Efficacy and Safety of Donidalorsen for Hereditary Angioedema.

BACKGROUND: Hereditary angioedema is a rare disorder characterized by episodic, potentially life-threatening swelling caused by kallikrein-kinin dysregulation. Long-term prophylaxis can stabilize this system. Donidalorsen, an antisense oligonucleotide, specifically reduces prekallikrein expression. METHODS: In this phase 3, double-blind, randomized trial, we assigned patients with hereditary angioedema to receive donidalorsen (80 mg subcutaneously) or placebo once every 4 or 8 weeks. The primary end point was the time-normalized number of investigator-confirmed hereditary angioedema attacks per 4 weeks (attack rate) from week 1 to week 25. RESULTS: A total of 90 patients received donidalorsen every 4 weeks (45 patients), donidalorsen every 8 weeks (23 patients), or placebo (22 patients). The least-squares mean time-normalized attack rate was 0.44 (95% CI, 0.27 to 0.73) in the 4-week group, 1.02 (95% CI, 0.65 to 1.59) in the 8-week group, and 2.26 (95% CI, 1.66 to 3.09) in the placebo group. The mean attack rate from week 1 to week 25 was 81% lower (95% CI, 65 to 89) in the 4-week group than in the placebo group (P<0.001) and 55% lower (95% CI, 22 to 74) in the 8-week group than in the placebo group (P = 0.004); the median reduction in the attack rate from baseline was 90% in the 4-week group, 83% in the 8-week group, and 16% in the placebo group. The mean attack rate during weeks 5 to 25 was 87% lower (95% CI, 72 to 94) in the 4-week group than in the placebo group (P<0.001) and 60% lower (95% CI, 25 to 79) in the 8-week group than in the placebo group. Donidalorsen administered every 4 weeks resulted in an improvement in the least-squares mean total score for the change at week 25 on the Angioedema Quality-of-Life Questionnaire (scores range from 0 to 100, with a score of 100 indicating the worst possible quality of life) that was 18.6 points (95% CI, 9.5 to 27.7) better than that with placebo (P<0.001). The most common adverse events were erythema at the injection site, headache, and nasopharyngitis; 98% of adverse events were mild or moderate in severity. CONCLUSIONS: Donidalorsen treatment reduced the hereditary angioedema attack rate, a finding that supports potential prophylactic use for hereditary angioedema. (Funded by Ionis Pharmaceuticals; OASIS-HAE ClinicalTrials.gov number, NCT05139810.).

Oral Sebetralstat for On-Demand Treatment of Hereditary Angioedema Attacks.

BACKGROUND: Approved on-demand treatments for hereditary angioedema attacks need to be administered parenterally, a route of administration that is associated with delays in treatment or withholding of therapy. METHODS: In this phase 3, double-blind, three-way crossover trial, we randomly assigned participants at least 12 years of age with type 1 or type 2 hereditary angioedema to take up to two oral doses of sebetralstat (300 mg or 600 mg) or placebo for an angioedema attack. The primary end point, assessed in a time-to-event analysis, was the beginning of symptom relief, defined as a rating of "a little better" on the Patient Global Impression of Change scale (ratings range from "much worse" to "much better") at two or more consecutive time points within 12 hours after the first administration of the trial agent. Key secondary end points, assessed in a time-to-event analysis, were a reduction in attack severity (an improved rating on the Patient Global Impression of Severity [PGI-S] scale, with ratings ranging from "none" to "very severe") at two or more consecutive time points within 12 hours and complete attack resolution (a rating of "none" on the PGI-S scale) within 24 hours. RESULTS: A total of 136 participants were assigned to one of six trial sequences, with 110 treating 264 attacks. The time to the beginning of symptom relief with the 300-mg dose and the 600-mg dose was faster than with placebo (P<0.001 and P = 0.001 for the two comparisons, respectively), with median times of 1.61 hours (interquartile range, 0.78 to 7.04), 1.79 hours (1.02 to 3.79), and 6.72 hours (1.34 to >12), respectively. The time to reduction in the attack severity with the 300-mg dose and the 600-mg dose was faster than with placebo (P = 0.004 and P = 0.003), with median times of 9.27 hours (interquartile range, 1.53 to >12), 7.75 hours (2.19 to >12), and more than 12 hours (6.23 to >12). The time to complete resolution was faster with the 300-mg and 600-mg doses than with placebo (P = 0.002 and P<0.001). The percentage of attacks with complete resolution within 24 hours was 42.5% with the 300-mg dose, 49.5% with the 600-mg dose, and 27.4% with placebo. Sebetralstat and placebo had similar safety profiles; no serious adverse events related to the trial agents were reported. CONCLUSIONS: Oral sebetralstat provided faster times to the beginning of symptom relief, reduction in attack severity, and complete attack resolution than placebo. (Funded by KalVista Pharmaceuticals; KONFIDENT ClinicalTrials.gov number, NCT05259917; EudraCT number, 2021-001226-21.).

Inhibition of Prekallikrein for Hereditary Angioedema.

BACKGROUND: Hereditary angioedema is characterized by recurrent and unpredictable swellings that are disabling and potentially fatal. Selective inhibition of plasma prekallikrein production by antisense oligonucleotide treatment (donidalorsen) may reduce the frequency of attacks and the burden of disease. METHODS: In this phase 2 trial, we randomly assigned, in a 2:1 ratio, patients with hereditary angioedema with C1 inhibitor deficiency to receive four subcutaneous doses of either donidalorsen (80 mg) or placebo, with one dose administered every 4 weeks. The primary end point was the time-normalized number of investigator-confirmed angioedema attacks per month (attack rate) between week 1 (baseline) and week 17. Secondary end points included quality of life, as measured with the Angioedema Quality of Life Questionnaire (scores range from 0 to 100, with higher scores indicating worse quality of life), and safety. RESULTS: A total of 20 patients were enrolled, of whom 14 were randomly assigned to receive donidalorsen and 6 to receive placebo. The mean monthly rate of investigator-confirmed angioedema attacks was 0.23 (95% confidence interval [CI], 0.08 to 0.39) among patients receiving donidalorsen and 2.21 (95% CI, 0.58 to 3.85) among patients receiving placebo (mean difference, -90%; 95% CI, -96 to -76; P<0.001). The mean change from baseline to week 17 in the Angioedema Quality of Life Questionnaire score was -26.8 points in the donidalorsen group and -6.2 points in the placebo group (mean difference, -20.7 points; 95% CI, -32.7 to -8.7). The incidence of mild-to-moderate adverse events was 71% among patients receiving donidalorsen and 83% among those receiving placebo. CONCLUSIONS: Among patients with hereditary angioedema, donidalorsen treatment resulted in a significantly lower rate of angioedema attacks than placebo in this small, phase 2 trial. (Funded by Ionis Pharmaceuticals; ISIS 721744-CS2 ClinicalTrials.gov number, NCT04030598.).

An investigational oral plasma kallikrein inhibitor for on-demand treatment of hereditary angioedema: a two-part, randomised, double-blind, placebo-controlled, crossover phase 2 trial.

BACKGROUND: Guidelines recommend effective on-demand therapy for all individuals with hereditary angioedema. We aimed to assess the novel oral plasma kallikrein inhibitor, sebetralstat, which is in development, for on-demand treatment of hereditary angioedema attacks. METHODS: In this two-part phase 2 trial, individuals with type 1 or 2 hereditary angioedema aged 18 years or older were recruited from 25 sites, consisting of specialty outpatient centres, across nine countries in Europe and the USA. Individuals were eligible if they had experienced at least three hereditary angioedema attacks in the past 93 days, were not on prophylactic therapy, and had access to and the ability to self-administer conventional attack treatment. In part 1 of the trial, participants were given a single 600 mg open-label oral dose of sebetralstat to assess safety, pharmacokinetics, and pharmacodynamics of the dose. Part 2 was a randomised, double-blind, placebo-controlled, two-sequence, two-period (2 × 2) crossover trial; participants were randomly assigned (1:1) to either sequence 1, in which they were given a single dose of 600 mg of sebetralstat to treat the first eligible attack and a second dose of placebo to treat the second eligible attack, or sequence 2, in which they were given placebo to treat the first eligible attack and then 600 mg of sebetralstat to treat the second eligible attack. Participants and investigators were masked to treatment assignment. The primary endpoint was time to use of conventional attack treatment within 12 h of study drug administration, which was assessed in all participants who were randomly assigned to treatment and who received study drug for two attacks during part 2 of the study. Safety was assessed in all participants who received at least one dose of study drug, starting in part 1. This study is registered with ClinicalTrials.gov, NCT04208412, and is completed. FINDINGS: Between July 2, 2019, and Dec 8, 2020, 84 individuals were screened and 68 were enrolled in part 1 and received sebetralstat (mean age 38·3 years [SD 13·2], 37 [54%] were female, 31 [46%] were male, 68 [100%] were White). 42 (62%) of 68 participants completed pharmacokinetic assessments. Sebetralstat was rapidly absorbed, with a geometric mean plasma concentration of 501 ng/mL at 15 min. In a subset of participants (n=6), plasma samples obtained from 15 min to 4 h after study drug administration had near-complete protection from ex vivo stimulated generation of plasma kallikrein and cleavage of high-molecular-weight kininogen. In part 2, all 68 participants were randomly assigned to sequence 1 (n=34) or sequence 2 (n=34). 53 (78%) of 68 participants treated two attacks (25 [74%] in the sequence 1 group and 28 [82%] in the sequence 2 group). Time to use of conventional treatment within 12 h of study drug administration was significantly longer with sebetralstat versus placebo (at quartile 1: >12 h [95% CI 9·6 to >12] vs 8·0 h [3·8 to >12]; p=0·0010). There were no serious adverse events or adverse event-related discontinuations. INTERPRETATION: Oral administration of sebetralstat was well tolerated and led to rapid suppression of plasma kallikrein activity, resulting in increased time to use of conventional attack treatment and faster symptom relief versus placebo. Based on these results, a phase 3 trial to evaluate the efficacy and safety of two dose levels of sebetralstat in adolescent and adult participants with hereditary angioedema has been initiated (NCT05259917). FUNDING: KalVista Pharmaceuticals.

Efficacy and safety of garadacimab, a factor XIIa inhibitor for hereditary angioedema prevention (VANGUARD): a global, multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Hereditary angioedema is a rare and potentially life-threatening genetic disease that is associated with kallikrein-kinin system dysregulation. Garadacimab (CSL312), a novel, fully-human monoclonal antibody that inhibits activated factor XII (FXIIa), is being studied for the prevention of hereditary angioedema attacks. The aim of this study was to evaluate the efficacy and safety of once-monthly subcutaneous administrations of garadacimab as prophylaxis for hereditary angioedema. METHODS: VANGUARD was a pivotal, multicentre, randomised, double-blind, placebo-controlled, phase 3 trial that recruited patients (aged ≥12 years) with type I or type II hereditary angioedema across seven countries (Canada, Germany, Hungary, Israel, Japan, the Netherlands, and the USA). Eligible patients were randomly assigned (3:2) to receive garadacimab or placebo for 6 months (182 days) by an interactive response technology (IRT) system. Randomisation was stratified by age (≤17 years vs >17 years) and baseline attack rate (1 to <3 attacks per month vs ≥3 attacks per month) for the adult group. The randomisation list and code were kept by the IRT provider during the study, with no access by site staff and funding representatives. All patients and investigational site staff, and representatives from the funder (or their delegates) with direct interaction with the study sites or patients, were masked to treatment assignment in a double-blind fashion. Randomly assigned patients received a 400-mg loading dose of subcutaneous garadacimab as two 200-mg injections or volume-matched placebo on day 1 of the treatment period, followed by five additional self-administered (or caregiver-administered) monthly doses of 200-mg subcutaneous garadacimab or volume-matched placebo. The primary endpoint was the investigator-assessed time-normalised number of hereditary angioedema attacks (number of hereditary angioedema attacks per month) during the 6-month treatment period (day 1 to day 182). Safety was evaluated in patients who received at least one dose of garadacimab or placebo. The study is registered with the EU Clinical Trials Register, 2020-000570-25 and ClinicalTrials.gov, NCT04656418. FINDINGS: Between Jan 27, 2021, and June 7, 2022, we screened 80 patients, 76 of whom were eligible to enter the run-in period of the study. Of 65 eligible patients with type I or type II hereditary angioedema, 39 were randomly assigned to garadacimab and 26 to placebo. One patient was randomly assigned in error and did not enter the treatment period (no dose of study drug received), resulting in 39 patients assigned to garadacimab and 25 patients assigned to placebo being included. 38 (59%) of 64 participants were female and 26 (41%) were male. 55 (86%) of 64 participants were White, six (9%) were Asian (Japanese), one (2%) was Black or African American, one (2%) was Native Hawaiian or Other Pacific Islander, and one (2%) was listed as other. During the 6-month treatment period (day 1 to day 182), the mean number of investigator-confirmed hereditary angioedema attacks per month was significantly lower in the garadacimab group (0·27, 95% CI 0·05 to 0·49) than in the placebo group (2·01, 1·44 to 2·57; p<0·0001), corresponding to a percentage difference in means of -87% (95% CI -96 to -58; p<0·0001). The median number of hereditary angioedema attacks per month was 0 (IQR 0·00-0·31) for garadacimab and 1·35 (1·00-3·20) for placebo. The most common treatment-emergent adverse events were upper-respiratory tract infections, nasopharyngitis, and headaches. FXIIa inhibition was not associated with an increased risk of bleeding or thromboembolic events. INTERPRETATION: Monthly garadacimab administration significantly reduced hereditary angioedema attacks in patients aged 12 years and older compared with placebo and had a favourable safety profile. Our results support the use of garadacimab as a potential prophylactic therapy for the treatment of hereditary angioedema in adolescents and adults. FUNDING: CSL Behring.

A phase 2 open-label extension study of prekallikrein inhibition with donidalorsen for hereditary angioedema.

BACKGROUND: Hereditary angioedema (HAE) is a potentially fatal disease characterized by unpredictable, recurrent, often disabling swelling attacks. In a randomized phase 2 study, donidalorsen reduced HAE attack frequency and improved patient quality-of-life (ISIS721744-CS2, NCT04030598). We report the 2-year interim analysis of the phase 2 open-label extension (OLE) study (ISIS 721744-CS3, NCT04307381). METHODS: In the OLE, the on-treatment study period consisted of fixed (weeks 1-13, donidalorsen 80 mg subcutaneously every 4 weeks [Q4W]) and flexible (weeks 17-105, donidalorsen 80 mg Q4W, 80 mg every 8 weeks [Q8W], or 100 mg Q4W) dosing periods. The primary outcome was incidence and severity of treatment-emergent adverse events (TEAEs). The secondary outcomes included efficacy, pharmacodynamic, and quality-of-life assessments. RESULTS: Seventeen patients continued in the OLE study. No serious TEAEs or TEAEs leading to treatment discontinuation were reported. Mean monthly HAE attack rate was 96% lower than the study run-in baseline rate (mean, 0.06/month; 95% confidence interval [CI], 0.02-0.10; median, 0.04 on-treatment vs. mean, 2.70/month; 95% CI, 1.94-3.46; median, 2.29 at baseline). Mean monthly attack rate for Q8W dosing (n = 8) was 0.29 (range, 0.0-1.7; 95% CI, -0.21 to 0.79; median, 0.00). Mean plasma prekallikrein and D-dimer concentrations decreased, and Angioedema Quality of Life Questionnaire total score improved from baseline to week 105 with donidalorsen. CONCLUSION: The 2-year interim results of this phase 2 OLE study of donidalorsen in patients with HAE demonstrated no new safety signals; donidalorsen was well tolerated. There was durable efficacy with a 96% reduction in HAE attacks.

An expert panel's review on patients with hereditary angioedema switching from attenuated androgens to oral prophylactic therapy.

Background: Hereditary angioedema (HAE) is a rare condition marked by swelling episodes in various body parts, including the extremities, upper airway, face, intestinal tract, and genitals. Long-term prophylaxis (LTP), prescribed to control recurring HAE attacks, is integral to its management. Previously, attenuated androgens (AAs) were the only oral LTP options. However, in 2020, berotralstat, an oral plasma kallikrein inhibitor, was approved in the United States. A 2018 survey of adults with HAE type I or type II showed that almost all the patients who used prophylactic HAE medication preferred oral treatment (98%) and felt that it fit their lifestyle better than injectable treatment (96%). Still, guidelines lack consensus on transitioning patients from AAs to alternative oral prophylactic therapy. Objective: This paper aims to share expert insights and patient feedback on transitioning from AAs to berotralstat, an alternative oral prophylactic therapy, from the perspective of clinicians with extensive experience in treating patients with HAE. Methods: A panel of five HAE specialists convened for a virtual half-day roundtable discussion in April 2023. Results: Discussions about transitioning from AAs to berotralstat were prompted by routine consultations, patient inquiries based on independent research, ineffective current treatment, or worsening AA-related adverse effects. For patients who switched from AAs, the physicians reported that the decision was influenced by the alternative therapy's ability to prevent HAE attacks, its safety, and the once-daily administration schedule. All expert panel members identified fewer AA-related adverse effects; better quality of life; and less severe, shorter, and less frequent HAE attacks as clinical or patient goals they hoped to achieve through the treatment switch. Conclusion: The emergence of new, highly specific LTP drugs for HAE calls for the development of comprehensive recommendations and guidelines for transitioning from AAs to alternative oral prophylactic therapy. The expert panel highlighted key factors to consider during the development of such guidelines.

Prophylactic use of an anti-activated factor XII monoclonal antibody, garadacimab, for patients with C1-esterase inhibitor-deficient hereditary angioedema: a randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: Hereditary angioedema is associated with dysregulation of the kallikrein-kinin system. Factor XII (FXII) is a key initiator of the kallikrein-kinin system, which produces bradykinin, a central mediator of angioedema. Garadacimab (CSL Behring) is a first-in-class, fully human, immunoglobulin G4 monoclonal antibody targeting activated FXII, intended to prevent attacks in patients with C1-esterase inhibitor-deficient hereditary angioedema (HAE-C1-INH). We aimed to investigate garadacimab as a treatment every 4 weeks for patients with HAE-C1-INH. METHODS: In this double-blind, placebo-controlled, phase 2 study, patients with HAE-C1-INH were recruited from 12 research centres in Canada, Germany, Israel, and the USA. Eligible patients were aged 18-65 years and must have had at least four attacks of any severity over a consecutive 2-month period during the 3 months before screening or initiation of previous hereditary angioedema prophylaxis. After a run-in period of 4-8 weeks, patients were randomly assigned (1:1:1:1), using an interactive response technology via block randomisation (block sizes of 1-4), to either placebo or 75 mg, 200 mg, or 600 mg garadacimab. Patients were given an initial intravenous loading dose, and then, on day 6 and every 4 weeks for 12 weeks, they were given a subcutaneous dose of their allocated treatment. The primary endpoint was the number of monthly attacks in the intention-to-treat population (defined as all patients who underwent screening, provided consent, and were assigned to treatment) during the 12-week subcutaneous administration period assessed in the 200 mg and 600 mg garadacimab groups versus placebo. Safety was assessed in all patients who received at least one dose or partial dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03712228. FINDINGS: Between Oct 29, 2018, and Aug 28, 2019, 54 patients were screened, of whom 32 were randomly assigned to either placebo (n=8) or 75 mg (n=9), 200 mg (n=8), or 600 mg (n=7) garadacimab. The median age was 39·5 years (28·0-52·5) and 18 (56%) of 32 patients were female and 14 (34%) were male. The median number of monthly attacks during the 12-week subcutaneous treatment period was 4·6 (IQR 3·1-5·0) with placebo, 0·0 (0·0-0·4) with 75 mg garadacimab, 0·0 (0·0-0·0) with 200 mg garadacimab, and 0·3 (0·0-0·7) with 600 mg garadacimab. Compared with placebo, the rate of attacks was significantly reduced with garadacimab at 200 mg (reduced by 100% [95% CI 98-101]; p=0·0002) and 600 mg (reduced by 93% [54-110]; p=0·0003). No serious adverse events, deaths, or adverse events of special interest (anaphylaxis, thromboembolic events, and bleeding events) were observed. INTERPRETATION: Garadacimab 200 mg and 600 mg every 4 weeks significantly reduced the number of monthly attacks versus placebo and was well tolerated during the study. Garadacimab is an efficacious, subcutaneous prophylaxis in patients with HAE-C1-INH and warrants phase 3 evaluation. FUNDING: CSL Behring.

Long-term lanadelumab treatment improves health-related quality of life in patients with hereditary angioedema.

BACKGROUND: Hereditary angioedema (HAE) is associated with a substantial disease burden. Lanadelumab reduced the HAE attack rate during 132 weeks of follow-up in the HELP open-label extension (OLE) Study (NCT02741596). OBJECTIVE: To measure the impact of long-term lanadelumab treatment on patient-reported outcomes (PROs). METHODS: Rollover patients (completed the 26-week HELP study [NCT02586805]) and nonrollovers (newly enrolled) received lanadelumab 300 mg every 2 weeks. PROs (Angioedema Quality of Life Questionnaire [AE-QoL], Short Form Health Survey 12-item version 2, Hospital Anxiety and Depression Scale, Work Productivity and Activity Impairment-General Health Questionnaire, and EQ-5D-5L questionnaire) were assessed at baseline (day 0 of HELP OLE) and various time points until the end-of-study visit. The Angioedema Control Test, Treatment Satisfaction Questionnaire for Medication, and Global Impression of Treatment Response were administered starting at week 52. RESULTS: The mean (SD) change in AE-QoL total score from baseline to end-of-study for rollovers (n = 90) was -10.2 (17.9), exhibiting further improvement from HELP in health-related quality of life (HRQoL); 48.9% of rollovers achieved the previously defined 6-point minimal clinically important difference. Nonrollovers (n = 81) reported a change of -19.5 (21.3). Controlled disease (Angioedema Control Test total score ≥10) was reported by 90.2% of rollovers and 95.9% of nonrollovers at the end of the study. Excellent treatment response was reported by 78.7% of patients and 82.4% of investigators. Results from other PROs indicated a slight improvement in anxiety, a high level of satisfaction with treatment, and increased work productivityor activity. CONCLUSION: Clinically meaningful improvement in HRQoL was exhibited with long-term lanadelumab treatment, supporting the benefit of lanadelumab therapy associated with attack prevention. TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: NCT02586805 (HELP Study) and NCT02741596 (HELP open-label extension).

Long-term prevention of hereditary angioedema attacks with lanadelumab: The HELP OLE Study.

BACKGROUND: The aim was to evaluate long-term effectiveness and safety of lanadelumab in patients ≥12 y old with hereditary angioedema (HAE) 1/2 (NCT02741596). METHODS: Rollover patients completing the HELP Study and continuing into HELP OLE received one lanadelumab 300 mg dose until first attack (dose-and-wait period), then 300 mg q2wks (regular dosing stage). Nonrollovers (newly enrolled) received lanadelumab 300 mg q2wks from day 0. Baseline attack rate for rollovers: ≥1 attack/4 weeks (based on run-in period attack rate during HELP Study); for nonrollovers: historical attack rate ≥1 attack/12 weeks. The planned treatment period was 33 months. RESULTS: 212 patients participated (109 rollovers, 103 nonrollovers); 81.6% completed ≥30 months on study (mean [SD], 29.6 [8.2] months). Lanadelumab markedly reduced mean HAE attack rate (reduction vs baseline: 87.4% overall). Patients were attack free for a mean of 97.7% of days during treatment; 81.8% and 68.9% of patients were attack free for ≥6 and ≥12 months, respectively. Angioedema Quality-of-Life total and domain scores improved from day 0 to end of study. Treatment-emergent adverse events (TEAEs) (excluding HAE attacks) were reported by 97.2% of patients; most commonly injection site pain (47.2%) and viral upper respiratory tract infection (42.0%). Treatment-related TEAEs were reported by 54.7% of patients. Most injection site reactions resolved within 1 hour (70.2%) or 1 day (92.6%). Six (2.8%) patients discontinued due to TEAEs. No treatment-related serious TEAEs or deaths were reported. Eleven treatment-related TEAEs of special interest were reported by seven (3.3%) patients. CONCLUSION: Lanadelumab demonstrated sustained efficacy and acceptable tolerability with long-term use in HAE patients.