What Is AZD6234 (Lenbelintide)?

1. What is AZD6234, and why is it called lenbelintide now?

AZD6234 came out of AstraZeneca’s own research and entered human testing in September 2022, when a single-ascending-dose study began in healthy adults with overweight or obesity (NCT05511025). At a November 2024 investor event, AstraZeneca presented it as a “selective amylin agonist” for once-weekly injection, and listed three intended uses: weight loss that spares lean mass, a replacement option for people who cannot tolerate incretin drugs, and a partner for its GLP-1/glucagon drug AZD9550 (AstraZeneca investor presentation, 2024).

In 2026 the drug picked up a generic name. On AstraZeneca’s third-quarter earnings call on October 30, 2026, R&D head Sharon Barr said the company had “dosed the first patients in three phase III trials for lenbelintide, formerly known as AZD6234” (Q3 2026 call transcript). AstraZeneca’s pipeline, dated October 30, 2026, lists lenbelintide (AZD6234) as a selective amylin receptor agonist in Phase III for chronic weight management, marked “New to Phase III” (AstraZeneca pipeline). This page keeps the AZD6234 name in its address because that is the name most trial records and papers still use.

2. How does AZD6234 work?

Amylin receptors are built from the calcitonin receptor paired with a helper protein called a RAMP (receptor activity-modifying protein). Different pairings make different amylin receptor subtypes. Long-acting amylin drugs fall into two groups (Alhazmi and le Roux, 2026):

• DACRAs (dual amylin and calcitonin receptor agonists) activate both the amylin receptors and the bare calcitonin receptor. Cagrilintide, petrelintide and Pfizer’s MET-233i belong here.
• SARAs (selective amylin receptor agonists) focus on the amylin receptors. AZD6234 and Lilly’s eloralintide belong here. The 2026 review lists AZD6234’s main target as the amylin 3 receptor.

The reasoning behind selectivity is that the calcitonin receptor is not needed for amylin’s appetite effects, so leaving it out might improve tolerability. The same review cautions that “it remains unclear whether differences in receptor pharmacology would manifest as a meaningful difference in weight loss efficacy,” because the trials differ too much to compare (Alhazmi and le Roux, 2026).

What the animal studies showed

AstraZeneca’s preclinical work emphasizes body composition. In a 15-day study in obese rats, AZD6234 produced dose-dependent weight loss that the company described as driven by fat loss “with lean mass preserved” (AstraZeneca investor presentation, 2024).

A 2025 abstract from AstraZeneca scientists then compared AZD6234 with semaglutide in diet-induced obese rats over 28 days, with doses chosen to give similar weight loss (Geoghegan et al., 2025):

Food intake fell about 20% with either drug and 41% with both. These are rat results reported by the developer in a conference abstract. Rats keep growing as adults, which is why the vehicle group gained lean mass, so “preserved lean mass” in a rat does not translate directly into a human claim. No human body-composition data for AZD6234 have been released.

3. What did the Phase 1 trials show?

The first-in-human study (NCT05511025) enrolled 54 participants and tested single doses under the skin and into a vein, including a Japanese cohort. AstraZeneca’s 2024 summary of the results, first presented at ObesityWeek 2024, reported (AstraZeneca investor presentation, 2024):

• Single doses of 0.3, 0.9, 1.5, 2.7 and 4.2 mg under the skin.
• After one 2.7 mg dose, mean weight loss of 1.7% in the global cohort and 3.8% in the Japanese cohort.
• “No safety concerns at doses up to 4.2mg.”
• 2.7 mg “deemed maximum tolerable single dose,” with mild nausea and vomiting at that level; nausea and vomiting rose with peak drug concentration.
• Pharmacokinetics that support once-weekly dosing.

The 2026 Diabetes, Obesity and Metabolism review summarizes the same study as showing dose-proportional pharmacokinetics, a terminal half-life of about 4 days, and the largest mean weight loss of 3.8% by day 5 after the 2.7 mg dose. It lists rates of 32.1% nausea and 17.9% vomiting, with gastrointestinal effects including decreased appetite, constipation and diarrhea (Alhazmi and le Roux, 2026). Note that the 3.8% figure applies to the Japanese cohort; the global cohort lost less.

A second Phase 1 study tested repeated doses in 104 people with overweight or obesity, including Japanese cohorts, and was completed in early 2026 (NCT06132841). Its results have not been published. A completed study in 24 people tested how kidney impairment affects drug levels (NCT06845813), and a 2026 review of long-acting amylin peptides lists AZD6234 among the newer analogs that “have shown strong efficacy as monotherapy in clinical trials” (Peptides review, 2026).

4. What Phase 2 trials have been run?

AstraZeneca ran three Phase 2 trials of AZD6234, each answering a different question. All three are listed as completed, and none has posted results on the registry as of November 8, 2026.

An earlier Phase 1/2 study, CONTEMPO, also included a 24-week part combining AZD9550 and AZD6234 in people with type 2 diabetes; it is active but no longer recruiting (NCT06151964).

The Phase 2 results have not been released. On the October 30, 2026 call, Barr said: “We look forward to sharing the phase II results for lenbelintide and AZD9550,” both alone and in combination, at an upcoming medical conference (Q3 2026 call transcript). AstraZeneca started Phase 3 before publishing them, which suggests the company was satisfied with what it saw, but the numbers themselves are not public. Any weight-loss figure for APRICUS that circulates before that presentation should be treated as unverified.

5. What are the combination plans?

AstraZeneca has described three ways to use AZD6234 (AstraZeneca investor presentation, 2024):

1. Instead of a GLP-1 drug, for people who cannot tolerate incretin medicines.
2. On top of an existing GLP-1 drug, to add weight loss.
3. With AZD9550, a once-weekly GLP-1 and glucagon dual agonist, giving a “triple mechanism” aimed at maximum weight loss.

The third route is the most ambitious. AZD9550 activates the GLP-1 receptor (appetite and blood sugar) and the glucagon receptor (energy expenditure and liver fat), in the same class as survodutide and mazdutide. Adding a selective amylin agonist would combine three hormone signals. AstraZeneca’s pipeline lists “AZD9550 + AZD6234” in Phase II for obesity (AstraZeneca pipeline), and a study comparing different under-the-skin formulations of the two drugs was registered to start on November 9, 2026, a step that usually precedes a combined product (NCT07911514).

The best evidence that amylin plus GLP-1 works in people comes from another company. In Novo Nordisk’s REDEFINE 1 trial, weekly cagrilintide plus semaglutide produced a mean body-weight change of −20.4% at 68 weeks, against −3.0% with placebo, in 3,417 adults without diabetes (Garvey et al., NEJM 2025). Whether a selective amylin agonist adds as much, or tolerates better, is exactly what ASCEND and SELENE 3 are designed to show. The CagriSema guide covers that combination.

6. What is the Phase 3 SELENE program?

AstraZeneca registered four Phase 3 trials, all with weekly injections under the skin. Statuses below were checked on ClinicalTrials.gov on November 8, 2026.

The registry does not name the Phase 3 doses. Sizes for trials still enrolling are estimates. The three SELENE trials match the “three phase III trials” AstraZeneca said it had started dosing (Q3 2026 call transcript).

There is no lenbelintide filing or approval date. With 68-week trials due to complete in August 2028, any application would follow after that.

7. How does AZD6234 relate to GLP-1 therapy?

For people already on semaglutide or tirzepatide, AZD6234 is notable because two of its trials are built around them.

Add-on, not just alternative. ARAY enrolled people with type 2 diabetes already on a stable GLP-1 drug, and SELENE 3 enrolls people on a stable incretin-based weight-management dose, with placebo as the comparison (ARAY; SELENE 3). If SELENE 3 succeeds, it would be direct evidence on adding an amylin agonist for people who have plateaued on a GLP-1 drug. Until then, that use is unproven.

Overlapping side effects. Both amylin and GLP-1 drugs slow stomach emptying and cause nausea and vomiting, most often at the start and during dose increases. In AZD6234’s single-dose study, nausea and vomiting rose with drug exposure (AstraZeneca investor presentation, 2024). In REDEFINE 1, 79.6% of people on the amylin plus GLP-1 combination had gastrointestinal events, against 39.9% on placebo (Garvey et al., 2025). Stacking two drugs that slow digestion is the main tolerability question.

Oral medicines. Because slower stomach emptying can change how pills are absorbed, AstraZeneca is running a study of whether AZD6234, AZD9550 or both alter levels of a combined oral contraceptive pill (NCT07013643). Results are not yet available.

Low blood sugar with insulin. Amylin drugs lower post-meal glucose by slowing its arrival from the gut, which can make injected insulin overshoot. The pramlintide label carries a boxed warning that use with insulin “increases the risk of severe hypoglycemia, particularly in patients with type 1 diabetes” (Symlin label). The AZD6234 trials excluded people using insulin (ARAY; SELENE 3), so how it behaves with insulin is not known.

Muscle. GLP-1 weight loss includes some lean mass, covered in GLP-1 and muscle loss. AstraZeneca’s rat data suggest AZD6234 removes mostly fat, but the same abstract found the combination with semaglutide still lost some lean mass (Geoghegan et al., 2025). Human data will have to settle it.

8. How does AZD6234 compare with other amylin drugs?

Receptor groupings follow the 2026 DOM review (Alhazmi and le Roux, 2026); stages for the other drugs come from their linked guides. AstraZeneca is unusual among large drugmakers in having taken a selective amylin agonist into Phase 3 without first publishing Phase 2 efficacy numbers. The public evidence for AZD6234 in people is still a single-dose study, so comparisons of how well it works against other amylin drugs are not yet possible.

For a personal record, an investigational drug is logged like any other: product, date, dose and injection site, with the interval set to weekly. How GLP-1 tracking works covers what to record. The next real milestone is AstraZeneca’s Phase 2 presentation, followed by SELENE results expected after August 2028.

9. AZD6234 FAQ

• Is AZD6234 the same as lenbelintide?

  Yes. AZD6234 is AstraZeneca's code. On its October 30, 2026 earnings call, AstraZeneca referred to lenbelintide, formerly known as AZD6234, and the Phase 3 trial records list the study drug as lenbelintide.

• What kind of drug is AZD6234?

  It is a long-acting peptide that activates amylin receptors, taken as a weekly injection under the skin. AstraZeneca calls it a selective amylin receptor agonist. Amylin is a hormone released with insulin after meals that slows stomach emptying and helps end a meal. AZD6234 is not a GLP-1 drug.

• How much weight loss does AZD6234 cause?

  Only single-dose human data are public. After one 2.7 mg dose, mean weight loss was 1.7% in the global cohort and 3.8% in a Japanese cohort, measured within days. The 36-week Phase 2b APRICUS trial has finished, but AstraZeneca had not released its results as of November 8, 2026 and said it would present them at an upcoming medical conference.

• Can AZD6234 be taken with semaglutide or tirzepatide?

  That is being tested, not established. The Phase 2 ARAY trial gave AZD6234 or placebo to adults with type 2 diabetes who were already on a stable GLP-1 drug, and the Phase 3 SELENE 3 trial adds lenbelintide to incretin-based medicines at weight-management doses. Results are not public, so no one should combine these drugs outside a trial.

• What is the AZD6234 and AZD9550 combination?

  AZD9550 is AstraZeneca's weekly GLP-1 and glucagon dual agonist. Together with AZD6234 it would hit three hormone pathways. The ASCEND Phase 2b trial tested seven dose pairings of the two drugs against each drug alone and placebo for 36 weeks in 377 adults. It finished in May 2026; results are pending.

• What are the side effects of AZD6234?

  In the single-dose study, nausea and vomiting were the main side effects and became more frequent at higher drug levels. A 2026 review summarized the rates in that study as 32.1% nausea and 17.9% vomiting. A 4.2 mg dose was tested without safety concerns, but 2.7 mg was the highest well-tolerated single starting dose.

• When will lenbelintide be available?

  There is no filing and no approval date. The SELENE Phase 3 trials started in August 2026 with 68-week primary endpoints and estimated primary completion in August 2028. A filing would come after those results, so availability is several years away at the earliest.

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