FDA Approves Takeda’s Takhzyro to Prevent Hereditary Angioedema Attacks in Children 2 Years of Age and Older

Rare Daily Staff

The U.S. Food and Drug Administration has approved Takeda’s supplemental Biologics License Application for the expanded use of Takhzyro to prevent attacks of hereditary angioedema in pediatric patients 2 to less than 12 years of age.

Prior to the approval, the only approved routine prophylaxis treatment options for children 6 to less than 12 years of age required dosing every three to four days, and children with HAE 2 to less than 6 years of age had no approved prophylaxis treatment.

Hereditary angioedema (HAE) is a rare genetic disorder that results in recurring attacks of edema – swelling – in various parts of the body, including the abdomen, face, feet, genitals, hands, and throat. The swelling can be debilitating and painful. Attacks that obstruct the airways can cause asphyxiation and are potentially life-threatening. HAE affects an estimated 1 in 50,000 people worldwide. It is often under-recognized, under-diagnosed and under-treated. In a survey from 2017 (N=445), the average HAE diagnosis took 8.4 years after symptom onset.

“Today’s approval for Takhzyro in pediatric patients as young as 2 years of age brings a welcome and important addition to treatment options available for children living with HAE,” said Anthony Castaldo, president and CEO of the U.S. Hereditary Angioedema Association.

Takhzyro is a fully human monoclonal antibody that specifically binds and decreases plasma kallikrein activity and is indicated for prophylaxis to prevent attacks of HAE in patients 2 years of age and older. Takhzyro was originally approved in the United States in 2018 for prophylaxis to prevent attacks of HAE in adult and pediatric patients 12 years and older. It is currently available in more than 60 countries around the world and is supported by a robust clinical development program, which includes one of the largest prevention studies in HAE with the longest active treatment duration.

The sBLA approval was supported by extrapolation of efficacy data from the HELP study, a phase 3 trial that included patients 12 to less than 18 years of age, and additional pharmacokinetic analyses showing similar drug exposures between adults and pediatric patients, as well as safety and pharmacodynamic data from the SPRING study, an open-label phase 3 trial in 21 HAE patients 2 to less than 12 years of age.

The primary objectives of the SPRING study were the safety and pharmacokinetics of Takhzyro. The most common treatment-related treatment emergent adverse events in the study were injection site pain (29 percent), injection site erythema (14 percent), injection site swelling (5 percent), administration site pain (5 percent) and injection site reaction (5 percent). The prevention of HAE attacks was measured as a secondary objective.

Takhzyro reduced the rate of HAE attacks in pediatric patients by a mean of 94.8 percnet compared to baseline, from 1.84 attacks per month to 0.08 attacks during the 52-week treatment period (N=21). The majority of patients (76.2 percent, n=16) were attack-free with an average of 99.5 percent attack-free days. These efficacy results are from an open-label, non-controlled trial, and the study was not designed for statistical hypothesis testing. Further confirmatory studies are required to draw any conclusions from these data.

“Today’s approval of the expanded indication of Takhzyro represents a significant step forward for the HAE community as it helps some of its youngest patients who are living with the disease to have a long-term prophylaxis treatment available to them,” said Julie Kim, president, U.S. Business Unit and U.S. country head at Takeda.

Julie Kim, president, U.S. Business Unit and U.S. country head at Takeda