---
title: "Sebetralstat (Ekterly): The First Oral On-Demand Treatment for Hereditary Angioedema Attacks (October 2026 Update) | PepTracker Pro Blog"
url: https://peptrackerpro.com/blog/sebetralstat-ekterly-kvd900-kalvista-first-oral-on-demand-plasma-kallikrein-inhibitor-hereditary-angioedema-hae-acute-attack-treatment-bradykinin-kallikrein-kinin-contact-system-konfident-phase-3-nct05259917-konfident-s-konfident-kid-pediatric-fda-approved-october-1-2026
description: "Sebetralstat is the first pill that can stop a hereditary angioedema attack on demand. An oral plasma kallikrein inhibitor, it cut the median time to symptom relief to under two hours versus nearly seven on placebo - and in 2026 it posted positive pediatric data and a first-line guideline nod. Here is how it works, what KONFIDENT showed, and how it fits the HAE toolkit."
lang: en
---

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Research & Compounds

Research & Compounds

# Sebetralstat (Ekterly): The First Oral On-Demand Treatment for Hereditary Angioedema Attacks (October 2026 Update)

PepTracker Pro Research Team October 1, 2026 9 min read

## Table of Contents

- What sebetralstat is, in one line
- The problem it targets: the contact system and bradykinin
- Why an oral on-demand drug is a big deal
- What KONFIDENT showed
- Approval and how it is dosed
- How it fits: on-demand vs prophylaxis
- The pediatric expansion and the bottom line

## What sebetralstat is, in one line

Sebetralstat (brand name Ekterly; formerly KVD900) is a first-in-class, orally administered small-molecule inhibitor of plasma kallikrein - and the first and only pill approved to treat hereditary angioedema (HAE) attacks on demand, taken at the first sign of an attack in people aged 12 and older.

## The problem it targets: the contact system and bradykinin

Hereditary angioedema (HAE) is a rare genetic disease of sudden, recurrent swelling - of the hands, feet, face, abdomen and, most dangerously, the airway. The root cause in most patients is a shortage or malfunction of C1-esterase inhibitor (C1-INH), the body's natural brake on the plasma contact system. Without that brake the cascade runs unchecked: Factor XII is activated to FXIIa; FXIIa converts prekallikrein into active plasma kallikrein; kallikrein cleaves high-molecular-weight kininogen; and that releases bradykinin, the peptide that makes blood vessels leaky and produces the painful, sometimes life-threatening edema of an HAE attack. Sebetralstat works at the kallikrein step, directly blocking the enzyme that generates bradykinin - so an attack already under way is halted and reversed.

## Why an oral on-demand drug is a big deal

The target itself is not new - plasma kallikrein is also hit by the injectable antibody lanadelumab and the oral prophylactic berotralstat. What is new is the role and the route. Until sebetralstat, every on-demand (rescue) option for an HAE attack was given by subcutaneous injection (icatibant, ecallantide) or intravenous infusion (C1-esterase-inhibitor concentrates). That burden leads many patients to delay or skip treating milder attacks, even though treating early produces better outcomes. Sebetralstat removes the needle from the moment of greatest urgency: it is a tablet a patient can carry and swallow the instant symptoms begin, which is designed to get more attacks treated, and treated sooner.

## What KONFIDENT showed

The pivotal evidence is KONFIDENT (NCT05259917), described by its sponsor as the largest clinical trial ever conducted in HAE: 136 adult and adolescent patients at 66 sites across 20 countries. It was a randomized, double-blind, placebo-controlled, event-driven crossover trial in which each patient treated up to three eligible attacks, with up to two doses of study drug per attack, using sebetralstat 300 mg, sebetralstat 600 mg or placebo. The primary endpoint was the time to the beginning of symptom relief. Sebetralstat shortened that median time to 1.61 hours at 300 mg (p<0.0001) and 1.79 hours at 600 mg (p=0.0013), compared with 6.72 hours on placebo - roughly a five-hour head start. Secondary endpoints also favored the drug: faster time to a reduction in attack severity and faster time to complete attack resolution. It was well tolerated, with treatment-related adverse-event rates of about 2% on either dose versus about 5% on placebo and no serious adverse events. The results were published in the New England Journal of Medicine in 2024, and the KONFIDENT-S open-label extension has since reported durable, real-world relief - including for mucosal attacks and for breakthrough attacks in patients already on prophylaxis.

## Approval and how it is dosed

Regulators moved quickly. The U.S. FDA approved Ekterly on July 7, 2025 for the on-demand treatment of acute HAE attacks in adults and pediatric patients aged 12 and older - making it the first and only oral on-demand therapy for the disease. The European Commission and Swissmedic followed on September 19, 2025 (for adults and adolescents aged 12 and older), and the UK MHRA also approved it. The approved regimen is simple: 600 mg (two 300 mg tablets) taken at the earliest recognition of an attack, with a repeat 600 mg dose allowed at least 3 hours later if the response is inadequate or symptoms recur or worsen, up to a maximum of 1200 mg in any 24-hour period. As an oral drug it is subject to drug-drug interactions and should be taken exactly as prescribed; use in pregnancy and breastfeeding has not been established.

## How it fits: on-demand vs prophylaxis

Sebetralstat is a rescue therapy, not a preventive one - it stops attacks once they start and does not reduce how often they happen. It sits alongside the other on-demand options (icatibant and ecallantide by injection, C1-esterase-inhibitor concentrates by injection or infusion), now adding a needle-free, carry-anywhere choice. It is separate from, and complementary to, the long-term prophylactic drugs that aim to prevent attacks in the first place: the Factor XIIa antibody garadacimab (Andembry), the prekallikrein-lowering antisense drug donidalorsen (Dawnzera), the anti-kallikrein antibody lanadelumab (Takhzyro), the oral kallikrein inhibitor berotralstat (Orladeyo) and C1-INH replacement. Many patients on prophylaxis still have breakthrough attacks, so a convenient oral rescue therapy is useful across the spectrum of HAE care.

## The pediatric expansion and the bottom line

The newest chapter is about younger children. On March 30, 2026 KalVista reported positive interim Phase 3 results from KONFIDENT-KID, a study of sebetralstat in children aged 2 to 11 using a purpose-built orally disintegrating tablet with weight-based dosing. Enrollment was expanded from a planned 24 to roughly 36 children across seven countries and finished about a year ahead of schedule; an interim analysis of 172 attacks in 33 participants showed a median of 25 minutes from attack onset to treatment, 67% of attacks treated within an hour, and in the 150 mg group a median 1.5 hours to the beginning of symptom relief - with no serious or treatment-related adverse events and no difficulty swallowing. KalVista said it planned to file a U.S. new drug application in the second half of 2026, with a potential launch in 2027; the under-12 indication is not yet approved. Separately, a 2026 international pediatric HAE guideline named sebetralstat a first-line on-demand option for adolescents aged 12 and older. The bottom line for readers: sebetralstat is an FDA-approved, first-in-class oral pill that stops HAE attacks by blocking plasma kallikrein, is a rescue - not a preventive - therapy, and is a prescription medicine for a specific rare disease, not a supplement or research chemical. Anyone considering it should do so with an HAE specialist, as part of a plan that still includes emergency care for airway attacks.

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## Citations

1. [1] Oral Sebetralstat for On-Demand Treatment of Hereditary Angioedema Attacks (KONFIDENT) - New England Journal of Medicine (2024) Source (https://pubmed.ncbi.nlm.nih.gov/38819658/)
2. [2] KalVista Reports Phase 3 KONFIDENT Trial Meets All Endpoints for Sebetralstat as First Oral On-demand Therapy for HAE - KalVista (2024) Source (https://ir.kalvista.com/news-releases/news-release-details/kalvista-pharmaceuticals-reports-phase-3-konfident-trial-meets/)
3. [3] Sebetralstat FDA-Approved as First Oral, On-Demand Treatment for Hereditary Angioedema - HCPLive (July 2025) Source (https://www.hcplive.com/view/sebetralstat-fda-approved-as-first-oral-on-demand-for-hereditary-angioedema)
4. [4] A Study of Sebetralstat (KVD900) for On-Demand Treatment of Angioedema Attacks (KONFIDENT) - ClinicalTrials.gov NCT05259917 Source (https://clinicaltrials.gov/study/NCT05259917)
5. [5] KalVista Announces European Commission and Swissmedic Approval of EKTERLY (sebetralstat) - KalVista (September 19, 2025) Source (https://ir.kalvista.com/news-releases/news-release-details/kalvista-pharmaceuticals-announces-european-commission-and/)
6. [6] KalVista Announces Positive Interim Phase 3 Data From KONFIDENT-KID Trial of EKTERLY (sebetralstat) for Children Aged 2-11 - KalVista (March 30, 2026) Source (https://kalvista.gcs-web.com/news-releases/news-release-details/kalvista-pharmaceuticals-announces-positive-interim-phase-3-data)
7. [7] Pediatric HAE Guideline Recommends Sebetralstat as First-Line Therapy for Adolescents 12 and Older - HCPLive (2026) Source (https://www.hcplive.com/view/pediatric-hae-guideline-recommends-sebetralstat-first-line-therapy)
8. [8] Sebetralstat (Ekterly) Dosage Guide - Drugs.com Source (https://www.drugs.com/dosage/sebetralstat.html)

**Disclaimer:** This article is for educational purposes only and does not constitute medical advice. Always consult a licensed healthcare provider. Read full research disclaimer → (https://peptrackerpro.com/research-disclaimer)

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