Teduglutide is FDA-approved. For adults, the label asks for a colonoscopy first.

Why this note exists

Many Field Notes so far have been about compounds whose human record is thin. This one is the opposite case, and it is worth reading for that reason. Teduglutide has published double-blind, placebo-controlled trials, an FDA label built on them, a pediatric phase 3, and a regulator that has since asked pointed questions of both drugs trying to follow it. What that record establishes is specific, and so is its safety section.

In the index generated on September 8, 2026, one of 108 vendors carried teduglutide, with eleven listings in vial sizes from 5 mg to 100 mg plus three multi-vial packs.[19] The approved product is a 5 mg single-dose vial supplied with a prefilled syringe of sterile water.[1]

A note on what kind of evidence this is: every efficacy and safety figure below is human data, with its design and participant count attached. One paragraph reports rodent carcinogenicity findings from the label and says so. Statements about the drugs still in development come from their sponsors and are labeled as sponsor statements. pepmg does not convert a labeled per-kilogram dose into an amount for a research vial.

The approval

What FDA approved, and what its advisers worried about

Teduglutide is a 33-amino-acid analog of glucagon-like peptide-2, a gut hormone, manufactured in Escherichia coli by recombinant DNA technology; the label gives its molecular weight as 3752 daltons.[1] The approval dates to December 21, 2012.[2] Drugs@FDA also records a May 16, 2019 supplement in the category "Efficacy-New Patient Population," and the current label, revised in September 2025, covers children from 1 year of age as well as adults.[1][2]

Before approval, FDA put the application to its Gastrointestinal Drugs Advisory Committee. On October 16, 2012 the committee "unanimously agreed that Gattex offers a clinical benefit that outweighs potential risks in patients with short bowel syndrome," while some members, as Healio reported it, "indicated concern over the small study sample (n=173) and lack of long-term safety data."[8] The same report described the adverse events observed in the trials as "relatively few but included malignancies, intestinal polyps and obstructions and incidence of cholecystitis."[8]

Europe authorised the same molecule as Revestive on 30 August 2012, and its orphan designation was withdrawn in September 2024 "at the end of the 12-year period of market exclusivity."[11] On 8 January 2026 the EU authorised Teduglutide Viatris, a generic of Revestive, for short bowel syndrome.[12] That is this year's regulatory change: the molecule is now old enough to be copied.

The pivotal evidence

Two adult trials, one dose that missed, and a pediatric phase 3

The adult efficacy package is two 24-week, randomized, double-blind, placebo-controlled trials in people who had depended on parenteral nutrition or intravenous fluids for at least 12 months and needed parenteral nutrition at least three times a week.[1]

Enrollment and results as reported in the primary publications. The label calls the 2012 trial Study 1 and the 2011 trial Study 3, and records 33 randomized to the higher dose, of whom 32 formed the analysis population. The 2012 trial is registered as STEPS.[1][3][9][4][6]

In the 2012 trial, a responder was a patient whose weekly parenteral volume fell by more than 20% from baseline at both week 20 and week 24. 27 of 43 patients on teduglutide (63%) responded, against 13 of 43 on placebo (30%), P = .002.[3] At week 24 the mean reduction was 4.4 ± 3.8 L a week from a baseline of 12.9 L on teduglutide, against 2.3 ± 2.7 L from 13.2 L on placebo (P < .001).[3] The mean patient was 50 years old and had been on parenteral support for six years.[1]

The earlier trial is the more instructive one. Its analysis tested the higher dose first, and on the primary endpoint, a graded response score, 0.10 mg/kg/day did not beat placebo: 8 of 32 against 1 of 16, p = 0.16; the 0.05 mg/kg/day group did, 16 of 35, p = 0.007.[4] The authors noted that the two doses cut parenteral volume by the same amount, 353 and 354 mL a day, and suggested that the higher-dose group's larger baseline requirement "may have accounted for this discrepancy." Three teduglutide-treated patients were completely weaned off parenteral support.[4] The label now states that 0.1 mg/kg/day "is not a recommended dosage."[1]

The two-year extension of the 2012 trial, STEPS-2, was open-label and summarized with descriptive statistics. Of 88 patients enrolled, 65 completed it, and 13 achieved full enteral autonomy.[5] Its response rates, as high as 28 of 30 in one group, are counted among completers only; they describe patients who stayed on the drug, not everyone who started it, and they are supportive, uncontrolled evidence.[5]

The pediatric phase 3 randomized 50 children double-blind to two doses and followed 9 more on standard care without blinding. The primary endpoint, at least a 20% reduction in parenteral support at week 24, was reached by 13 of 24 (54.2%) on 0.025 mg/kg, 18 of 26 (69.2%) on 0.05 mg/kg and 1 of 9 (11.1%) on standard care; two and three children on the two doses reached enteral autonomy.[6] Treatment-emergent adverse events were reported by 98% of children on teduglutide and 100% on standard care.[6] Nine children in an unblinded comparison arm is a thin control, and the label says as much in its own way: pediatric use "is supported by evidence from adequate and well-controlled studies in adults."[1]

The trial reports are sponsor-connected. The 2011 trial's authors declared consulting for NPS Pharmaceuticals and Nycomed, and the author lists of the long-term extension and the pediatric trial include employees of NPS Pharmaceuticals and Shire respectively.[4][5][6]

Read the endpoint before you read the effect

The central clinical question in these trials is how much intravenous nutrition and fluid a patient still needs. In the 2012 trial, parenteral support was reduced whenever 48-hour urine volumes exceeded baseline by at least 10%; a responder is someone who ended up needing less of it.[3] For people who need parenteral nutrition at least three times a week, which was the entry criterion, that is a meaningful outcome.[1] The approval does not establish benefits for unrelated gut disorders or general wellness.

The drug does grow intestinal lining. The 2011 trial reported that villus height, plasma citrulline and lean body mass rose significantly on teduglutide compared with placebo, and the 2012 trial also found higher citrulline, which its authors describe as "a biomarker of mucosal mass."[3][4] That intestinotrophic effect is how the benefit works, and the label's neoplasia warning points back to the same pharmacology.[1]

The gap

What the record does not cover

The approval rests on trials in short bowel syndrome with intestinal failure. A ClinicalTrials.gov search on September 15, 2026 returned 50 registered studies of teduglutide, 39 interventional and 11 observational. Most list short bowel syndrome; a handful list Crohn's disease, graft-versus-host disease, HIV, environmental enteric dysfunction or severe acute malnutrition.[10] None of those has produced a second approved indication.[1][2]

The healthy-volunteer data are pharmacology. In one double-blind study, 36 healthy adults received 4 mg a day or placebo for ten days to test whether the drug slows gastric emptying; it did not, and no serious adverse events were reported.[7] The label records that the highest dose studied in development was 80 mg a day for eight days.[1] The registry search turned up no controlled trial of teduglutide as a general gut-health or recovery agent in people with an intact intestine.[10]

Safety

The warning, and the human cases behind it

In the two adult placebo-controlled trials, the adverse reactions reported in at least 5% of teduglutide patients, and more often than on placebo, were led by abdominal pain (30% vs 22%), nausea (23% vs 20%), upper respiratory tract infection (21% vs 12%) and abdominal distension (20% vs 2%), followed by injection site reactions, vomiting, fluid overload (12% vs 7%) and hypersensitivity (10% vs 7%).[1] The label's warnings cover acceleration of neoplastic growth, intestinal obstruction, biliary and pancreatic disease, fluid overload, and increased absorption of oral medicines taken alongside it.[1]

The neoplasia warning rests on a small number of human cases, which the label reports in full. Three adults in the short bowel syndrome studies were diagnosed with malignancies, all men, all on 0.05 mg/kg/day in the open-label extension of the 2012 trial. One, who had abdominal radiation for Hodgkin's disease two decades earlier and a prior liver lesion on CT, was diagnosed with metastatic adenocarcinoma of unconfirmed origin after 11 months; two with extensive smoking histories were diagnosed with lung cancers after 12 and 3 months.[1]

Fourteen adults were diagnosed with gastrointestinal polyps after starting study treatment. In the placebo-controlled studies that was 1 of 59 on placebo and 1 of 109 on teduglutide; the other 12 arose in the extension studies, including two colorectal villous adenomas, four colorectal tubular adenomas and one serrated adenoma, with onsets from 3 to 29 months.[1] The extension cases have no comparison group, so they cannot show whether teduglutide raised the rate. They are why the label tells prescribers to look.

For adults the label asks for colonoscopy and upper GI endoscopy within six months before starting, again at the end of the first year, and then no less frequently than every five years if no polyp is found; if a gastrointestinal malignancy is diagnosed, it says to discontinue.[1] For children it asks for fecal occult blood testing first, with scoping if there is new or unexplained blood in the stool.[1]

Animal data, labeled as such: in 2-year subcutaneous studies dosed at about 15 to 199 times the human exposure in rats and 32 to 244 times in mice, teduglutide increased adenomas of the bile duct and jejunum in male rats, and in mice caused papillary adenomas of the gall bladder, plus jejunal adenocarcinomas in males at the high dose.[1] Those are rodent findings at multiples of the human dose, not human data.

The class

The drugs trying to follow it have found FDA harder to satisfy

Two longer-acting GLP-2 analogs have since gone to FDA, one with a filed application and one before filing, and neither is approved. On December 19, 2024 Zealand Pharma announced that FDA had issued a complete response letter for glepaglutide, stating the application "did not meet the full requirements for substantial evidence to establish the efficacy and safety of the to-be-marketed dose," and recommending "an additional clinical trial."[13] In the company's own summary of its pivotal trial, twice-weekly dosing reduced parenteral support significantly against placebo, while once-weekly dosing "did not achieve statistical significance."[13] Zealand now says it expects the EU review of glepaglutide to complete in the second half of 2026.[14]

Apraglutide's setback was also about dose. On April 14, 2025 Ironwood Pharmaceuticals said that "the exposure and dose delivered in the STARS Phase 3 trial were lower than planned due to dose preparation and administration," and that after talking to FDA "a confirmatory Phase 3 trial is needed to seek approval."[15] That trial, STARS-2, is registered as recruiting, triple-blind, with an estimated 124 participants, a primary outcome of relative change in weekly parenteral support volume at week 24, and an estimated primary completion in October 2028; Ironwood reported in August 2026 that it is actively recruiting.[16][17]

A 2026 review of the class says "[s]afety profiles remain favourable, with gastrointestinal symptoms, fluid balance issues, gallbladder events and injection-site reactions reported most frequently," and that "[c]ontinued long-term studies and registry data are essential."[18] The common thread in both setbacks is dose: for glepaglutide, FDA's letter named the to-be-marketed dose; for apraglutide, the sponsor's own analysis found the trial had delivered less drug than planned.[13][15]

Three things this note is not saying

First, it is not saying the approval was thin. Two randomized, double-blind trials, a pediatric phase 3, long-term extension data and a unanimous advisory committee view on benefit and risk make a serious package for a rare condition.[1][8]

Second, it is not saying teduglutide causes cancer. The human record is three malignancies with serious prior risk factors and polyps found mostly in uncontrolled extensions, and the rodent tumors appeared at many times human exposure. FDA's answer was a monitoring schedule, not a verdict.[1]

Third, it is not saying anything about what is in a research vial. The approved article is a sterile 5 mg vial from a licensed manufacturer; pepmg's index records prices for what one vendor lists, and pepmg makes no claim about the contents of any vendor's vial.[1][19]

What it is saying is narrower: "FDA-approved" is true of teduglutide and means a once-daily injection that helped adults who had needed intravenous feeding for at least a year to need less of it, at the one dose that worked, with a colonoscopy schedule attached.[1][3][4]

Questions people are asking