KalVista Pharmaceuticals Shares Latest Sebetralstat Findings at the American Academy of Allergy, Asthma & Immunology 2025 Annual Meeting

Rhea-AI Summary

KalVista Pharmaceuticals (KALV) presented new data for sebetralstat in treating hereditary angioedema (HAE) attacks at the AAAAI/WAO 2025 Joint Congress. The KONFIDENT-S study showed promising results for laryngeal HAE attacks, with patients achieving:

- Median treatment time of 11.5 minutes after attack onset
- Median symptom relief time of 1.27 hours
- 96% effectiveness with single dose
- No difficulty swallowing tablets reported

For adolescent patients, pooled analysis from KONFIDENT/KONFIDENT-S studies (149 attacks) demonstrated:
- Median treatment time of 4 minutes vs. traditional 3+ hours
- Safety and efficacy comparable to adults
- No serious adverse events

If approved, sebetralstat would become the first oral on-demand treatment for HAE attacks, potentially transforming HAE management, particularly for vulnerable populations like adolescents and those experiencing laryngeal attacks.

Positive

• First potential oral on-demand HAE treatment vs. current injectables
• Fast median treatment time: 11.5 mins for laryngeal attacks
• 96% single-dose effectiveness in symptom relief
• Strong safety profile with no serious adverse events
• Significantly faster treatment time in adolescents (4 mins vs 3+ hours)

Negative

• None.

Insights

Pharmaceutical Clinical Trials Specialist

KalVista's latest data on sebetralstat presents compelling evidence for this oral HAE treatment's potential to address significant unmet needs in a market currently dominated by injectable therapies. The data specifically addresses two critical patient subgroups - those with life-threatening laryngeal attacks and adolescents - where treatment speed is particularly crucial.

For laryngeal attacks, which can rapidly progress to airway obstruction, patients treated with sebetralstat achieved a median time to symptom relief of just 1.27 hours after treating within 11.5 minutes of onset. This addresses a critical medical need, as laryngeal attacks can be fatal if not treated promptly. Current injectable treatments often face delays, with U.S. survey data showing mean treatment times of 2.5 hours - a potentially dangerous gap that sebetralstat's oral administration could help close.

For adolescents, who face unique treatment challenges, the median time to treatment was only 4 minutes versus over 3 hours reported in survey data for current options. This remarkable improvement in treatment time demonstrates sebetralstat's potential to transform care for younger patients who currently have no FDA-approved self-administered options.

These findings strongly position sebetralstat as a potential first-in-class oral therapy that could fundamentally change HAE attack management, potentially expanding the market by addressing barriers to prompt treatment inherent with injectable therapies. The safety profile appears consistent with previous reports, with no serious adverse events in adolescents and no reported difficulties swallowing tablets even during laryngeal attacks.

Orphan Drug Market Analyst

KalVista's sebetralstat data presentation at AAAAI reinforces the drug's potential to disrupt the HAE treatment landscape. The orphan disease space typically commands premium pricing, and HAE is a prime example with current therapies costing tens of thousands annually per patient. Sebetralstat could potentially become the first oral on-demand therapy in a market where all current attack treatments require injection.

The CEO's statement positioning sebetralstat as a potential "foundational therapy for HAE management" signals KalVista's strategic ambition to capture significant market share. The interim KONFIDENT-S study results address two critical commercial considerations: laryngeal attacks (the most dangerous subtype) and the adolescent population (an underserved segment).

The data showing rapid treatment times (11.5 minutes for laryngeal attacks and 4 minutes for adolescents) highlights a key differentiator from current options. For perspective, survey data presented at the same conference indicated current treatments take a median of 3 hours for adolescents.

While this data represents an interim analysis rather than full results, the consistency of findings across different attack types and age groups strengthens sebetralstat's clinical profile. The presentation of this specialized data at a major medical conference, focused on patient populations with heightened unmet needs, suggests KalVista is strategically building its case for both regulatory approval and market adoption through targeted evidence generation.

–Sebetralstat enabled prompt treatment of laryngeal HAE attacks with median time of 1 hour and 16 minutes to onset of symptom relief–

–Pooled data analysis showed adolescents treated with sebetralstat in median 4 minutes compared to over 3 hours in surveys –

CAMBRIDGE, Mass. & SALISBURY, England--(BUSINESS WIRE)-- KalVista Pharmaceuticals, Inc. (Nasdaq: KALV) today announced the presentation of novel sebetralstat data related to laryngeal hereditary angioedema (HAE) attacks and adolescents with HAE at the American Academy of Allergy, Asthma & Immunology (AAAAI) / World Allergy Organization (WAO) 2025 Joint Congress taking place in San Diego, CA from February 28–March 3, 2025.

“The growing body of data from the KONFIDENT-S study consistently demonstrate that sebetralstat enabled early treatment and fast symptom relief from HAE attacks, regardless of age, attack location, or severity,” said Ben Palleiko, CEO of KalVista. “This is especially critical for vulnerable populations, such as those experiencing laryngeal attacks or adolescents whose only approved options are injectable on-demand treatments. Sebetralstat, if approved, would be the first oral on-demand treatment for HAE attacks, with the potential to address some of the most significant unmet needs in HAE and become the foundational therapy for HAE management."

Effectiveness of Sebetralstat for the On-demand Treatment of Laryngeal Hereditary Angioedema Attacks: Interim Analysis from KONFIDENT-S was presented by Jonathan Bernstein, MD, FAAAAI, Professor of Clinical Medicine in the Department of Internal Medicine, Division of Allergy and Immunology at the University of Cincinnati College of Medicine; Partner at Bernstein Allergy Group and Clinical Research Center.

• 32 laryngeal attacks were treated with sebetralstat (September 14, 2024 cutoff)
• Median time to treatment with sebetralstat: 11.5 minutes after attack onset
• Median time to beginning of symptom relief: 1.27 hours
• 96% of those achieving beginning of symptom relief within 12 hours did so with a single dose
• No reports of difficulty swallowing film-coated tablet

“Laryngeal attacks are often unpredictable and can progress rapidly, potentially leading to asphyxiation,” said Dr. Bernstein. “Any attack involving the larynx must be considered a medical emergency and treated as quickly as possible after onset before symptoms worsen. Despite this, recent U.S. survey data showed the mean time to treatment for laryngeal attacks with injectable on-demand therapies was 2.5 hours. Patients in the KONFIDENT-S study treated their attacks with sebetralstat, with a median time to treatment of just under 12 minutes, followed by symptom relief with a median time of 1 hour and 16 minutes. These results show that in the time it takes many patients to decide whether to treat, prepare and administer an injectable on-demand treatment, most patients in KONFIDENT-S were already experiencing symptom relief. If approved, sebetralstat could represent a therapeutic advance over injectables.”

On-demand Treatment of Hereditary Angioedema Attacks with Sebetralstat In Adolescents: Pooled Analysis From KONFIDENT And KONFIDENT-S was presented by Professor Danny Cohn, Head of the HAE clinic at Amsterdam University Medical Center (UMC), University of Amsterdam, Netherlands.

• 149 attacks were treated with sebetralstat across KONFIDENT/KONFIDENT-S (September 14, 2024 cutoff)
• Median time from attack onset to treatment: 4 minutes
• Safety and efficacy consistent with adults; no serious adverse events or adverse events leading to discontinuation

"Adolescents face considerable challenges in treating their HAE attacks, with substantially longer delays to treatment than adults. This challenge is compounded in the U.S., where the only approved treatments options require either intravenous administration or subcutaneous administration by an HCP,” said Dr. Cohn. “The pooled data from the KONFIDENT and KONFIDENT-S studies show that adolescents administered sebetralstat in a median of 4 minutes after attack onset, which compares favorably to a median of 3 hours and mean of 5.2 hours based on international survey data that was presented at AAAAI by Dr. Paula Busse titled, ‘Burden of Injectable On-Demand Treatment for Hereditary Angioedema Attacks in Adolescents’. Importantly, the safety and effectiveness of sebetralstat were consistent with what was observed in adults. The portability and ease of administration of sebetralstat, along with the elimination of injection-site reactions and associated anxiety, has the potential to bring transformative change to this underserved patient population."

Links to all posters and presentations shared at AAAAI can be found on the KalVista website under Publications.

About Sebetralstat

Sebetralstat is an investigational, novel oral plasma kallikrein inhibitor for the treatment of hereditary angioedema (HAE). We have filed multiple regulatory applications seeking approval of sebetralstat as the first oral, on-demand treatment for HAE in individuals aged 12 and older, with ongoing studies exploring its use in children aged 2 to 11. If approved, sebetralstat has the potential to become the foundational therapy for HAE management worldwide.

About Hereditary Angioedema

Hereditary angioedema (HAE) is a rare genetic disease resulting in deficiency or dysfunction in the C1 esterase inhibitor (C1INH) protein and subsequent uncontrolled activation of the kallikrein-kinin system. People living with HAE experience painful and debilitating attacks of tissue swelling in various locations of the body that can be life-threatening depending on the area affected. All currently approved on-demand treatment options require either intravenous or subcutaneous administration.

About KalVista Pharmaceuticals, Inc.

KalVista Pharmaceuticals, Inc., is a global biopharmaceutical company dedicated to developing and delivering life-changing oral therapies for individuals affected by rare diseases with significant unmet needs. Our lead investigational product is sebetralstat, a novel, oral, on-demand treatment for hereditary angioedema (HAE). Sebetralstat is under regulatory review by the U.S. FDA, with a PDUFA goal date of June 17, 2025. In addition, we have completed Marketing Authorization Applications for sebetralstat to the European Medicines Agency and multiple other global regulatory authorities.

For more information about KalVista, please visit www.kalvista.com or follow us on social media at @KalVista and LinkedIn.

Forward-Looking Statements

This press release contains "forward-looking" statements within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by words such as: "anticipate," "intend," "plan," "goal," "seek," "believe," "project," "estimate," "expect," "strategy," "future," "likely," "may," "should," "will" and similar references to future periods. These statements are subject to numerous risks and uncertainties that could cause actual results to differ materially from what we expect. Examples of forward-looking statements include, among others, timing or outcomes of communications with the FDA, our expectations about safety and efficacy of our product candidates and timing of clinical trials and its results, our ability to commence clinical studies or complete ongoing clinical studies, including our KONFIDENT-S and KONFIDENT-KID trials, and to obtain regulatory approvals for sebetralstat and other candidates in development, the success of any efforts to commercialize sebetralstat, the ability of sebetralstat and other candidates in development to treat HAE or other diseases, and the future progress and potential success of our oral Factor XIIa program. Further information on potential risk factors that could affect our business and financial results are detailed in our filings with the Securities and Exchange Commission, including in our annual report on Form 10-K for the year ended April 30, 2024, our quarterly reports on Form 10-Q, and our other reports that we may make from time to time with the Securities and Exchange Commission. We undertake no obligation to publicly update any forward-looking statement, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise.

View source version on businesswire.com: https://www.businesswire.com/news/home/20250303160255/en/

Ryan Baker

Head, Investor Relations

(617) 771-5001

ryan.baker@kalvista.com

Molly Cameron

Director, Corporate Communications

(978) 339-3378

molly.cameron@kalvista.com

Source: KalVista Pharmaceuticals, Inc.

FAQ

What are the key efficacy results for sebetralstat in treating laryngeal HAE attacks according to KONFIDENT-S data?

KALV's sebetralstat showed median treatment time of 11.5 minutes post-attack, with symptom relief beginning at 1.27 hours. 96% of patients achieved relief within 12 hours with a single dose.

How does sebetralstat's treatment time in adolescents compare to current HAE treatments?

KALV's sebetralstat showed median treatment time of 4 minutes in adolescents, compared to over 3 hours with traditional injectable treatments.

What makes KALV's sebetralstat unique in the HAE treatment landscape?

Sebetralstat would be the first oral on-demand treatment for HAE attacks, offering an alternative to current injectable-only options.

What were the safety findings for KALV's sebetralstat in adolescent HAE patients?

Sebetralstat showed safety and efficacy consistent with adults, with no serious adverse events or discontinuations reported in adolescent patients.