Study Design:
The study has 2-parts, studying the efficacy of deucrictibant versus placebo for prophylactic and on-demand treatment of angioedema attacks will be assessed in adult participants with BK-AE-nC1INH. Each part of the study is designed a randomized, double-blind, placebo-controlled cross-over trial. Up to 10 patients to be enrolled.
Deucrictibant has been adopted as the international nonproprietary name (INN) for the active ingredient, previously referred to as PHA121 or PHA-022121. Deucrictibant is under development as an orally administered bradykinin B2 receptor antagonist with potential for both acute therapeutic and prophylactic use in patients with different types of BK-mediated angioedema, including HAE-1/2, HAE with normal C1INH, acquired angioedema due to C1INH deficiency, and non-hereditary BK-mediated angioedema with normal C1INH.
Throughout the study (Parts 1 and 2), a diary will be used to record all symptoms and details of angioedema attacks, including on-demand treatments, as well as Patient Reported Outcomes (PROs). Participants need to have access to FDA approved on-demand angioedema medication and be able to treat any angioedema attack that may occur using standard of care on-demand therapies. In addition to the collected data on angioedema attacks, the diary will be used as a dosing diary for the daily intake of study drug treatment in Part 1.
Part 1 will evaluate the efficacy and safety of deucrictibant administered orally for prophylaxis against angioedema attacks in patients with BK-AE-nC1INH. After providing written informed consent, participants will be screened for eligibility. Eligible participants will be enrolled in the study. Participants receiving angioedema medications for long-term prophylaxis (LTP) will discontinue and washout these medications prior to Screening.
Dosing schedule: QD administration of study drug or placebo (double blind) throughout the Treatment Period consisting of deucrictibant (40 mg strength) XR tablet and matching placebo for oral use.
The duration of an individual's participation in Part 1 is up to 24 weeks (12 weeks on each deucrictibant and placebo, in random order).
Participants will be randomized in a 1:1 ratio to receive deucrictibant 40 mg XR tablet or matching placebo once daily (QD) each for 12 weeks and then participants will be crossed over, for a total of 24 weeks of treatment.
Part 2: After completion of Part 1, a study visit will be conducted at Week 24, at which the enrolled participants will be re-randomized in Part 2 on a 1:1 ratio to a treatment sequence to receive deucrictibant 20 mg soft capsule following by matching placebo or vice versa, with one capsule given for each of 2 attacks. Participants will self-administer blinded study drug in the assigned treatment sequence at home to treat 2 non-laryngeal qualifying angioedema attacks (at least one attack symptom \[skin pain, skin swelling, or abdominal pain\] has reached the individual item score of ≥20 in VAS-3). The time of administration of study drug as well as rescue medication must be recorded in the patient diary.The expected duration of Part 2 is up to 16 weeks.
End-of-Treatment and End-of-Study visits will occur within 7±2 days and 28 days (-14 days), respectively, after treatment of the second attack in Part 2.
Dosing schedule: Administration of study drug for acute angioedema attacks, dosing consists of deucrictibant (20 mg strength) soft capsule and matching placebo for oral use.
The duration of treatment in Part 2 is approximately 16 weeks.
Efficacy will be assessed based upon the occurrences of angioedema attacks, which will be confirmed by Investigators. During Screening, site personnel will discuss with participants the requirements for reporting angioedema attacks, including the information that is to be captured for each angioedema attack.
A Statistical Analysis Plan (SAP) will be finalized prior to database lock and will include a more technical and detailed description of all planned statistical analyses of all study endpoints.
The analysis of safety and tolerability will be performed on the Safety Analysis Set (ie, all randomized participants who have received at least 1 dose of study drug). Treatment-emergent AEs (TEAEs) are defined as AEs that start or pre-existing AEs that have worsened after the initiation of study drug.
The number and percentage of participants with TEAEs will be summarized by treatment group by body system organ class (SOC) and preferred term using the Medical Dictionary for Regulatory Activities (MedDRA®). Clinical laboratory data, vital signs, physical examination, and ECG data will be presented in summary tables and individual listings by treatment group.
