Kailera Therapeutics presented full Phase 1 multiple-dose data for KAI-4729 at EASD 2026 on October 1. KAI-4729 is a once-weekly GLP-1/GIP/glucagon "triple G" agonist built on the same receptor profile as retatrutide. At the 12 mg dose, participants lost a mean 16.0% of body weight in 12 weeks, and liver fat fell 67.3%.
The weight number made headlines when it first surfaced in May. What's new at EASD is the comparison arm. Kailera's own dual agonist, ribupatide, slightly out-lost the triple agonist on weight in the same trial, 16.7% versus 16.0%. But it cut liver fat by only 38.4%. So the glucagon arm is earning its place on the liver, not on the scale, at least at 12 weeks.
Research-context information only. Compounds discussed below are investigational drugs and research peptides; most are not approved by the FDA. Doses and outcomes reported come from published clinical trials and company disclosures. Possession or use of investigational drugs outside an authorized clinical trial may be illegal in your jurisdiction. This article reports what has been documented, not what should be done. Consult a licensed physician for personal medical decisions.
What Kailera Reported at EASD
The data comes from a randomized, double-blind, placebo-controlled Phase 1 trial run by Jiangsu Hengrui Pharmaceuticals in China. Hengrui discovered the molecule (coded HRS-4729 there), and Kailera holds rights outside China. Kailera's October 1 release lists the following week-12 results from the multiple-ascending-dose (MAD) portion:
| Arm (once weekly) | Participants | Mean weight loss, wk 12 | Mean liver fat reduction |
|---|---|---|---|
| KAI-4729, escalated to 12 mg | ~10 | 16.0% | 67.3% |
| Ribupatide 4 mg (GLP-1/GIP control) | ~10 | 16.7% | 38.4% |
| Placebo | n/a | 5.4% | n/a |
Source: Kailera Therapeutics EASD 2026 release, October 1, 2026. Liver fat measured by MRI proton density fat fraction (MRI-PDFF).
The trial tested 1 mg, 4 mg, 8 mg, and 12 mg weekly doses. Kailera reported dose-dependent liver fat reductions. It described the safety profile as consistent with GLP-1-based treatments, with most treatment-emergent adverse events mild to moderate and gastrointestinal.
Two caveats travel with every number in that table. First, the arms hold about 10 people each. One participant's response can move the mean by a full percentage point. Second, a 5.4% placebo loss at 12 weeks is unusually high, which suggests heavy lifestyle co-intervention or a small-sample artifact. The placebo-adjusted figure, roughly 10-11 points, is the more honest read.
The Retatrutide Comparison Everyone Is Making
The reason KAI-4729 is getting attention is the benchmark. When the 16% topline first appeared in May, BioPharma Dive reported that retatrutide lost under 10% at the 12-week mark in its own early trials. T.D. Cowen analyst Yaron Werber called KAI-4729's result "a step up in potency vs retatrutide" and "a highly encouraging early" signal.
That framing needs context before it means anything.
Retatrutide's data is deep. KAI-4729's is a snapshot. Retatrutide's Phase 2 trial (Jastreboff et al., NEJM 2023, 338 participants) reported 24.2% mean weight loss at 48 weeks on 12 mg. Lilly's TRIUMPH-1 Phase 3 top-line, announced May 2026, reported 28.3% at 80 weeks. KAI-4729 has 12 weeks in about 10 people.
Faster early weight loss can be a titration choice. How quickly a drug escalates to its top dose drives how much weight comes off by week 12. A Phase 1 MAD study built to reach 12 mg fast will front-load results compared with a Phase 2 design that titrates slowly for tolerability. It says little about where the curve plateaus.
On liver fat, retatrutide already set a high bar. In the MASLD substudy of retatrutide's Phase 2 trial (Sanyal et al., Nature Medicine 2024), the 12 mg dose cut liver fat by roughly 82% at 24 weeks. Most participants on the higher doses reached normal liver fat levels. KAI-4729's 67.3% at 12 weeks is strong, but it is a shorter window. Neither result is directly comparable to the other.
The fair summary: the trial results are consistent with triple G pharmacology. KAI-4729 shows strong early weight loss and a clear liver signal beyond what the dual agonist produced. Whether it beats retatrutide is a question for Phase 2, not Phase 1.
Why the Ribupatide Arm Is the Real Finding
Including ribupatide as an active control was a deliberate choice. Ribupatide (KAI-9531) is Kailera's GLP-1/GIP dual agonist, the same receptor pair as tirzepatide. It is already in global Phase 3, and Kailera announced on September 30 that enrollment in the KaiNETIC Phase 3 program is complete. Our ribupatide Phase 3 breakdown covers that program.
Running the triple agonist against the dual agonist isolates what glucagon adds. At 12 weeks, the answer from this small trial is:
- Weight: roughly nothing extra. 16.0% versus 16.7% is a statistical tie at this sample size.
- Liver fat: a lot extra. 67.3% versus 38.4%, nearly a 1.75x larger reduction.
That fits the biology. Glucagon receptor activation in the liver is reported in the published literature to increase fat oxidation and energy expenditure. It is the stated rationale for why glucagon-containing agonists like retatrutide and survodutide are being studied in MASH (fatty liver disease). The weight-loss advantage of glucagon agonism, where it shows up, has historically emerged over longer treatment periods.
It also explains Kailera's portfolio logic. Ribupatide is the near-term dual agonist in Phase 3. KAI-4729 is the longer-dated triple agonist that could be positioned for patients with significant liver fat, or as a next-generation follow-on.
Kailera's Development Timeline
Per Kailera's release and BioPharma Dive's reporting:
- Hengrui: advancing HRS-4729 in Phase 2 in China.
- Kailera: launching a Phase 1 trial outside China in 2026, with data expected in 2027.
- Funding: Kailera raised $625 million in its IPO and has said its cash runway extends through 2028.
On that schedule, a global Phase 3 for KAI-4729 would likely not start before 2028. Approval anywhere outside China would land near the end of the decade at the earliest. Obesity pipelines also see meaningful attrition between Phase 1 and approval.
