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Apraglutide

A once-weekly GLP-2 analogue engineered for extremely low clearance, developed to reduce intravenous feeding in short bowel syndrome. Its phase 3 trial met its primary endpoint, then the FDA asked for a second one after the sponsor discovered the trial had delivered less drug than intended.

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Last updated 26 citations
TL;DR

Apraglutide is an experimental once-a-week injection for short bowel syndrome, a condition where people have lost so much intestine that they need intravenous feeding to survive. It copies a natural gut hormone that makes the remaining bowel grow and absorb more. Its big trial worked, but the company then found the trial had given patients less drug than planned, and the FDA asked for another trial before approving it. It is not available to patients outside clinical studies.

What is Apraglutide?

Apraglutide is a synthetic analogue of glucagon-like peptide-2, the hormone the intestine releases after eating to keep its own lining growing and absorbing. People with short bowel syndrome have lost so much intestine — usually to surgery for Crohn's disease, mesenteric ischaemia or volvulus — that they cannot absorb enough fluid and nutrition by mouth, and depend on parenteral support delivered through a central line for hours each night. GLP-2 analogues work by pushing the remaining bowel to adapt: taller villi, thicker mucosa, slower transit, more absorption per centimetre. The first of them, teduglutide, has been approved since 2012 but requires a daily injection. Apraglutide was designed to be the once-weekly version, using amino acid substitutions that give it very high plasma protein binding and an elimination clearance roughly thirty-fold lower than teduglutide's in rats. It is not approved anywhere. Its phase 3 trial, STARS, met its primary endpoint in 2026, but the FDA has required a confirmatory trial first — and the sponsor disclosed that STARS delivered lower drug exposure than the protocol intended.

What Apraglutide Is Investigated For

Apraglutide's case rests on one global phase 3 trial and reads differently depending on which endpoint you look at. STARS randomised 163 patients 2:1 and hit its primary endpoint: weekly parenteral support volume fell 25.5% against 12.5% on placebo. It also hit the endpoint the molecule was designed for — patients with an end stoma and no colon, historically the group that responds least to GLP-2 therapy, improved by 25.6% against 7.8%. But at week 48, in the colon-in-continuity group, the proportions achieving at least one day a week off intravenous support were 51.8% on apraglutide and 44.4% on placebo, a gap that did not approach significance, and enteral autonomy was reached by 12.5% versus 7.4%. A 44% placebo response on days off support is a warning about how much of the improvement in these trials comes from the structured weaning protocol rather than the drug. The contrast with the uncontrolled data is even starker: a nine-patient open-label study measured a 52% fall in parenteral volume at 52 weeks, roughly double what the controlled trial produced. Everything else — the once-weekly schedule, the stoma advantage, the graft-versus-host disease programme — is reasonable but unsettled, and the drug cannot be prescribed for any of it.

Reducing parenteral support in short bowel syndrome with intestinal failure (phase 3, not approved)
Moderate70%
Patients with an end stoma and no colon, in whom teduglutide works less well
Moderate70%
Achieving enteral autonomy — coming off intravenous support entirely
Limited15%
Once-weekly rather than daily injection for a lifelong condition
Moderate70%
Gastrointestinal graft-versus-host disease (preclinical and early clinical)
Preliminary30%

History & Discovery

GLP-2 was identified in the 1980s as a second peptide cleaved from proglucagon alongside GLP-1, and its trophic effect on the intestine was recognised soon after. Translating it into a drug took two decades and a single, modest chemical idea: replacing the alanine at position 2 blocks cleavage by DPP-4, extending the half-life from minutes to a few hours. That molecule, teduglutide, was approved in 2012 and remains the reference treatment for short bowel syndrome with intestinal failure. Its limitation is also modest and relentless — a daily subcutaneous injection, for life, in patients who already spend their nights attached to an infusion pump. Apraglutide came out of Ferring Research Institute in San Diego as FE 203799, designed around a different goal: not merely resisting DPP-4 but minimising clearance altogether, through substitutions conferring very high plasma protein binding and slow absorption. The 2020 characterisation paper in the Journal of Pharmacology and Experimental Therapeutics laid out the result — a thirty-fold lower clearance than teduglutide in rats, a 159-minute elimination half-life, and greater intestinal growth at longer dosing intervals — and also claimed that the rival long-acting candidate glepaglutide was less potent and less selective at the receptor. Zealand Pharma, glepaglutide's developer, published a formal comment in the same journal disputing it, and a correction was issued alongside. The episode is a useful marker of how small and contested this field is. VectivBio, a Basel spin-out, took apraglutide through phase 1 and 2, and Ironwood Pharmaceuticals acquired VectivBio in 2023. The phase 3 STARS trial, which had been stratified by remnant anatomy specifically to test the stoma population that GLP-2 therapy has historically served least well, read out positive on its primary endpoint. Ironwood began a rolling new drug application in January 2025 and expected to complete it that year. In April 2025 the plan collapsed. A pharmacokinetic analysis conducted while preparing the application showed that the exposure and dose delivered in STARS had been lower than planned, because of how the dose was prepared and administered. After discussions with the FDA, Ironwood announced that a confirmatory phase 3 trial in parenteral-support-dependent patients would be required before approval; the company's shares fell by roughly a third and it engaged advisers to review strategic alternatives. STARS-2, a 24-week global randomised double-blind placebo-controlled trial with relative change in actual weekly parenteral support volume as its primary endpoint, began initiating sites in the second quarter of 2026, with an open-label extension, STARS Extend, running alongside. A drug that met its primary endpoint in a 163-patient international phase 3 trial is, five years later, still not approved anywhere — and the reason has nothing to do with whether it works.

How It Works

After a meal, the intestine releases a hormone called GLP-2 that tells its own lining to grow, slow down and absorb more. Native GLP-2 is destroyed within minutes, which is useless as a medicine. Apraglutide is a redesigned version that sticks tightly to blood proteins and is cleared very slowly, so one injection keeps the signal going for a week. In someone whose bowel has been largely removed, that sustained signal makes the remaining stretch thicker, taller-villied and slower, so more of what they eat and drink is actually absorbed — which in turn means fewer litres have to go in through a vein each night.

Native human GLP-2 is a 33-amino-acid peptide released from intestinal L cells alongside GLP-1 after nutrient intake. It binds the GLP-2 receptor, a class B G-protein-coupled receptor expressed on subepithelial myofibroblasts and enteric neurons rather than on enterocytes themselves, and acts indirectly through IGF-1, keratinocyte growth factor, VEGF and nitric oxide to increase crypt cell proliferation, reduce enterocyte apoptosis, lengthen villi, increase mucosal blood flow, slow gastric emptying and reduce gastric acid secretion. The net effect is more absorptive surface operating for longer on each meal. Its therapeutic problem is pharmacokinetic: cleavage by dipeptidyl peptidase-4 at the position-2 alanine plus rapid renal clearance gives native GLP-2 a half-life of minutes, which teduglutide addresses with a single Ala2Gly substitution — enough for a daily injection and no more. Apraglutide, developed as FE 203799, carries further substitutions selected to combine DPP-4 resistance with very high plasma protein binding and slow subcutaneous absorption. In the developers' comparative rat study, intravenous clearances were 25 mL/kg/min for native GLP-2, 9.9 for teduglutide, 2.8 for glepaglutide and 0.27 for apraglutide, with elimination half-lives of 6.4, 19, 16 and 159 minutes; the same profile was confirmed in monkey and minipig and translated into greater small intestinal growth in rats at less frequent dosing intervals. That paper also reported that apraglutide and teduglutide retain potency and selectivity at the GLP-2 receptor comparable to native hGLP-2 while glepaglutide was less potent and less selective — a claim contested in a formal comment published by scientists from Zealand Pharma, glepaglutide's developer, in the same journal. In humans, mean estimated clearance is 16.5 to 20.7 L/day with a volume of distribution of 55 to 105 litres, and pharmacodynamics are tracked with plasma citrulline, an amino acid produced almost exclusively by enterocytes and therefore a proxy for enterocyte mass. Weekly dosing produced dose-dependent citrulline elevation, with 5 mg giving the maximal response and the elevation persisting 10 to 17 days after the final injection. Severe renal impairment produced lower rather than higher exposure and required no dose reduction.

Evidence Snapshot

Overall Confidence58%

Human Clinical Evidence

Moderate, and complicated. One global phase 3 trial, STARS, randomised 163 patients 2:1 and met its primary endpoint of relative change in weekly parenteral support volume at 24 weeks, along with the stoma-subgroup and days-off-support secondary endpoints; the week-48 colon-in-continuity endpoints did not separate from placebo. Supporting data come from a placebo-controlled phase 2 trial, a 52-week open-label metabolic balance study in nine patients, and phase 1 studies in healthy volunteers and in renal and hepatic impairment. The FDA has required a confirmatory phase 3 trial, STARS-2, before it will consider approval, after the sponsor found that delivered exposure in STARS was below plan.

Animal / Preclinical

Solid and directly predictive. Comparative pharmacokinetics in rat, monkey and minipig established the clearance advantage, mouse studies mapped segment-specific and time-dependent intestinal growth, and a neonatal piglet model of short bowel syndrome showed enhanced adaptation and linear intestinal growth. Separate work in mouse allogeneic transplantation supports the graft-versus-host disease hypothesis.

Mechanistic Rationale

Strong. GLP-2 receptor biology is well established, teduglutide has validated the target clinically since 2012, and the design rationale — that a longer-acting agonist should produce more intestinal growth at a less burdensome dosing interval — is supported by the comparative animal pharmacodynamics. What the mechanism cannot tell you is whether weekly beats daily in patients, which no head-to-head trial has tested.

Research Gaps & Open Questions

What the current literature has not yet settled about Apraglutide:

  • 01Whether apraglutide works at the dose that would actually be marketed. STARS met its primary endpoint at an exposure the sponsor subsequently found to be lower than planned, so efficacy, dose and safety all have to be re-established in STARS-2.
  • 02How much of the improvement in short bowel syndrome trials is the drug and how much is the weaning protocol. Placebo arms achieved a 12.5% reduction in parenteral volume at 24 weeks and 44.4% achieved a day off support at 48 weeks — figures large enough to dominate any underpowered comparison.
  • 03Whether reducing parenteral support changes outcomes that matter. No trial in this field has been powered for catheter-related bloodstream infection, intestinal failure-associated liver disease, transplantation or survival, so the entire class is approved on a surrogate.
  • 04How apraglutide compares with teduglutide and glepaglutide head-to-head. Only indirect network meta-analysis exists, and the one published direct comparison of receptor pharmacology was produced by one sponsor and disputed by another.
  • 05Whether weekly dosing genuinely improves adherence and quality of life enough to matter in a population already managing nightly infusions. It is the drug's main selling point and has never been tested against daily dosing in patients.
  • 06Long-term neoplasia risk under years of intestinal growth factor exposure, which is unquantified for the whole GLP-2 class and will require registry data rather than trials.
  • 07Whether the graft-versus-host disease indication is real. Mouse transplantation data and mechanistic reviews are encouraging, but no controlled human trial has reported.

Forms & Administration

Subcutaneous injection once weekly, in trial settings only. Doses in the published human studies have ranged from 1 to 10 mg weekly, with 5 mg producing the maximal citrulline response in healthy volunteers and weight-banded dosing used in the phase 3 programme. There is no marketed presentation, no brand name and no commercially available device, because the drug is not approved in any jurisdiction. The exposure shortfall the sponsor identified in STARS was attributed to how the dose was prepared and administered, which means the eventual commercial presentation — and the handling instructions that come with it — is itself part of what the confirmatory trial has to get right. Parenteral support is reduced on a protocol-defined schedule as absorption improves, so administration in practice is inseparable from a structured weaning plan supervised by an intestinal rehabilitation team.

Dosing & Protocols

The ranges below reflect protocols commonly discussed in the literature and by clinicians — not a prescription. Actual dosing for any individual should be determined by a qualified healthcare provider who knows the patient.

Typical Range

Investigational only. Published human studies used 1, 5 and 10 mg weekly in healthy volunteers, with 5 mg producing the maximal citrulline response, and weight-banded dosing in the phase 3 programme. No approved dose exists, and the sponsor's own analysis found that the exposure actually delivered in the phase 3 trial fell short of what the protocol intended.

Frequency

Once weekly by subcutaneous injection.

Timing Considerations

Time of day

Any consistent time on the chosen day of the week — the pharmacokinetics make timing irrelevant

Relative to meals

No relationship to food established

Relative to exercise

Not tied to exercise timing.

Citrulline and parenteral support volumes are assessed on protocol schedules relative to the injection day; in trials, support reduction decisions were keyed to repeated 48-hour fluid balance measurements rather than to single readings.

Cycle Length

Indefinite. Short bowel syndrome does not resolve, and preclinical work indicates that the intestinal growth produced by long-acting GLP-2 analogues is not fully durable once treatment stops, so therapy is continuous rather than cyclical.

Protocol Notes

There is no legitimate way to take apraglutide outside a clinical trial, and no self-directed dosing guidance to give. What is worth understanding is that dosing in short bowel syndrome is never just about the injection. Parenteral support is reduced on a structured schedule as absorption improves — in the trials, by protocol-defined algorithms keyed to 48-hour fluid balances — and that weaning process is where most of the clinical work and most of the risk sits. Reduce too slowly and the measured benefit disappears; reduce too fast and the patient becomes dehydrated or, as absorption improves further, fluid-overloaded. The placebo arms in these trials achieve substantial reductions on the weaning protocol alone, which is both a methodological headache and a clinical fact: structured management by an intestinal rehabilitation team is itself an intervention. One cautionary detail deserves emphasis for anyone reading the trial literature: the STARS exposure shortfall was attributed to how the dose was prepared and administered, not to the molecule, which is a reminder that for a weekly injectable the handling instructions are part of the drug.

Apraglutide is an investigational drug not approved by the FDA, EMA or any other regulator. It is not available by prescription, from compounding pharmacies or from peptide suppliers, and anything sold under its name is not the clinical product. Short bowel syndrome with intestinal failure is a life-threatening condition managed in specialist centres; GLP-2 therapy, parenteral support weaning and central line care all require that setting.

Timeline of Effects

Onset

Earlier than the clinical endpoints suggest. Plasma citrulline, the marker of enterocyte mass, rises dose-dependently within the first weeks of weekly dosing. In the open-label metabolic balance study, faecal output had fallen by 253 g a day at four weeks, before measurable changes in absorption or bowel length. The clinically meaningful endpoint — litres of intravenous support avoided — moves more slowly because it is gated by how fast the weaning protocol allows support to be reduced.

Peak Effect

Structural and functional changes continue accruing over the better part of a year. The 52-week study found absorption improvements and intestinal lengthening at 48 weeks that were not present at 4, and the phase 3 trial's week-48 results in colon-in-continuity patients showed larger proportions off support than week 24 in both arms. Whether that reflects continuing drug effect or continuing weaning is precisely what the placebo arm's 44.4% makes impossible to disentangle.

After Discontinuation

Regression. Preclinical work on long-acting GLP-2 analogues found that linear small-intestinal growth is not fully durable after treatment stops, which matches the clinical understanding of the class: the adapted mucosa depends on continued receptor stimulation, and parenteral support requirements rise again. Citrulline elevation persisted 10 to 17 days after the last dose in healthy volunteers, giving some sense of the tail, but the class is not thought to produce permanent remodelling.

Monitoring & Measurement

Bloodwork & Labs

  • •Plasma citrulline — the enterocyte mass marker used throughout the apraglutide programme, rising dose-dependently and persisting 10 to 17 days after a dose
  • •Serum electrolytes, urea, creatinine and magnesium, measured repeatedly during parenteral support weaning, where both dehydration and overload are live risks
  • •48-hour fluid balance studies, which is how the trials actually decided whether support could be reduced — urine volume exceeding baseline by more than 10% triggered a reduction
  • •Liver function tests and bilirubin, because intestinal failure-associated liver disease is the main competing threat in this population
  • •Fat-soluble vitamins, trace elements and B12, which remain deficient in short bowel syndrome regardless of GLP-2 therapy

Functional & Performance Tests

  • •Stoma or faecal output volume, measured daily during dose initiation and weaning
  • •Body weight and clinical volume status, which together detect the shift from under- to over-replacement faster than any laboratory value
  • •Colonoscopy before initiation and periodically thereafter, the class-standard surveillance for an intestinal growth factor
  • •Cross-sectional imaging of bowel calibre and wall thickness, used as endpoints in the metabolic balance study and increasingly as a response measure
  • •Days per week free of parenteral support, which is the outcome patients care about and the endpoint most sensitive to the weaning protocol rather than the drug

When to Test

In trial protocols, baseline metabolic balance and imaging before the first dose, fluid balance measured monthly over 48-hour periods to drive support reduction, and formal reassessment at 24 and 48 weeks. Colonoscopy before starting and at intervals thereafter. Outside a trial there is no schedule, because there is no approved use.

Interpretation & Notes

Monitoring in short bowel syndrome is unusual in that the measurement drives the therapy rather than merely checking it. The endpoint that defines success — litres of intravenous support avoided — is only reached by deliberately reducing support, and reducing support is only safe if fluid balance is measured repeatedly, which is why the trials used monthly 48-hour balance studies rather than clinic impressions. That design has a consequence anyone reading the data needs to hold onto: a protocol that systematically probes how little support a patient can manage on will produce substantial reductions in a placebo arm, and in the phase 3 trial it produced 12.5% at 24 weeks and 44.4% achieving a day off support at 48 weeks in the colon-in-continuity group. Citrulline is the one marker that reflects the drug rather than the protocol, which is why it has carried so much weight in dose selection. And the single most important thing to watch clinically is the transition point — the moment when improving absorption plus unchanged infusion volume tips a patient from chronically dry to fluid-overloaded, which can happen within days.

Common Questions

How is apraglutide different from teduglutide?

Mainly in how long it lasts. Teduglutide is a minimally modified GLP-2 — a single substitution protecting it from the enzyme DPP-4 — and must be injected every day. Apraglutide carries further substitutions chosen to produce very high plasma protein binding and slower absorption, which together give it dramatically lower clearance. In the head-to-head rat pharmacokinetic comparison published by apraglutide's developers, intravenous clearances were 25 mL/kg/min for native human GLP-2, 9.9 for teduglutide, 2.8 for glepaglutide and 0.27 for apraglutide, with elimination half-lives of 6.4, 19, 16 and 159 minutes respectively. In humans, a single weekly 5 mg dose produced the maximal response on plasma citrulline, a marker of enterocyte mass, and that elevation persisted for 10 to 17 days after the last injection. The practical consequence for a patient facing a lifelong daily injection is obvious; the practical consequence for the trial was that dose preparation and administration turned out to matter more than anyone expected.

Why did the FDA ask for a second phase 3 trial if the first one succeeded?

Because of a dosing problem the sponsor found itself. Ironwood began a rolling new drug application in January 2025. While preparing it, a pharmacokinetic analysis showed that the drug exposure and dose actually delivered in STARS were lower than planned, as a consequence of how the dose was prepared and administered. In April 2025 the company announced that after discussions the FDA had indicated a confirmatory phase 3 trial in parenteral-support-dependent patients would be needed before approval, with the STARS data remaining part of the eventual submission. The confirmatory trial, STARS-2, is a 24-week global randomised double-blind placebo-controlled study with relative change in actual weekly parenteral support volume as its primary endpoint, with sites beginning to open from the second quarter of 2026. Read charitably, this is a trial that demonstrated efficacy at an unintentionally low exposure. Read strictly, it is a trial whose delivered dose is not the dose anyone intends to market.

Why does having a stoma matter so much in these trials?

Because the colon does a large part of the work. GLP-2 analogues increase absorptive surface and slow transit throughout the remaining bowel, but a patient with an intact colon in continuity also gains from colonic salvage of fluid, electrolytes and short-chain fatty acids — so the same drug produces a larger measurable reduction in intravenous support. Patients with an end jejunostomy or ileostomy and no colon lose that amplifier, and have consistently been the harder group to help. STARS was stratified by anatomy for exactly this reason, and the stoma subgroup result — a 25.6% reduction against 7.8% on placebo — was the cleanest signal in the trial, partly because the placebo response in that group was so much smaller. The mirror image appeared at week 48 in the colon-in-continuity group, where 44.4% of placebo patients achieved at least one day off support and the drug could not separate from that.

Does apraglutide actually make the intestine grow?

In an uncontrolled setting, measurably so. A 52-week open-label metabolic balance study in nine patients with short bowel syndrome and colon in continuity reported that small bowel length increased from 29.7 to 40.7 cm on imaging, duodenal wall thickness increased by 0.8 mm, motility in the proximal colon slowed, faecal output fell by 253 g a day at four weeks, and wet weight and energy absorption both rose at 48 weeks. Parenteral support volume fell by 52%. Those structural findings are consistent with the preclinical work, which showed segment-specific intestinal growth in mice and enhanced adaptation in a neonatal piglet model of short bowel syndrome. The caution is that nine open-label patients produced twice the parenteral reduction seen in the placebo-controlled trial, which says a great deal about how suggestible this endpoint is and very little about whether the drug is twice as good as it looked.

Can I get apraglutide?

Only in a clinical trial. It is not approved by the FDA, the EMA or any other regulator, there is no brand name, and it is not available through compounding pharmacies or research-chemical suppliers. Short bowel syndrome with intestinal failure is managed in specialist intestinal rehabilitation centres, and those centres are the route to any trial that is recruiting — STARS-2 began opening sites in 2026, and an open-label extension called STARS Extend follows patients from the earlier studies. For patients needing GLP-2 therapy now, teduglutide is the approved option, and glepaglutide received a positive European regulatory opinion in September 2026.

Who Apraglutide Is NOT For

Contraindications
  • •Active gastrointestinal malignancy, or malignancy elsewhere in the gastrointestinal tract, given that GLP-2 analogues are intestinal growth factors; this is a class consideration carried over from approved agents rather than an apraglutide-specific finding.
  • •Known or suspected intestinal obstruction, where increasing mucosal bulk and fluid handling could worsen the blockage.
  • •Active biliary or pancreatic disease, which is monitored across the GLP-2 class because the hormone influences biliary flow and pancreatic secretion.
  • •Pregnancy and breastfeeding — no data exist.
  • •Children — the clinical programme has been conducted in adults, and paediatric short bowel syndrome is managed differently.
  • •Any use outside a clinical trial, since the drug is unapproved, has no established commercial presentation, and the exposure delivered by its phase 3 trial is known to have fallen short of what was intended.

Drug & Supplement Interactions

No formal drug interaction programme has been published for apraglutide, and the interactions that matter in this population are mostly pharmacodynamic rather than metabolic. The important one is with parenteral support itself: the drug's whole purpose is to increase enteral absorption, so continuing unchanged intravenous fluid and nutrition while absorption improves produces volume overload, and reducing it too aggressively produces dehydration. That is why trials specify weaning algorithms keyed to repeated fluid balance measurements rather than clinical impression. A second class consideration concerns orally administered drugs: by increasing absorptive surface and slowing gastric emptying and transit, GLP-2 analogues can alter the absorption of co-administered oral medicines, which matters particularly for narrow-therapeutic-index drugs and for the benzodiazepines and opioids often used in this population. The approved agents in the class carry exactly this caution. Pharmacokinetically, apraglutide is a peptide cleared by proteolysis rather than by cytochrome P450 enzymes, with very high plasma protein binding; severe renal impairment produced lower rather than higher exposure and required no dose adjustment, and a hepatic impairment study has been published. Conventional enzyme-mediated interactions are therefore not expected, but with no approved label there is no authoritative statement to rely on.

Safety Profile

Safety Information

Common Side Effects

Abdominal pain and distension, the expected consequence of increased intestinal fluid handling and mucosal growthNausea and vomitingStoma complications in patients with an ostomy, including increased output volume and peristomal changes as the mucosa thickensPeripheral oedema and fluid overload, a recognised GLP-2 class effect as absorption improves while intravenous support is still being taperedInjection-site reactionsUpper respiratory and catheter-related infections, which are common in this population independent of treatment

Cautions

  • • GLP-2 analogues are growth factors for the intestinal epithelium, and the class carries a theoretical risk of promoting neoplasia. Colonoscopy before starting and periodic surveillance afterwards is standard practice for approved agents in the class and would be expected for apraglutide.
  • • Fluid overload is a real and sometimes rapid problem. As absorption improves, parenteral support must be reduced on a schedule, and failing to taper can tip a patient into volume excess.
  • • Patients with a stoma need their output monitored closely during the first weeks, both because it can rise transiently and because the mucosal thickening can change how the appliance fits.
  • • Biliary and pancreatic disease are monitored in the GLP-2 class because the hormone affects biliary flow and pancreatic secretion.
  • • Apraglutide has not been studied in pregnancy, lactation or children.
  • • Exposure in severe renal impairment was lower rather than higher, and no dose reduction was required in that study, which is reassuring but based on 16 subjects.
  • • All of the above is drawn from a development programme of a few hundred patients. For a lifelong therapy in a rare disease, that is a thin base, and the STARS exposure shortfall means the safety dataset may not reflect the dose eventually marketed.

What We Don't Know

The central unknown is the one the regulator identified: the clinical trial that established efficacy did not deliver the intended exposure, so neither the efficacy nor the safety profile is anchored to the dose a licensed product would use. STARS-2 is designed to settle the efficacy question and will necessarily resettle the safety question with it. Beyond that, the usual rare-disease gaps apply. Nobody knows whether reductions in parenteral support translate into fewer catheter infections, less intestinal failure-associated liver disease, or better survival, because no trial in this field has been powered for those outcomes. Durability after stopping is only partly characterised — one study examined whether linear small-intestinal growth persists after long-acting GLP-2 analogues are discontinued, and the honest answer is that it does not fully. Long-term neoplasia risk under decades of intestinal growth factor exposure is unmeasured for the entire class. And the graft-versus-host disease programme rests on mouse transplantation models and mechanistic reviews rather than controlled human data.

Myths & Misconceptions

Myth

Apraglutide is approved for short bowel syndrome.

Reality

It is not approved anywhere. A rolling new drug application was started in January 2025 and halted in practice three months later when the FDA required a confirmatory phase 3 trial, which began opening sites in 2026. Teduglutide is the approved GLP-2 analogue in the United States; glepaglutide received a positive European regulatory opinion in September 2026. Apraglutide is available only in clinical trials.

Myth

Its phase 3 trial failed.

Reality

It met its primary endpoint — a 25.5% reduction in weekly parenteral support volume against 12.5% on placebo — and met the stoma-subgroup and days-off-support secondary endpoints as well. What went wrong was separate: a pharmacokinetic analysis during application preparation showed the trial had delivered lower drug exposure than planned, because of how the dose was prepared and administered. A positive trial at the wrong dose is a regulatory problem, not a negative result.

Myth

Once-weekly dosing is proven better than teduglutide's daily injection.

Reality

It is proven to be achievable, not better. The pharmacokinetic case is strong — thirty-fold lower clearance than teduglutide in rats, citrulline elevation persisting 10 to 17 days after a dose — and the convenience argument is obvious for a lifelong injection. But no trial has compared apraglutide with teduglutide in patients, on efficacy or on adherence, and the only ranking available comes from indirect network meta-analysis.

Myth

The 52% reduction in intravenous feeding shows how well it works.

Reality

That figure comes from a nine-patient open-label study with no control arm. The randomised, placebo-controlled trial in 163 patients produced 25.5% against 12.5% on placebo. The gap between the two is a measure of how much a structured parenteral weaning protocol achieves on its own, which is precisely why the uncontrolled number should not be quoted as the drug's effect.

Myth

GLP-2 analogues regrow the bowel permanently.

Reality

They maintain an adapted state while they are being given. Imaging in the open-label study did show small bowel length increasing from 29.7 to 40.7 cm over a year, and the mucosa genuinely thickens — but preclinical work on discontinuation found that linear small-intestinal growth is not fully durable once the drug stops, and parenteral support requirements return. This is maintenance therapy for a permanent anatomical loss, not a cure.

Published Research

26 studies

STARS Phase 3 Trial: Once-Weekly Apraglutide Reduces Parenteral Support in Short Bowel Syndrome-Intestinal Failure

The pivotal trial. 163 patients — 80 with a stoma, 83 with colon in continuity — randomised 2:1 to once-weekly apraglutide or placebo and stratified by anatomy. The primary endpoint was met: weekly parenteral support volume fell 25.5% versus 12.5% at week 24, and the stoma subgroup fell 25.6% versus 7.8%. More patients achieved at least one day a week off support, 43.0% versus 27.5%. But at week 48 in the colon-in-continuity group, days off support and enteral autonomy were 51.8% versus 44.4% and 12.5% versus 7.4%, neither close to significant. The placebo arm's performance in that group is the most informative number in the paper.

Phase 3 trialPMID: 42692160

Beyond intestinal failure: Expanding therapeutic frontiers of glucagon-like peptide-2 in gastrointestinal disease

ReviewPMID: 42273249

Early ecological changes in intestinal microbiota with the long-acting GLP-2 analog apraglutide in short bowel syndrome

Phase 2 analysisPMID: 41903849

Glucagon-like peptide agonists and use in short bowel syndrome - what about the side effects?

ReviewPMID: 41866997

Pharmacokinetics and Safety of Single-Dose Apraglutide in Individuals with Normal and Impaired Hepatic Function: A Phase 1, Open-Label Trial

Phase 1 trialPMID: 41545784

Positive clinical outcomes associated with use of glucagon-like peptide-2 (GLP-2) analogues in patients with intestinal failure: A systematic review and meta-analysis

Systematic reviewPMID: 41344401

Emerging novel therapies for steroid-refractory acute graft-versus-host disease: recent advances and future directions

ReviewPMID: 40865409

Use of glucagon-like polypeptide 2 analogs for intestinal failure

ReviewPMID: 39588923

The Long-Acting Glucagon-Like Peptide-2 Analog Apraglutide Enhances Intestinal Protection and Survival After Chemotherapy and Allogeneic Transplantation in Mice

Preclinical studyPMID: 39497378

Efficacy and safety of apraglutide in short bowel syndrome with intestinal failure and colon-in-continuity: A multicenter, open-label, metabolic balance study

Nine patients, 52 weeks, open-label, and the richest mechanistic dataset apraglutide has. Parenteral support volume fell 4,702 mL/week — 52% — and seven of nine patients achieved at least one day off support. Faecal output fell 253 g/day by week 4; wet weight and energy absorption rose by week 48; small bowel length on imaging increased from 29.7 to 40.7 cm, duodenal wall thickness by 0.8 mm, and proximal colonic motility slowed. Set beside the 25.5% reduction in the placebo-controlled trial, it is a textbook illustration of how much an uncontrolled weaning protocol can appear to achieve.

Phase 2 trialPMID: 39461299

Intestinal adaptation and rehabilitation in adults with short bowel syndrome

ReviewPMID: 38963563

Emerging drugs for the treatment of short bowel syndrome

ReviewPMID: 38761162

Efficacy and safety of glucagon-like peptide 2 in patients with short bowel syndrome: a systematic review and network meta-analysis

The only published attempt to rank the GLP-2 analogues against each other in patients, since no head-to-head trial exists. Indirect comparison across teduglutide, apraglutide and glepaglutide trials is the best available evidence for choosing between them, and its limitations — different endpoints, different weaning algorithms, different anatomical mixes — are exactly why a head-to-head trial would be worth running.

Network meta-analysisPMID: 38663565

Pharmacokinetics and Tolerability of a Single Dose of Apraglutide, a Novel, Long-Acting, Synthetic glucagon-like peptide-2 Analog With a Unique Pharmacologic Profile, in Individuals With Impaired Renal Function

Phase 1 trialPMID: 38465515

Characterization of the Pharmacokinetic and Pharmacodynamic Profile of Apraglutide, a Glucagon-Like Peptide-2 Analog, in Healthy Volunteers

Established the human dose. Six weekly subcutaneous doses of 1, 5 or 10 mg in healthy volunteers, with plasma citrulline — an amino acid made almost exclusively by enterocytes — as the pharmacodynamic readout. Clearance was 16.5 to 20.7 L/day, 5 mg produced the maximal citrulline response, and the elevation persisted 10 to 17 days after the final dose, which is the quantitative case for weekly rather than daily injection.

Randomized controlled trialPMID: 37316329

Pathophysiology of gastrointestinal acute graft-versus-host disease and the potential role of glucagon-like peptide 2

ReviewPMID: 36965050

Glucagon-like peptide-2 analogues for Crohn's disease patients with short bowel syndrome and intestinal failure

ReviewPMID: 36504557

An updated overview of glucagon-like peptide-2 analog trophic therapy for short bowel syndrome in adults

ReviewPMID: 35343263

How to manage a high-output stoma

ReviewPMID: 35300464

Apraglutide, a novel once-weekly glucagon-like peptide-2 analog, improves intestinal fluid and energy absorption in patients with short bowel syndrome: An open-label phase 1 and 2 trial

Phase 2 trialPMID: 35233802

Apraglutide, a novel glucagon-like peptide-2 analog, improves fluid absorption in patients with short bowel syndrome intestinal failure: Findings from a placebo-controlled, randomized phase 2 trial

The first controlled demonstration in patients that once-weekly apraglutide improves intestinal fluid absorption in short bowel syndrome with intestinal failure, and the study that justified taking the weekly schedule into phase 3.

Phase 2 trialPMID: 34287970

Comments on 'Pharmacological Characterization of Apraglutide a Novel Long-Acting Peptidic Glucagon-Like Peptide-2 Agonist for the Treatment of Short Bowel Syndrome'

The reply, written by four scientists from Zealand Pharma — the company that develops glepaglutide, the molecule the original paper characterised as less potent and less selective. Both documents sit in the same journal and a correction was issued alongside them. Worth reading as a reminder that comparative potency data between competing analogues are usually generated by one of the competitors.

CorrespondencePMID: 34039655

Durability of Linear Small-Intestinal Growth Following Treatment Discontinuation of Long-Acting Glucagon-Like Peptide 2 (GLP-2) Analogues

Addresses the question every patient on a lifelong injection asks: does the bowel keep what it gained if the drug stops? The answer for long-acting GLP-2 analogues is that linear small-intestinal growth is not fully durable after discontinuation — consistent with a growth factor that has to be present to keep the mucosa in its adapted state, and with the clinical observation that parenteral support needs return.

Preclinical studyPMID: 33241564

Site-Specific and Temporal Effects of Apraglutide, a Novel Long-Acting Glucagon-Like Peptide-2 Receptor Agonist, on Intestinal Growth in Mice

Preclinical studyPMID: 32144124

Pharmacological Characterization of Apraglutide, a Novel Long-Acting Peptidic Glucagon-Like Peptide-2 Agonist, for the Treatment of Short Bowel Syndrome

The paper that defines what apraglutide is for. Rat intravenous clearances of 25, 9.9, 2.8 and 0.27 mL/kg/min for native GLP-2, teduglutide, glepaglutide and apraglutide, with half-lives of 6.4, 19, 16 and 159 minutes, confirmed in monkey and minipig and translating to greater intestinal growth at longer dosing intervals. It also asserts that glepaglutide is less potent and less selective at the GLP-2 receptor than apraglutide or teduglutide — a competitor comparison published by the sponsor's own scientists, and formally disputed.

Preclinical studyPMID: 32075870

Novel Long-Acting GLP-2 Analogue, FE 203799 (Apraglutide), Enhances Adaptation and Linear Intestinal Growth in a Neonatal Piglet Model of Short Bowel Syndrome

Preclinical studyPMID: 30614011

Quick Facts

Class
GLP-2 Analogue
Tier
C
Evidence
Moderate
Safety
Moderate Data
Updated
Oct 2026
Citations
26PubMed

Also known as

FE 203799Apraglutide acetateLong-Acting GLP-2 Analog

Tags

InvestigationalGut HealthGLP-2InjectableRare Disease

Related Goals

Gut & Inflammation

Evidence Score

Overall Confidence58%

Clinical Trials

View Clinical Trials

Links to ClinicalTrials.gov for reference. Listing does not imply endorsement.