NCT05929066: what is the TRIUMPH-1 retatrutide trial?

What is NCT05929066?

NCT05929066 is the ClinicalTrials.gov registry number for TRIUMPH-1, an Eli Lilly and Company Phase 3 trial of retatrutide, also called LY3437943, in adults with obesity or overweight and without type 2 diabetes. A registry number is a trial's public identifier. Phase 3 is a large late-stage research step. Randomised means chance assigned the study groups. Double-blind means participants and investigators did not know each person's group. ClinicalTrials.gov NCT05929066 records 2335 participants enrolled across 134 locations and lists the trial as COMPLETED.

ClinicalTrials.gov NCT05929066 carries three filing identifiers: 18557, J1I-MC-GZBJ, and EU 2023-503657-35-00. One belongs to the sponsor's records, one is the master protocol code, and one belongs to the European Union filing system. They point to the same trial through different desks.

ClinicalTrials.gov NCT05929066 was first posted in 2023 and shows its last update posted on 21 August 2026. The public number stays still while dates, enrolment, status, and other fields can move around it. That fixed label is what lets readers follow a changing record without losing the file.

Evidence limits

What has NCT05929066 not shown?

Eli Lilly and Company later discussed TRIUMPH-1 at a conference, but that sponsor communication is not a registry results table. The sponsor-remarks section below keeps the company announcement separate from what ClinicalTrials.gov NCT05929066 has actually posted.

Published obesity evidence for retatrutide comes from earlier, smaller work. The Phase 2 trial that came before it followed 338 adults for 48 weeks (Jastreboff et al., NEJM, 2023). That study gives background for the later programme. It is not part of TRIUMPH-1, and none of its findings fills this registry's empty results section.

Is the TRIUMPH-1 trial completed?

Yes. ClinicalTrials.gov NCT05929066 lists TRIUMPH-1 as COMPLETED. The registry gives an actual study start of 10 July 2023, an actual primary completion of 6 April 2026, and an actual study completion of 30 April 2026. Primary completion marks the last measurement for the main outcomes. Study completion marks the last participant finishing the study altogether. The two dates therefore close different parts of the same record. ClinicalTrials.gov NCT05929066 shows the latest registry update for this entry posted on 21 August 2026.

The status field and the results section do different jobs. One tells readers whether study activity is still under way. The other is where outcome tables would appear. ClinicalTrials.gov NCT05929066 closes the first question with COMPLETED and leaves the second blank with no results posted.

TRIUMPH-1 is one stop in a longer sequence of retatrutide research. The sibling guide to how long retatrutide has been studied follows that wider timeline. This page stays with the dates attached to this record.

Who took part in TRIUMPH-1?

TRIUMPH-1 enrolled 2335 adults across 134 locations (ClinicalTrials.gov NCT05929066). Entry required a body mass index of at least 30 kg/m², or at least 27 kg/m² with hypertension, dyslipidemia, obstructive sleep apnoea, or cardiovascular disease. Body mass index is a weight-for-height screening measure. Hypertension means high blood pressure. Dyslipidemia means unhealthy blood-fat levels. Obstructive sleep apnoea means repeated airway blockage during sleep. ClinicalTrials.gov NCT05929066 also required one recorded unsuccessful dietary weight-loss effort and excluded adults with diabetes mellitus from taking part.

Entry rules draw a border around every future finding. The people inside this record met a written set of health and weight criteria, while people outside it did not. Any result that later appears will belong first to that defined group, not automatically to every adult with obesity or overweight.

TRIUMPH-1 and its sibling trial enrolled different groups. The nearby TRIUMPH-3 registry record covers a different population. ClinicalTrials.gov NCT05882045 enrolled adults who already had cardiovascular disease, while ClinicalTrials.gov NCT05929066 excluded type 2 diabetes and did not require heart or artery disease. The shared compound name does not erase that difference.

What did TRIUMPH-1 measure?

ClinicalTrials.gov NCT05929066 lists four planned primary outcome measures for TRIUMPH-1: percent change from baseline in body weight at Week 80; apnoea–hypopnoea index from baseline to Week 80 in the sleep-apnoea sub-study; a WOMAC pain measure from baseline to Week 80 in the knee-osteoarthritis sub-study; and body-weight percent change from baseline at Week 104 for an extension subset. The apnoea–hypopnoea index counts breathing interruptions per hour of recorded sleep in that group. WOMAC is a questionnaire about joint pain and function.

TRIUMPH-1's four listed outcomes are planned measures on ClinicalTrials.gov NCT05929066, not findings. The registry does not post a value for any of them. A question written into a protocol shows what researchers intended to count. Only a results table can show what that count became.

TRIUMPH-1 reaches across body weight, sleep breathing, and knee symptoms under one record. That range is not an accident or three unrelated lists. It follows the umbrella design of the master protocol, which the next section opens up.

What is a master protocol, and what are TRIUMPH-1's nested sub-studies?

A master protocol is one umbrella design that runs several related sub-studies under a shared record. TRIUMPH-1 uses master protocol J1I-MC-GZBJ, with J1I-MC-GOA1 nested beneath it for knee osteoarthritis and J1I-MC-GSA1 for obstructive sleep apnoea (ClinicalTrials.gov NCT05929066). This structure lets one trial infrastructure and one registry number hold several linked research questions. The main protocol asks about body weight, while the nested studies add condition-specific measures. The names are separate, but the public filing joins them under NCT05929066 on the same site.

ClinicalTrials.gov NCT05929066 does not publish the number of participants in either nested sub-study. The registry's actual enrolment of 2335 belongs to the whole record, not to a visible sum that can be split between the master study and its two baskets. The missing totals stay missing here.

NCT05929066 is the paperwork puzzle from the opening. A short registry label can look like one small item in a search list. Open the record, and the label turns out to cover a main protocol, two indication sub-studies, and several planned outcomes moving through one shared structure.

Did Eli Lilly report TRIUMPH-1 results at ADA 2026?

Eli Lilly and Company presented topline TRIUMPH-1 remarks at the American Diabetes Association's 86th Scientific Sessions on 6 June 2026, but that press release was sponsor communication, not posted registry results (Eli Lilly press release, PR Newswire, 6 June 2026). ClinicalTrials.gov NCT05929066 still showed no results posted as of 21 August 2026. The registry records 2335 enrolled participants (ClinicalTrials.gov NCT05929066). The same company announcement states 2339 randomised participants (PR Newswire, 6 June 2026). The two documents give two figures, and this page does not reconcile them.

The ClinicalTrials.gov field is information the sponsor posts to the US trial registry. A press release is a company announcement written for a conference audience. Neither document is a peer-reviewed paper. The company announcement is also not a National Library of Medicine results table, so its remarks do not fill the blank section on ClinicalTrials.gov NCT05929066.

The NCT05929066 page withholds efficacy figures from the company announcement. Without posted outcome tables or a peer-reviewed TRIUMPH-1 paper, readers cannot check those figures against the full methods and results. The honest record is therefore the source contrast itself: what the sponsor said, what the registry shows, and what remains unpublished.

Does a completed trial say anything about research material?

No. A registry record describes a study of an investigational compound run under a protocol. ClinicalTrials.gov NCT05929066 has published no findings, and the entry says nothing about any physical material supplied for laboratory work. Retatrutide had no national approval anywhere as of 2026. Research material is not a medicine, not a substitute for one, and not for human or animal use. A trial identifier cannot establish the identity, purity, or content of a supplied material. Those questions belong to records tied to the physical lot.

A certificate of analysis is the paperwork that speaks about one specific lot. The catalogue entry for retatrutide reference material places that lot documentation beside availability. A registry identifier copied from ClinicalTrials.gov cannot replace the certificate, because the two records describe different things.