Trial Outcomes & Findings for A Study of Icatibant (TAK-667) in Japanese Children and Teenagers With Acute Attacks of Hereditary Angioedema (NCT NCT04654351)

Participants took part in the study at 2 investigative sites in Japan from 15 January 2021 to 27 July 2021.

Participants with a diagnosis of hereditary angioedema (HAE) type I or II were enrolled in a single arm to receive TAK-667 single-dose per attack. Up to two additional injections were permitted per attack. Participants who subsequently experienced an acute attack continued to receive TAK-667 for up to a total of three eligible icatibant-treated attacks.

Due to risk of identification, data for age is not reported to protect participant privacy.

An adverse event (AE) means any untoward medical occurrence in a participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. A treatment-emergent adverse event (TEAE) was defined as any adverse event occurring after the start of Icatibant administration of the treatment period.

Injection sites were examined for erythema, swelling, cutaneous pain, burning sensation, itching/pruritus, and warm sensation. Data for injection site reactions were collected separately from general reports of AEs. As pre-defined in the protocol, an injection site reaction not meeting SAE criteria was not required to be reported additionally as an AE.

An AE means any untoward medical occurrence in a participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. A TEAE was defined as any AE occurring after the start of Icatibant administration of the Treatment Period. A resting 12-lead ECG was recorded and reported for participants shifts from within normal limits at baseline to abnormal, but not clinically significant, or abnormal and clinically significant after study drug administration.

An AE means any untoward medical occurrence in a participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. A TEAE was defined as any AE occurring after the start of Icatibant administration of the Treatment Period. Vital signs included body temperature (oral), sitting blood pressure (after 5 minutes resting), respiration rate and pulse (beats per minute \[bpm\]).

An AE means any untoward medical occurrence in a participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. A TEAE was defined as any AE occurring after the start of Icatibant administration of the Treatment Period. The laboratory parameters included hematology, serum chemistries, and urinalysis.

An AE means any untoward medical occurrence in a participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. A TEAE was defined as any AE occurring after the start of Icatibant administration of the Treatment Period. Blood samples were collected to assess follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, and progesterone in females, and FSH, LH, and testosterone in males.

Serum samples for immunogenicity testing were collected for determination of anti-icatibant antibodies. If hypersensitivity was observed, it was reported as an AEs of special interest. An AE means any untoward medical occurrence in a participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product.

The time to onset of symptom relief, defined as the duration of time in hours from the time of icatibant administration to the earliest time at which at least a 20% improvement is observed in the average post-treatment score with no worsening of any single component score. Investigator-rated symptom score was used for assessment and scoring of cutaneous, abdominal, and laryngeal symptoms of acute HAE attacks related to daily activities. The score ranged from 0 to 4 and each number of scores meant the following: 0 = none; absence of symptoms, 1 = mild (no to mild interference with daily activities), 2 = moderate (moderate interference with daily activities), 3 = severe (severe interference with daily activities), 4 = very severe (very severe interference with daily activities).

The time to onset of symptom relief, defined as the duration of time in hours from the time of icatibant administration to the earliest time at which the post-treatment score improved by at least 1 level. Participants of 4 years age and older self-assessed their HAE-related pain using the FPS-R instrument. FPS-R is a self-reported measure used to assess the intensity of children's pain and it is scored using a 0 to 10 scale (0=no pain to 10=very much pain).

The time to onset of symptom relief, defined as the earliest time at which a 20% improvement is observed in the total post-treatment score. Participants of younger than 4 years age underwent investigator assessment of HAE-related pain (cutaneous, abdominal, and laryngeal) using the FLACC compartmental pain scale. Each of the 5 categories were scored from 0 to 2. Face(F): 0 (no particular expression/smile) - 2 (frequent to constant frown clenched jaw quivering chin); Legs(L): 0 (normal position/relaxed) - 2 (kicking/legs drawn up); Activity(A): 0 (lying quietly, normal position, moves easily) - 2 (arched rigid/jerking); Cry(C): 0 (No cry \[awake/asleep\]) - 2 (crying steadily/screams/sobs or frequent complaints); Consolability(C): 0 (content/relaxed) - 2 (difficult to console/comfort), resulting in a total score between 0 and 10.

Rescue medication included therapies for HAE used for HAE attack and symptomatic treatment used in order to improve symptoms of angioedema (eg, pain and nausea).

Investigator-rated symptom score was used for assessment and scoring of cutaneous, abdominal, and laryngeal symptoms of acute HAE attacks related to daily activities. The score ranged from 0 to 4 and each number of scores means following; 0 = none; absence of symptoms, 1 = mild (no to mild interference with daily activities), 2 = moderate (moderate interference with daily activities), 3 = severe (severe interference with daily activities), 4 = very severe (very severe interference with daily activities).

Time to initial symptom improvement reported by investigator, was defined as the duration of time in hours from icatibant administration until the time when overall participant improvement was first noted by investigator.

Time to initial symptom improvement reported by participant, defined as the duration of time in hours from icatibant administration until the time when overall participant improvement was first noted by participant, participant's parent or participant's legal guardian.