Important Safety Information
- Anaphylaxis has been reported after administration of KALBITOR.
Because of the risk of anaphylaxis, KALBITOR should only be administered by a healthcare
professional with appropriate medical support to manage anaphylaxis and HAE.
Healthcare professionals should be aware of the similarity of symptoms between hypersensitivity
reactions and HAE and patients should be monitored closely.
Do not administer KALBITOR to patients with known clinical hypersensitivity to KALBITOR.
Do not administer KALBITOR to a patient who has known clinical hypersensitivity to KALBITOR.
WARNINGS AND PRECAUTIONS
In 255 HAE patients treated with intravenous or subcutaneous KALBITOR in clinical trials, 10 patients
(4%) experienced anaphylaxis. For the subgroup of 187 patients treated with subcutaneous KALBITOR,
5 patients (3%) experienced anaphylaxis. These reactions occurred within the first hour after dosing.
Symptoms associated with these reactions have included chest discomfort, flushing, pharyngeal edema,
pruritus, rhinorrhea, sneezing, nasal congestion, throat irritation, urticaria, wheezing, and hypotension.
Patients should be observed for an appropriate period of time after administration of KALBITOR, taking
into account the time to onset of anaphylaxis seen in clinical trials. Given the similarity in hypersensitivity
symptoms and acute HAE symptoms, patients should be monitored closely in the event of a hypersensitivity reaction.
The most common adverse events (≥3% and greater than placebo) in HAE patients were headache, nausea,
diarrhea, pyrexia, injection site reactions, and nasopharyngitis.
There is a potential for immunogenicity with the use of KALBITOR. Overall, 20.2% of patients seroconverted
to anti-ecallantide antibodies. Anti-ecallantide IgE antibodies were detected at a rate of 4.7% for tested
patients, and anti-P. pastoris IgE antibodies were also detected at a rate of 20.2%. Patients who seroconvert
may be at a higher risk of a hypersensitivity reaction. The long-term effects of antibodies to KALBITOR are not known.
KALBITOR should only be administered by a healthcare professional with appropriate medical support to manage
anaphylaxis and hereditary angioedema. Safety and effectiveness of KALBITOR in patients below 12 years of age have not been established.
Please see the Full Prescribing Information, including Boxed
Warning and Medication Guide.
Healthcare professionals should report all suspected adverse events associated with the use of KALBITOR.
Please contact Dyax Corp. at 1-888-452-5248. Alternatively, this information may be reported to the FDA MedWatch
System by phone at 1-800-FDA-1088, or by mail using Form 3500 at