Kalbitor: 7 things you should know

Medically reviewed by Carmen Pope, BPharm. Last updated on Jan 2, 2024.

1. How it works

• Kalbitor is a brand (trade) name for ecallantide which may be used to treat acute attacks of hereditary angioedema (HAE). HAE is a rare genetic condition that occurs in people with mutations to the C1-esterase inhibitor located on chromosome 11q, causing substantially lower levels of certain proteins (C1-INH and C4) in their bodies. These low levels trigger excessive activation of the complement pathway and another protein called kallikrein.
• Kalbitor works by binding to plasma kallikrein and stopping it from participating in the kallikrein-kinin system, a complex cascade that facilitates the conversion of kininogen to bradykinin, a proinflammatory substance that causes inflammation, swelling, and pain.
• Kalbitor belongs to the class of medicines known as hereditary angioedema agents. It may also be called a human plasma kallikrein inhibitor or an immunomodulator.

2. Upsides

• May be used to treat acute attacks of hereditary angioedema (HAE) in adults and adolescents aged 12 years and older.
• The recommended dose is three 10mg subcutaneous injections (30mg total), administered consecutively at 3 different sites (eg, abdomen, thigh, or upper arm) at least 2 inches (5cm) apart or away from the site of the HAE attack. If additional doses are needed within 24 hours these may be administered at the same injection sites or different ones.
• Is a potent, highly-selective, and reversible inhibitor of kallikrein.
• Only agent approved for treatment of all localizations of HAE attacks.
• No risk of viral contamination.
• Rapid onset of action.
• Subcutaneous administration.
• Well tolerated.
• Significantly improves HAE symptoms at 4 hours.
• Patients can access the OnePath personalized product support service to help navigate health insurance obstacles including coordinating with your specialty pharmacy.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

• Headache, nausea, diarrhea, fever, injection site reactions (bruising, swelling, pain, redness), fever, and a stuffy nose are the most common side effects reported.
• Anaphylaxis and other allergic reactions have been reported. Advise people to report any signs of an allergic reaction such as hives, rash, fast heartbeat, difficulty breathing (wheezing), chest tightness, feeling light-headed or faint, swelling of the face, lips, tongue, or throat, and to seek emergency help if needed. Because of this increased risk of anaphylaxis can only be administered by a health professional.
• Do not administer Kalbitor to those who are allergic to it.
• Does not prevent HAE. Another medication, Takhzyro (lanadelumab-flyo) does this.No products will cure HAE.
• There is also the potential for immunogenicity and antibody formation. Overall, 20% of patients treated with Kalbitor seroconverted to anti-Kalbitor antibodies, but these did not appear to adversely affect the response, safety, or pharmacokinetic parameters.
• There is no data regarding the use of Kalbitor in pregnant women, but animal studies have not revealed any evidence of harm. There is no data about using Kalbitor in women who are breastfeeding. Consider Kalbitor use if the benefits outweigh the risks.
• The safety of Kalbitor in children under the age of 12 has not been established.
• Not approved for self-administration.
• No generic is available.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

• Kalbitor works by binding to a protein called kallikrein and inhibiting its activity including the production of bradykinin. It may be used to treat acute hereditary angioedema (HAE) attacks in adults and adolescents aged 12 years and older and is effective at reducing symptoms such as pain, swelling, and inflammation associated with HAE attacks.

5. Tips

• Must be administered by a health professional because of the risk of anaphylaxis. These allergic reactions can be life-threatening and usually happen within 1 hour of receiving Kalbitor. Tell your doctor or nurse immediately if you have any signs of an allergic reaction such as hives, rash, fast heartbeat, difficulty breathing (wheezing), chest tightness, feeling light-headed or faint, swelling of your face, lips, tongue, or throat (note that some of these symptoms may resemble HAE). You may need emergency help.
• If you need help navigating health insurance obstacles including coordinating with your specialty pharmacy, ask your doctor about the OnePath personalized product support service or call 1-866-888-0660 Monday through Friday.
• Kalbitor has not been studied in pregnant or breastfeeding women. Talk to your healthcare provider about the risk of taking this drug during pregnancy or while breastfeeding especially if you are considering trying to become pregnant.
• Although there are no documented interactions with Kalbitor, you should tell your doctor about any medications, including vitamins and herbal supplements that you take.
• Read the medication guide that is handed to you with this medication.

6. Response and effectiveness

• The effectiveness of Kalbitor was evaluated in 2 RCTs (EDEMA4 and EDEMA3: 168 patients with HAE). These consisted of 64 patients with abdominal attacks, 55 with peripheral attacks, and 24 with laryngeal attacks. The outcomes of attack severity and patient response to treatment were measured using the Mean Symptom Complex Severity (MSCS) score and the Treatment Outcome Score (TOS). Patients treated with Kalbitor had a significantly larger decrease from baseline in their MSCS score than placebo (-0.8 EDEMA4 and -1.1 EDEMA3 vs -0.4 and -0.6 with placebo respectively) and TOS score (53 Vs 8 with EDEMA4 and 63 Vs 36 with EDEMA3) after 4 hours. 33% to 36% more patients in the placebo group required medical intervention.

7. Interactions

There are currently no documented interactions with Kalbitor, according to the product information.

Kalbitor is not metabolized by cytochrome P450 enzymes; therefore, interactions with concomitant medications that are substrates, inducers, or inhibitors of cytochrome P450 enzymes are unlikely.

Kalbitor can increase activated partial thromboplastin time (aPTT) due to an interaction of Kalbitor with the aPTT assay. There have been no reports of abnormal adverse bleeding events associated with increases in aPTT.

You should refer to the prescribing information for Kalbitor for any updates or newly noted interactions.

References

• Kalbitor (ecallantide) [Package Insert] Updated 11/2022. Takeda Pharmaceuticals America, Inc. https://www.drugs.com/pro/kalbitor.html

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Kalbitor only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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