KalVista Pharmaceuticals Presents New Data Highlighting Patient Satisfaction with EKTERLY® (sebetralstat) and its Potential in Children Ages 2-11 at the ACAAI 2025 Annual Scientific Meeting

KONFIDENT-S participants who switched to sebetralstat reported being very or extremely satisfied

Interim results from KONFIDENT-KID show sebetralstat enables early, effective, safe treatment of HAE attacks in pediatric population and reveal higher attack frequency than previously believed

FRAMINGHAM, Mass. & SALISBURY, England--(BUSINESS WIRE)-- KalVista Pharmaceuticals, Inc. (Nasdaq: KALV) today announced new patient satisfaction and pediatrics data from its clinical studies of EKTERLY® (sebetralstat), the first and only oral on-demand treatment for hereditary angioedema (HAE), as well as physician and patient survey and consensus study data highlighting the substantial unmet need for safe, effective and easy-to-use on-demand treatments, presented at the American College of Allergy, Asthma & Immunology (ACAAI) 2025 Annual Scientific Meeting taking place from November 6–10, 2025.

Satisfaction with Sebetralstat for HAE Attacks in Patients Switching from Parenteral On-demand Treatments in KONFIDENT-S was presented by Maeve E. O'Connor, MD, board certified Allergist and Immunologist, Integrative Allergy & Immunology Care, Allergy, Asthma, & Immunology Research Institute, Charlotte, North Carolina.

• For 1,089 attacks treated with sebetralstat by patients in KONFIDENT-S who had switched from injectable on-demand treatments (icatibant, pdC1INH, rhC1INH), median treatment satisfaction score was 2 (very satisfied) on a 7-point Likert scale ranging from –3 (extremely dissatisfied) to 3 (extremely satisfied)
• Overall, 84% of attacks treated with sebetralstat were rated by participants as satisfied, very satisfied, or extremely satisfied, with the vast majority being very or extremely satisfied

“Patients living with HAE have consistently voiced the need for convenient, non-injectable treatment options,” said Dr. O’Connor. “The high satisfaction scores reported by patients who have successfully transitioned from injectable products to sebetralstat are extremely encouraging and speak directly to the profound impact of having a simple, effective, and reliable oral option readily available. Importantly, in clinical practice, a patient's desire to switch medication is often a direct measure of their unmet needs or dissatisfaction with the current regimen. Therefore, as satisfaction increases, the probability of switching decreases.”

Sebetralstat for On-demand Treatment of Hereditary Angioedema in Pediatric (2-11y) Patients: Interim Results from KONFIDENT-KID was presented by Adil Adatia, MD, FRCPC, Assistant Professor in the Department of Medicine at the University of Alberta in Edmonton, Alberta, and Director of the University of Alberta Angioedema Centre of Reference and Excellence (ACARE).

• Among 65 attacks treated in 26 children receiving weight-based dosing of sebetralstat in a proprietary oral disintegrating tablet (ODT) formulation as of June 6, 2025:
  • Participants treated a mean of 0.8 attacks per month
  • Caregivers or patients administered treatment in a median of 30 minutes
  • Median time to symptom relief (150 mg cohort) was 1.5 hours
• Sebetralstat was well tolerated with no serious or treatment-related adverse events, and no reports of difficulty swallowing 

“On-demand treatments for children with HAE currently require intravenous administration or subcutaneous injection and are associated with substantial administration burden, including logistical challenges, anxiety and pain,” said Dr. Adatia. “This can lead to denial of treatment or significant delays, resulting in lasting trauma for children with HAE and their caregivers. In the US, it’s even more challenging, as only intravenous pdC1INH is approved for children under 12 years of age. These interim results from KONFIDENT-KID are highly promising as they demonstrate that sebetralstat can achieve therapeutic exposure with a non-invasive, oral disintegrating formulation, which in turn can halt attack progression at an early stage and provide rapid relief. If approved, sebetralstat ODT for children would be a true breakthrough in HAE care.”

In two complementary presentations, A Delphi Consensus Study on the Barriers to On-Demand Treatment for Hereditary Angioedema Attacks presented by Dr. William Lumry and Hereditary Angioedema Patient and Expert Physician Alignment on a Novel Oral On-demand Therapy presented by Dr. Raffi Tachdjian—experts underscored the limitations of injectable on-demand therapies and growing preference for effective and convenient oral options that may reduce the treatment burden, improve early intervention, and increase adherence with HAE guidelines.¹

The international Delphi Consensus Study, involving 19 expert HAE clinicians, established a clear definition of “early treatment” as administration within 60 minutes of attack onset. The panelists identified major obstacles preventing patients from meeting this critical timeline, including parenteral administration burden and logistical challenges. The consensus strongly affirmed the unmet need for safe, effective, and convenient on-demand treatments that would empower patients to better adhere to treatment guidelines.

These expert findings were directly supported by a cross-sectional survey of adult HAE patients and their physicians. Key takeaways from this survey underscore the immediate need for a simple, oral solution:

• High delay rate: 86% of patients reported delaying or avoiding injectable on-demand treatment administration
• Injection aversion: Major reported reasons for delay included injection aversion (28%) and lack of privacy (27%)
• Strong oral preference: 89% of patients expressed a preference for an oral on-demand treatment

“Hereditary angioedema affects families across generations, and the possibility of an oral on-demand option for pediatrics is profoundly meaningful—not only for patients, but for their caregivers as well,” said Ben Palleiko, Chief Executive Officer of KalVista. “In KONFIDENT-KID, children with HAE experienced a higher frequency of attacks than previously appreciated. We believe this reflects an unmasking of the true disease burden that has long been hidden by the challenges of injectable treatments. The availability of sebetralstat could help ensure these attacks are treated earlier and more consistently, ultimately improving care for pediatric patients and their families. The data presented at ACAAI collectively underscore the transformative potential of EKTERLY, empowering patients of all ages to treat attacks early, effectively, and without injections. Building on the early success of the launch in patients 12 years and older, and as we continue to deliver EKTERLY globally, these findings add to the potential for EKTERLY to become the foundational therapy for HAE.”

Links to all presentations are available on the KalVista website under Publications.

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. Treatment guidelines recommend treating attacks as early as possible to prevent progression of swelling and shorten the time to attack resolution, and to consider treatment for all attacks, regardless of anatomic location or severity.

About EKTERLY® (sebetralstat)

EKTERLY (sebetralstat) is a novel plasma kallikrein inhibitor approved in the United States, European Union, United Kingdom and Switzerland for the treatment of acute attacks of hereditary angioedema (HAE) in people 12 years of age and older. EKTERLY is the first and only oral on-demand treatment for HAE, offering efficacious and safe treatment of attacks without the burden of injections. With ongoing studies exploring its use in children aged two to 11 and multiple regulatory applications under review in key global markets, EKTERLY has the potential to become the foundational therapy for HAE management worldwide. For more information, including the full U.S. Prescribing Information, visit EKTERLY.com.

About KalVista Pharmaceuticals, Inc.

KalVista is a global pharmaceutical company dedicated to delivering life-changing oral therapies for individuals affected by rare diseases with significant unmet needs. The KalVista team discovered and developed EKTERLY®—the first and only oral on-demand treatment for hereditary angioedema (HAE)—and continues to work closely with the global HAE community to improve treatment and care for this disease around the world. For more information about KalVista, please visit www.kalvista.com and follow us on LinkedIn, X, Facebook and Instagram.

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," "position," "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, information relating to our business and business plans, the success of our efforts to commercialize EKTERLY® (sebetralstat), our ability to successfully obtain foreign regulatory approvals for sebetralstat, our expectations about the safety and efficacy of sebetralstat, the timing of clinical trials and their results, our ability to commence clinical studies or complete ongoing clinical studies, including our KONFIDENT-S and KONFIDENT-KID trials, and the ability of EKTERLY to treat HAE. 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, 2025, 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.

¹ These independent consensus studies were funded through unrestricted educational grants from KalVista Pharmaceuticals, Inc. KalVista had no role in study design, data collection, analysis, or interpretation.

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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.