Peptide education
Ecallantide
Kalbitor
Ecallantide is a prescription protein medicine for sudden attacks of hereditary angioedema (HAE). The U.S. product Kalbitor is approved for patients aged 12 and older. A healthcare professional gives it under conditions that allow treatment of anaphylaxis as well as the HAE attack.
In the EDEMA3 trial, the median treatment outcome score 4 hours after the dose was 50 with ecallantide and 0 with placebo. A higher score represented more improvement on that patient-reported measure.
Overview
Quick answer
Kalbitor treats an attack; it is not labeled as preventive treatment. Its boxed warning is for anaphylaxis, a serious allergic reaction whose symptoms may resemble HAE swelling.
How does ecallantide affect an attack?
It inhibits plasma kallikrein, an enzyme involved in producing bradykinin. Reducing bradykinin production targets a pathway associated with the swelling and pain of HAE attacks.
What does the U.S. label say about dosing?
A 30 mg dose consists of three 10 mg subcutaneous injections. If an attack persists, the label permits an additional 30 mg dose within 24 hours. A healthcare professional administers Kalbitor.
Why must a healthcare professional give it?
Anaphylaxis has occurred after Kalbitor. The required setting must have appropriate medical support for that reaction and the HAE attack itself.
Is Kalbitor used to prevent future attacks?
The U.S. label describes treatment of acute HAE attacks, not a preventive schedule. The need for prevention is a separate clinical decision.
Evidence
Evidence snapshot
The U.S. indication covers attacks, not routine prevention.
Median treatment outcome scores were 50 with ecallantide and 0 with placebo.
Mean change in symptom severity at 4 hours was -0.8 with ecallantide and -0.4 with placebo.
The label reports this across clinical-study patients treated intravenously or subcutaneously; 5 of 187 in the subcutaneous subgroup had anaphylaxis.
Claims
Common claims vs evidence
| Claim | Human evidence | Mechanistic evidence | Verdict |
|---|---|---|---|
| Ecallantide can improve symptoms during an acute HAE attack. | Two placebo-controlled trials reported better patient-rated symptom outcomes at 4 hours with 30 mg subcutaneous ecallantide. | Kallikrein inhibition reduces the production of bradykinin, which is implicated in HAE swelling. | Supported for the acute-attack population described in the label and trials. |
| A better symptom score means the attack always resolves quickly. | EDEMA3 measured patient-reported improvement at 4 hours. Its estimated time to significant improvement did not differ significantly from placebo. | The measured score is not a guarantee of complete or immediate resolution. | |
| Kalbitor is suitable for unsupervised self-injection. | Anaphylaxis occurred in clinical studies, and its symptoms may overlap with those of an HAE attack. | The label requires administration by a healthcare professional with appropriate medical support. |
Bottom line
Main takeaway
Kalbitor is an acute HAE medicine given by a healthcare professional because serious allergic reactions can occur.
The label addresses individual attacks; EDEMA3 and EDEMA4 measured symptom response after treatment.
EDEMA3 and EDEMA4 used related patient-reported scales and different primary outcomes at 4 hours.
Identity
What it is
Ecallantide is a recombinant 60-amino-acid protein. Kalbitor is supplied in single-dose vials for subcutaneous administration.
In HAE associated with deficient or dysfunctional C1 inhibitor, kallikrein activity can increase bradykinin formation. Ecallantide acts on kallikrein rather than the bradykinin receptor itself.
Use context
Routes, doses, and cycle patterns
Kalbitor's label specifies professional administration for acute HAE attacks.
Human studies and product labels
Kalbitor U.S. label
- Purpose
- Acute HAE attack in a patient aged 12 or older
- Context
- Label-reported prescription use
- Route
- Three subcutaneous injections given by a healthcare professional
- Amount
- 30 mg total, given as three 10 mg injections
- Frequency
- One dose; an additional 30 mg may be given within 24 hours if the attack persists
Medical support for anaphylaxis and HAE must be available.
EDEMA3
- Purpose
- Patient-reported response to an acute attack
- Context
- Randomized placebo-controlled study
- Route
- Subcutaneous
- Amount
- 30 mg versus placebo
- Frequency
- One initial dose
- Duration
- Primary outcome measured at 4 hours
The median treatment outcome score favored ecallantide at 4 hours.
EDEMA4
- Purpose
- Change in attack symptom severity
- Context
- Randomized placebo-controlled study
- Route
- Subcutaneous
- Amount
- 30 mg versus placebo
- Frequency
- One initial dose
- Duration
- Primary outcome measured at 4 hours
Mean symptom severity decreased more with ecallantide than placebo.
Research
Research evidence
Two randomized studies found improvements in patient-reported HAE symptoms after treatment. They were short comparisons during an attack and do not describe preventive use.
| Study / evidence area | Population | Design | Product context | Main outcome | Limitations | Weight |
|---|---|---|---|---|---|---|
| EDEMA3 | 72 randomized patients with acute HAE attacks | Double-blind, placebo-controlled phase 3 trial | 30 mg subcutaneous ecallantide versus placebo | Median treatment outcome score at 4 hours was 50 versus 0. | Time to significant improvement was not statistically different. Patients were observed and could receive other medical treatment. | Strong |
| EDEMA4 | 96 randomized patients with moderate or severe HAE attacks | Double-blind, placebo-controlled phase 3 trial | 30 mg subcutaneous ecallantide versus placebo | Mean change in symptom severity at 4 hours was -0.8 versus -0.4. | The controlled endpoint describes a short period after one attack. | Strong |
Cautions
Safety and unknowns
- The boxed warning describes anaphylaxis. A healthcare professional must give Kalbitor with medical support available for both anaphylaxis and HAE.
- The label reports 10 cases of anaphylaxis among 255 patients exposed by either intravenous or subcutaneous routes, including 5 cases among 187 patients in the subcutaneous subgroup. These study rates do not predict an individual's risk.
- Kalbitor is contraindicated in patients with known clinical hypersensitivity to it. Headache, nausea, diarrhea, fever, injection-site reactions, and nasopharyngitis are among the adverse reactions listed in the label.
- Safety and effectiveness below age 12 have not been established. Evidence for efficacy at ages 12 to 15 was extrapolated from older patients with supporting pharmacokinetic data.
Product quality
Product identity and quality
Kalbitor is a sterile prescription product supplied in single-dose vials.
Administration setting
The product's boxed warning requires professional administration with support for anaphylaxis and HAE.
Mechanism
How it is proposed to work
Ecallantide blocks plasma kallikrein. That reduces formation of bradykinin, a signal associated with swelling during HAE attacks.
Kallikrein acts before bradykinin reaches its receptor. Blocking the enzyme and blocking the receptor are different drug mechanisms.
Details
Technical details
Sources
References
- 1.
DailyMed. Kalbitor prescribing information
- 2.
PubMed. EDEMA3 randomized trial in acute hereditary angioedema
doi:10.1056/NEJMoa0905079 PMID:20818887 NCT00262080
- 3.
PubMed. EDEMA4 randomized trial in acute hereditary angioedema
PMID:20568386