common reason for discontinuing either drug.

Why the weight figures are smaller

A reader moving between this page and STEP 1 will notice that 6.5 kg is a long way from 15.3 kg, and the gap is not a contradiction. Three things differ at once: the dose is 1.0 mg here against 2.4 mg there, the trial ran 40 weeks against 68, and weight loss on a GLP-1 is consistently smaller in people with type 2 diabetes than in people without it. Comparing the headline numbers directly compares three differences at the same time and attributes all of them to the drug.

Reading this alongside the price index

A seller listing a single price rarely says which of these two populations its figure is meant for, and the dose it ships may be neither trial’s. Every price on our index is restated per calendar month so that part is at least comparable, and what each dose costs shows where a seller’s price does and does not move with the milligrams.