Icatibant
Bradykinin B2 antagonist
Also Firazyr, Sajazir, HOE 140, HOE-140, Icatibant acetate, JE049
- Evidence
- AStrong human evidence
- FDA status
- FDA approvedas of 2026-10-26
- Route
- Injection
- Studies cited
- 1 human0 animal or cell
A self-injected drug that stops swelling attacks in people with hereditary angioedema. In 88 adults it cut the time to relief from about 20 hours to 2 hours.
Sold for
Icatibant is the on-demand injection that people with hereditary angioedema carry to stop a swelling attack.
Studies say
Placebo-controlled trials show icatibant shortens attacks from about 20 hours to about 2 hours, which supports the approval and the A grade.
Why grade A. Approval rested on three randomised phase 3 trials (FAST-1, FAST-2 and FAST-3). The cited FAST-3 trial randomised 88 patients with moderate to very severe attacks to icatibant or placebo and found median time to symptom relief of 2 hours against 20 hours. 12
FDA. Icatibant is FDA-approved as Firazyr, approved August 25, 2011, for treating acute attacks of hereditary angioedema in adults, given by subcutaneous self-injection. Generic icatibant injections have been approved since 2020. 21
Written from 2 cited sources. Fact-checked 2026-10-27: 16 claims checked, 1 corrected. Last refreshed 2026-10-27. Not physician reviewed.
What this means for you
- What people take it for
- Stopping swelling attacks from hereditary angioedema.
- Can a US doctor prescribe it?
- Yes, FDA approved for sudden swelling attacks in adults with hereditary angioedema.
- Properly tested in people?
- Yes, in large controlled trials: an 88-adult trial.
Evidence checklist
- Randomised controlled trial FAST-3 placebo-controlledyes
- Human study over 100 people FAST-3 had 88 patientsno
- More than one research group Three phase 3 trials, FAST-1 to FAST-3yes
- Clinical outcomes, not surrogate markers Time to symptom relief in attacksyes
- Human safety data beyond case reports Trial and label safety datayes
Drawn from the cited studies below. A dash means the sources give no information.
What it is
Icatibant is a synthetic ten-amino-acid peptide that blocks the bradykinin B2 receptor. Hereditary angioedema is a genetic deficiency of C1 esterase inhibitor, and without that brake the body overproduces bradykinin, a peptide that makes blood vessels leak. The result is sudden swelling of the skin, gut or airway that can last days and, in the throat, can be fatal. 12
It was developed by Jerini and then Shire (now Takeda) and reached the US market in 2011 after an initial FDA rejection prompted the FAST-3 trial. It comes as a prefilled syringe for injection into the abdomen, and patients are trained to give it to themselves when an attack starts. 12
How it works
Bradykinin drives the swelling in hereditary angioedema by acting on B2 receptors on the inner lining of blood vessels, which loosen their junctions and let fluid flow into tissue. Icatibant competes with bradykinin for that receptor, so even though bradykinin remains high the vessels stop responding. It does not replace the missing C1 inhibitor and does not prevent future attacks; it treats the one that is happening. 1
What human research shows
FAST-3 randomised 88 adults with moderate to very severe skin or abdominal attacks to a single subcutaneous injection of icatibant (43) or placebo (45). Median time to a 50% reduction in symptom score was 2.0 hours with icatibant against 19.8 hours with placebo, and the groups separated within the first hour. Of the ten patients with laryngeal attacks, five with mild to moderate attacks were randomised (median 2.5 hours to 50% relief on icatibant, 3.2 on placebo) and five with severe attacks received icatibant open-label. The authors concluded icatibant was effective and generally well tolerated, and the result cleared the way for approval. 1
| Study | Model | Finding |
|---|---|---|
| FAST-3, Lumry 2011 | Humans, n=88, randomised double-blind placebo-controlled | Median time to 50% symptom relief was 2.0 hours with icatibant versus 19.8 hours with placebo. 1 |
| Firazyr label | FDA-approved prescribing information | Approved for acute attacks of hereditary angioedema in adults as a subcutaneous injection, with injection-site reactions the most common adverse event. 2 |
Safety
Almost every patient gets an injection-site reaction: redness, swelling, warmth, itching or pain at the site, usually resolving within hours. Other reported effects include fever, raised liver enzymes, dizziness and rash. Because bradykinin also has a protective role in the heart, the label notes caution in patients with acute ischaemic heart disease or stroke, though trials did not show a cardiac signal. Patients are told to seek emergency care after treating a laryngeal attack regardless of response. 12
Questions for your clinician
- How should I plan for laryngeal attacks after self-injecting?
- Do my heart conditions change whether icatibant is suitable?
- How does it compare with other hereditary angioedema treatments?
Questions people ask
Is icatibant FDA-approved?
Yes, as Firazyr since August 2011, for acute attacks of hereditary angioedema in adults aged 18 and older. Several generic versions have been approved since 2020. 21
How fast does icatibant work?
In the FAST-3 trial symptoms began to ease at a median of 2 hours after injection compared with about 20 hours on placebo, and the difference was measurable within the first hour. 1
Does icatibant prevent attacks?
No. It blocks the bradykinin receptor during an attack but does nothing to the underlying C1 inhibitor deficiency. Prevention uses different drugs such as C1 inhibitor concentrate or lanadelumab. 1
Can patients inject it themselves?
Yes. It is supplied as a prefilled syringe for injection under the skin of the abdomen, and self-administration after training is how it is intended to be used. 2
Citations
- Lumry 2011, Annals of Allergy, Asthma and Immunology: randomised placebo-controlled trial of icatibant for acute attacks of hereditary angioedema (FAST-3) doi.org
- NDC List: Firazyr (icatibant injection) label ndclist.com