FRAMINGHAM, Mass.– KalVista Pharmaceuticals reported new clinical data showing high patient satisfaction and evolving treatment patterns with EKTERLY (sebetralstat), its oral on-demand therapy for hereditary angioedema, during presentations at leading allergy and immunology conferences.
The company presented findings from its sebetralstat clinical program at the 2026 American Academy of Allergy, Asthma & Immunology Annual Meeting and the Western Society of Allergy, Asthma & Immunology 63rd Annual Scientific Session. The data suggest that access to an oral therapy reduced barriers to treatment, supported earlier intervention and was associated with improved response rates.
“The data presented at AAAAI and WSAAI reinforce the importance of treating HAE attacks early, which is consistently associated with improved outcomes,” said Ben Palleiko, CEO of KalVista. “In the KONFIDENT-S open-label extension, we are observing sustained effectiveness and high patient satisfaction with repeated use of sebetralstat, along with meaningful changes in treatment behavior, including treating the majority of attacks, early intervention, and preference for an oral option. Together, these findings support our belief that EKTERLY has the potential to transform how HAE is managed and deliver sustained real-world benefit for people living with HAE.”
Data from the KONFIDENT-S open-label study showed that, as of July 9, 2025, 2,464 hereditary angioedema attacks had been treated with sebetralstat. Among the first 30 attacks per participant, the need for a second dose occurred in 19.3% of attacks and declined over time. Use of conventional injectable treatments within 12 hours occurred in 5.1% of attacks and also decreased with repeated use. Patient satisfaction remained high, with 83.1% of sebetralstat-treated attacks rated as satisfied or better on a seven-point scale.
Additional data presented at AAAAI indicated that nearly all reported attacks were treated, with 98.1% managed using either oral sebetralstat or conventional injectable therapy. Of those, 82.1% were treated with sebetralstat, suggesting strong patient preference regardless of attack severity or location. Use of injectable treatments declined over successive attacks, while sebetralstat use increased, indicating a shift toward oral therapy when available.
“The longitudinal data from KONFIDENT-S show a meaningful shift in HAE management by patients,” said Marc Riedl, MD, who presented study findings. “With oral on-demand therapy, barriers to treatment of attacks are reduced, including challenges that may exist with injectable medications, potentially facilitating treatment of more attacks. What is also encouraging is that as patients gained treatment experience, we observed a decreasing trend in the need for both second doses and conventional injectable on-demand therapies. This change in treatment patterns occurred with high levels of patient satisfaction, which was durable over the large number of attacks treated. Overall, these trends suggest that sebetralstat may offer an on-demand treatment option that could empower patients to treat disabling HAE symptoms more frequently, and potentially more efficiently, over time.”
Separate analyses from placebo-controlled trials examined drivers of response and found that time to treatment was the strongest predictor of symptom relief. Treating attacks within 30 minutes of onset was associated with a significantly higher likelihood of achieving symptom relief within 12 hours, with modeling suggesting nearly 90% of subjects could experience relief when treated early.
“The findings from our modeling and simulation analysis reinforce that time to treatment is the most robust driver of clinical success in HAE,” said Jonathan Bernstein, MD, FAAAAI. “When patients are able to administer an oral dose of sebetralstat within 30 minutes of an attack, the probability of achieving symptom relief within 12 hours is nearly 90%. What is particularly striking is that early intervention proved more predictive of success than the location or severity of the attack. These data emphasize that an oral on-demand therapy like sebetralstat doesn’t just offer convenience, it provides a clinical advantage by allowing patients to treat early and consistently to achieve better outcomes.”
Hereditary angioedema is a rare genetic disorder caused by deficiency or dysfunction of the C1 esterase inhibitor protein, leading to recurrent and potentially life-threatening swelling attacks. Clinical guidelines recommend early treatment of all attacks to prevent progression and shorten duration.
EKTERLY (sebetralstat) is approved in multiple global markets as the first oral on-demand treatment for acute hereditary angioedema attacks in patients aged 12 and older. KalVista said it plans to pursue regulatory expansion to younger pediatric populations and additional markets.
