Source: FDA label
| Molecular formula | C305H442N88O91S8 |
|---|---|
| Molecular weight | 7054 g/mol |
| Registered trials | 13 |
| PubChem CID | 44152182 |
| Drug class | Plasma Kallikrein Inhibitor [EPC] |
| Brand names | Kalbitor |
Boxed warning: The FDA label for this compound includes a boxed warning, the FDA's strongest safety warning. See the full prescribing information for details.
Mechanism of Action
12.1 Mechanism of Action Hereditary angioedema (HAE) is a rare genetic disorder caused by mutations to C1-esterase-inhibitor (C1-INH) located on Chromosome 11q and inherited as an autosomal dominant trait. HAE is characterized by low levels of C1-INH activity and low levels of C4. C1-INH functions to regulate the activation of the complement and intrinsic coagulation (contact system pathway) and is a major endogenous inhibitor of plasma kallikrein. The kallikrein-kinin system is a complex proteo
People experiencing a sudden hereditary angioedema attack want to know whether a treatment actually works and what risks come with it. Ecallantide, sold as Kalbitor, is a targeted injectable therapy built specifically for this rare genetic condition.
Key takeaways
- Ecallantide (Kalbitor) is a plasma kallikrein inhibitor approved for acute hereditary angioedema attacks.
- It is approved for patients 12 years of age and older.
- The label carries a boxed warning.
- Evidence includes 13 registered trials, including a completed Phase 3 study in HAE patients.
- FAERS reports for ecallantide are led by hereditary angioedema itself, reflecting its use in that population, followed by malaise and headache.
What Ecallantide Is
Ecallantide belongs to a drug class called plasma kallikrein inhibitors. Hereditary angioedema results from low activity of a protein called C1-esterase-inhibitor, which normally helps regulate the kallikrein-kinin system. By inhibiting plasma kallikrein directly, ecallantide interrupts this pathway during an acute attack.
What Ecallantide Is Approved For
Kalbitor is indicated for treatment of acute attacks of hereditary angioedema in patients 12 years of age and older. It is the only approved brand of ecallantide referenced in the label. The label includes a boxed warning, so prescribers and patients should be aware that added precautions accompany its use.
What The Evidence Shows
Ecallantide has been studied across 13 registered clinical trials. A completed Phase 3 trial evaluated the efficacy and safety of the compound, then known as DX-88, for treating acute HAE attacks. Separate Phase 2 studies explored its use in reducing surgical blood loss during cardiac procedures, one of which was terminated and one of which was completed.
Reported Side Effects
Reports submitted to FAERS for ecallantide are counts of adverse event reports, not confirmed incidence or proof of causation. The most frequently reported term is hereditary angioedema itself, likely reflecting the underlying condition being treated rather than a drug effect. Other commonly reported terms include off label use, drug ineffective, malaise, headache, dose omission issues, pain, and hypersensitivity reactions.
FAQ
What is ecallantide used for?
Ecallantide, sold under the brand name Kalbitor, is approved to treat acute attacks of hereditary angioedema in patients 12 years of age and older. It works by inhibiting plasma kallikrein, an enzyme overactive during these attacks due to low C1-esterase-inhibitor activity.
Does ecallantide have a boxed warning?
Yes, the FDA label for Kalbitor (ecallantide) includes a boxed warning. Patients and caregivers should review the full prescribing information for details on this warning.
What clinical trials support ecallantide's approval?
Ecallantide has been studied in 13 registered clinical trials. A completed Phase 3 trial assessed its efficacy and safety for treating acute hereditary angioedema attacks, supporting its approved use.
What are the most commonly reported side effects of ecallantide?
FAERS reports for ecallantide most frequently mention hereditary angioedema, likely reflecting the treated condition, along with malaise, headache, and hypersensitivity reactions. These are counts of submitted reports, not confirmed rates of incidence or causation.
Is ecallantide the same as Kalbitor?
Yes, Kalbitor is the approved brand name for ecallantide, a plasma kallikrein inhibitor used to treat acute hereditary angioedema attacks.
This page is an editorial information resource. It does not sell, prescribe, or recommend any medication.
Content is editorial information, not medical advice. Talk to your doctor before any treatment decision.
Sources: FDA label (DailyMed) ClinicalTrials.gov FDA Adverse Event Reporting System (FAERS) PubChem
Updated 2026-08-10