This article is part of an extensive feature on the 2024 HAEi Regional Conference Americas, published in Global Perspectives #1 2024

20 submitted abstracts were accepted for presentation during the Scientific Track of the 2024 HAEi Regional Conference Americas. Fifteen of these were presented as posters and five as oral abstracts.

Each poster presenter had the opportunity to share key information in a 2-minute short talk before being at their posters to answer questions from participants as they walked the room.

Below is a summary of all the posters, including interviews with some presenters.

1. Registry of Members of the Association of Patients with Hereditary Angioedema of Peru
Dr. Oscar Calderón presented this paper, which reported on the current status of a registry of HAE patients maintained by HAE Peru (the Peruvian HAE patient association.)

Key findings were that:

  • C4 complement testing is performed in most centers
  • Access to C1-inhibitor antigenic and functional testing is increasing
  • Patients have access to tranexamic acid and attenuated androgens for prophylaxis
  • No specific long-term prophylaxis is available
  • Icatibant is the only HAE-specific medicine available for the treatment of acute attacks

In conclusion, Dr. Calderón said that laboratory diagnosis had improved in recent years, and treatment is available, but their objective is to gain access to more specific treatments for HAE.

2. Early-onset Response to the Oral Bradykinin B2 Receptor Antagonist Deucrictibant Immediate-Release Capsule in Patients with Hereditary Angioedema Attacks
Prof. Marcus Maurer told attending physicians that this research was conducted to evaluate how quickly deucrictibant worked to begin resolving an acute HAE attack.

Prof. Maurer concluded that deucrictibant significantly reduces the time to onset of symptom relief. Compared to placebo, the time to onset of relief was 1.89-2.15 hours for deucrictibant and 7.62 hours for placebo.

Prof. Maurer indicated that, using another measure, the time to end of progression was 25-26 minutes for patients treated with deucrictibant, compared to 20 hours for those who received a placebo.

3. Registry of Members of the Association of Patients with Hereditary Angioedema in the Republic of Panama
Dr. Olga Barrera presented her data, which looked at confirmed HAE patients from Panama who registered with the Panamanian patient association up to December 2023.

Dr. Barrera indicated that 31 patients with diagnosed HAE were identified in the patient association database, yet the global prevalence data indicates there should be 84 patients with HAE. The research showed that out of 560 reported attacks in 2023, the majority were mild. The age of onset was variable, and prodromes were reported in 20% of patients.

Dr. Barrera concluded that more data is needed to understand the true picture of HAE in Panama.

4. Efficacy and Safety of the Oral Bradykinin B2 Receptor Antagonist Deucrictibant Immediate-release Capsule in Treatment of Hereditary Angioedema Attacks: RAPIDe-3 Phase 3 Trial Design
Prof. Grumach presented on upcoming research on the potential new HAE medicine deucrictibant. She said the key objectives of the study were to evaluate the efficacy of deucrictibant as an on-demand therapy compared with placebo in terms of symptom relief during an attack, as well as safety and tolerability.

Prof. Grumach presented key aspects of the trial’s design, including that approximately 120 patients will be enrolled globally and that the primary endpoint will be the time to onset of symptom relief. This will be measured using patient-reported outcome tools.

Prof. Grumach concluded that this is a planned phase 3 study, to investigate the efficacy and safety of deucrictibant for on-demand treatment of HAE attacks.

5. Anxiety Associated with Refilling On-demand Therapy for HAE Attacks Contributes to Treatment Delay and Non-treatment
Prof. Grumach also spoke to this research. She told the audience that the study aimed to characterize treatment patterns and anxiety associated with on-demand treatment, including refilling on-demand treatment.

Prof. Grumach described the key findings from 107 patients with HAE type I and type II. She indicated that half used only on-demand therapy. 86% of patients indicated that they do not immediately treat all HAE attacks, with the more common reason (37%) being because of anxiety about getting more on-demand therapy.

Prof. Grumach concluded that this anxiety about not being able to refill on-demand therapy quickly is experienced by people living with HAE, and has an impact on their treatment decisions, leading to delay and non-treatment of attacks.

6. HAE Attacks in Canadian Patients with HAE: Triggers and Treatment Based on Data from the 2020 National Survey
Michelle Cooper from HAE Canada spoke on this paper. She told the delegates that the objective was to use recent survey data to compare attacks, triggers, and treatment of HAE C1-inhibitor deficiency and HAE with normal C1 patients.

Michelle Cooper described the key findings:

  • Patients with HAE with normal C1 have more frequent attacks than those with HAE C1-inhibitor deficiency
  • All HAE patients treat attacks mainly with plasma-derived C1INH and icatibant
  • Stress is an important trigger for HAE attacks. Other triggers include menstruation and contraception in women.
  • More targeted treatments for patients with HAE with normal C1 may reduce attacks and improve quality of life

7. Characterizing the Negative Impact of Delayed On-demand Treatment of HAE Attacks
Dr. Ricardo Zwiener spoke on this paper. He outlined the research’s key objective: to describe the impact that delaying treatment of an HAE attack may have on people living with HAE.

Dr. Zwiener said that the results highlighted that delayed treatment of HAE attacks negatively impacts the time to feeling in control of an attack and the time to feeling fully recovered. The patients’ responses indicated that people living with HAE understand the importance of treating early in their HAE attack journey and recognize that earlier treatment translates to quicker recovery. It was also the case that patients also recognized that their anxiety decreases once they realize they are recovering from an attack.

8. Characterization of Prodromes in Hereditary Angioedema: Findings from an Online Patient Forum
Prof. Riedl presented data from this study, which used a structured online survey to better understand and describe prodromes in patients with HAE.

In total, 64 patients responded with their experience. 91% indicated that they had previously experienced prodromes, with 44% responding that their prodromes appear 0-4 hours before an HAE attack. The most common 5 prodromes were gastrointestinal issues, fatigue/tiredness, soreness or aches, itching, or mood changes.

Prof. Riedl concluded that most patients report they experience or have experienced prodromes, but that due to the unpredictable nature of HAE, patients who do have prodromes can still have attacks without any prodromal symptoms. He told delegates that it is important to have individualized conversations with patients about prodromes as these can differ greatly between individuals.

9. Characteristics of Hereditary Angioedema Attacks Among Long-term Prophylaxis Users
Although not an abstract author, Dr. Maeve O’Connor, who was familiar with this research, gave the short talk. She told the audience that the authors aimed to characterize HAE attacks among non-androgen long-term prophylaxis and on-demand-only users. The research was conducted in partnership with the US HAE Association (HAEA).

Dr. O’Connor outlined the key findings from the research and concluded:

  • The location and duration of recent attacks were similar between HAE patients on long-term prophylaxis and those using on-demand treatment only
  • The majority of patients delayed treatment of their last attack until they considered it moderate. A smaller proportion waited until the attack was severe or very severe.
  • Earlier treatment was associated with a shorter attack duration, regardless of long-term prophylaxis use
  • Although non-androgen long-term prophylaxis is effective at reducing HAE attack frequency, access to and education on the use of on-demand treatments remains important

10. Delayed On-demand Treatment of Hereditary Angioedema Attacks: Patient Perceptions and Associated Barriers
Dr. Maeve O’Connor presented her research, which was conducted with colleagues on sites across the USA. The research assessed patient perceptions of ‘early’ on-demand use versus actual time to treatment, in conjunction with barriers contributing to treatment delay.

Dr. O’Connor described the methods as working in partnership with the US HAE Association (HAEA). The HAEA recruited people with HAE type I and type II to participate in a short, self-reported online survey about their last treated attack.

Dr. O’Connor concluded that despite believing they were treating attacks early, many patients didn’t meet the guideline recommendations for prompt on-demand treatment after recognizing an HAE attack. She said the most common barrier to earlier treatment was uncertainty about whether the attack was real. Other barriers were a belief that the attack would be mild and wanting to save treatment for a severe attack. Dr. O’Connor said the findings highlight a need to do more to ensure guidelines are implemented and address barriers to delays in treating acute attacks.

11. Findings and Insights from a Colombian National Survey on Hereditary Angioedema due to C1-Inhibitor Deficiency
This research aimed to describe the clinical characteristics of HAE patients in Colombia and compare them to the need for treatment with long-term prophylaxis.

The research looked at 274 patients diagnosed with HAE by the 42 medical specialists who participated in it. The authors concluded that there is under-reporting and under-diagnosis of HAE. They also concluded that there is an impact of an HAE diagnosis in Colombia, with a significant percentage of patients having negative quality of life. About half of the patients studied required long-term prophylaxis, according to the authors.

12. Treatment Patterns of Patients Requiring Redosing of an On-demand Treatment After the Return of an HAE Attack
Dr. William Lumry was asked about this research by Global Perspectives. He told us:
My poster looked at the most recent attack reported by patients and whether they had to treat it more than once. It used self-reported online surveys of HAE patients in the United States recruited by HAEA, with sponsorship and analysis by KalVista.

These were patients who chose to treat their last attack, but it didn’t resolve with one dose of on-demand treatment. The results showed that after treatment, 32.7% didn’t have adequate control of their attack with one dose. This was the same for patients who were on on-demand treatment, as well as patients who were on long-term prophylaxis. When we look at the patients by when they treated and the likelihood of their attack returning, it turned out that if patients treated in less than an hour, only 26% of them had returned symptoms as opposed to 37% of patients who treated after the first hour. Regarding what they used to treat an attack, the likelihood of symptoms returning or persisting is greater with icatibant than with C1 inhibitor concentrate. Also, if they treated later instead of earlier, the likelihood of their symptoms returning is greater. We also examined how many subsequent treatments it took to resolve the attack. The majority responded to one extra dose, with only about 5% requiring a third dose to control symptoms.

This teaches us that the earlier you treat the attack, the more likely it is that it will respond and not return. The second piece is that it doesn’t seem to matter whether you’re on long-term prophylaxis or just on-demand.

13. Efficacy and Safety of Bradykinin B2 Receptor Antagonism with Deucrictibant Immediate-Release Capsule for Treatment of Hereditary Angioedema Attacks: Results of RAPIDe-1 Phase 2 Trial
Prof. Markus Magerl told the scientific audience that this paper addressed the unmet need for effective and well-tolerated on-demand oral therapies that reduce the treatment burden and enable prompt administration.

He said the study met all primary and secondary endpoints. The potential new medicine, deucrictibant, resulted in rapid onset of action, symptom relief, and resolution of HAE attacks, in addition to a substantial reduction in the use of rescue medication, and was well tolerated at all dose levels.

Prof. Magerl concluded that these trial results support further development of deucrictibant as a potential on-demand treatment for HAE attacks.

14. Anxiety Associated with On-demand Treatment for Hereditary Angioedema (HAE) Attacks
Global Perspectives had the opportunity to speak with Prof. Christiansen on the sidelines of the Conference. We asked her about her poster presentation and its implications:
The backdrop was individuals treated with either on-demand or on-demand plus long-term prophylaxis therapies. There were some adolescents involved, and every patient had to have had an attack that was treated with an on-demand therapy within three months. Similar to other research presented at this meeting, we found that, unfortunately, people were waiting too long. Once again, there was a correlation between an individual’s overall health and quality of life surrounding an attack and the delay in treating it. We found this was most extreme for adolescents.

The take-home message is that acute treatment of HAE is not good enough, with consequences in terms of quality of life and impression of general health. We would anticipate improving HAE if we addressed unmet needs for more therapies that are easy to use and reinforced the importance of treating promptly.

15. Diagnosis and Treatment of Patients with Hereditary Angioedema in Cuba
Dr. Consuelo Macías presented this research, which was developed to describe the epidemiological frequency, diagnosis, and treatments of patients with hereditary angioedema in Cuba.

The results from 42 HAE patients were reported, with Dr. Macías concluding that the frequency of HAE was higher in women than men and that regionally, there were more patients identified in the Villa Clara province of Cuba.