Ekterly (sebetralstat)
An approved treatment for Hereditary Angioedema.
The same compound appears under different names depending on the context. Here is how to identify Sebetralstat wherever you encounter it, plus the key facts at a glance.
- Generic name
- Sebetralstat
- Brand name
- Ekterly
- Development code
- KVD900
- Drug class
- Plasma kallikrein inhibitor (oral, on-demand)
- Manufacturer
- KalVista Pharmaceuticals
- How it's taken
- One 600 mg dose, 2 tablets, by mouth at the earliest recognition of an attack.
The first pill for treating a hereditary angioedema attack as it happens. Before Ekterly, every on-demand HAE treatment was an injection or infusion. Approved in July 2025 for patients 12 and older, with a median 2 hours to the start of symptom relief.
Where Sebetralstat fits
The first oral on-demand option in HAE, where every prior acute treatment was injected or infused. It does not replace prophylaxis; it replaces the injection a patient reaches for when an attack begins.
How Sebetralstat works
During an HAE attack, plasma kallikrein is actively cleaving kininogen to release bradykinin, and the swelling grows as long as that continues. Sebetralstat is a small molecule that binds plasma kallikrein and reversibly blocks it, cutting off the bradykinin supply so the attack stops progressing and symptoms begin to ease. Taken as a pill at the first sign of an attack, it reaches the blood fast enough to matter; the label also notes it interrupts the feedback loop by which kallikrein activates more of itself.
Mechanism: Oral plasma kallikrein inhibitor taken at the first sign of a hereditary angioedema attack to stop the bradykinin release that drives the swelling
Side effects and safety
- Avoid with strong CYP3A4 inhibitors and with strong or moderate CYP3A4 inducers; use a 300 mg dose with moderate CYP3A4 inhibitors or moderate liver impairment; avoid in severe liver impairment
- Severe throat attacks were not studied in the trial; an attack that threatens the airway is an emergency regardless
The label lists no boxed warning and the most common reaction, in at least 2% of patients, was headache. Avoid it with strong CYP3A4 inhibitors and with strong or moderate CYP3A4 inducers. A lower 300 mg dose is used with moderate CYP3A4 inhibitors or moderate liver impairment, and it should be avoided in severe liver impairment. Suspected reactions can be reported to KalVista at 1-855-258-4782.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Sebetralstat
One 600 mg dose, 2 tablets, by mouth at the earliest recognition of an attack. A second 600 mg dose may be taken at least 3 hours later if the response is inadequate or symptoms worsen or return. The maximum is 1,200 mg in any 24 hours. It is carried by the patient and taken wherever the attack starts.
Availability and cost
Only available as the brand-name product.
An oral small molecule dispensed per attack rather than on a schedule, which changes the cost conversation from a monthly figure to a per-episode one. No injection supplies, no refrigeration, no infusion setting.
Help paying for Ekterly
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Insurance and case manager help
A dedicated Care Manager helps with insurance coverage, checks eligibility for financial support, and works with your specialty pharmacy.
The official page does not say who qualifies. Ask the program. · source - Copay help
Eligible commercially insured patients may pay as little as $0; program maximum applies. Medicare, Medicaid, TRICARE, VA and other government plans are not eligible.
For: private insurance · source - Bridge or quick-start supply
QuickStart Program: temporary treatment options for new patients while waiting for a coverage decision.
The official page does not say who qualifies. Ask the program. · source
Good to know: Official pages do not describe a free-drug program for uninsured patients; ask KalVista Cares. Mon-Fri 8:30 AM-8 PM ET.
- From a charity · The Assistance FundHereditary Angioedema (HAE) fundOpen
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “OPEN — Accepting New Patients. TAF is currently accepting new patient enrollments for this program.” - From a charity · US Hereditary Angioedema AssociationChris Whalen HAEA Compassion Fund fundApply directly
Pays for: Travel to care for HAE-related reasons (e.g. seeing a specialist).
The foundation says: “Status not shown on page”
Clinical trial results
The KONFIDENT trial (NCT05259917) was a double-blind, placebo-controlled, 3-way crossover study in which 110 patients aged 12 and older treated 264 attacks, each patient treating attacks with 600 mg, 300 mg and placebo in turn. The primary endpoint was time to the beginning of symptom relief, defined as feeling at least a little better at 2 consecutive checks within 12 hours. The median for 600 mg was 2.0 hours (95% CI 1.5 to 2.8); fewer than half of placebo-treated attacks reached that point within 12 hours, so no placebo median could be calculated. In the 600 mg group, 38% of patients took a second dose within 12 hours. Severe laryngeal attacks were excluded from the trial, which matters for the one kind of attack that can kill.
Development history
Developed by KalVista as KVD900 and approved by the FDA on July 3, 2025, the first oral on-demand treatment for HAE attacks. It arrived between 2 new prophylactic approvals, Andembry in June and Dawnzera in August 2025.
Explore Hereditary Angioedema trials
Other Hereditary Angioedema treatments
Common questions about Sebetralstat
▸What is Sebetralstat (Ekterly)?
The first pill for treating a hereditary angioedema attack as it happens. Before Ekterly, every on-demand HAE treatment was an injection or infusion. Approved in July 2025 for patients 12 and older, with a median 2 hours to the start of symptom relief.
▸How does Sebetralstat work?
During an HAE attack, plasma kallikrein is actively cleaving kininogen to release bradykinin, and the swelling grows as long as that continues. Sebetralstat is a small molecule that binds plasma kallikrein and reversibly blocks it, cutting off the bradykinin supply so the attack stops progressing and symptoms begin to ease. Taken as a pill at the first sign of an attack, it reaches the blood fast enough to matter; the label also notes it interrupts the feedback loop by which kallikrein activates more of itself.
▸What are the side effects of Sebetralstat?
The label lists no boxed warning and the most common reaction, in at least 2% of patients, was headache. Avoid it with strong CYP3A4 inhibitors and with strong or moderate CYP3A4 inducers. A lower 300 mg dose is used with moderate CYP3A4 inhibitors or moderate liver impairment, and it should be avoided in severe liver impairment. Suspected reactions can be reported to KalVista at 1-855-258-4782.
▸How is Sebetralstat taken?
One 600 mg dose, 2 tablets, by mouth at the earliest recognition of an attack. A second 600 mg dose may be taken at least 3 hours later if the response is inadequate or symptoms worsen or return. The maximum is 1,200 mg in any 24 hours. It is carried by the patient and taken wherever the attack starts.
▸Is Sebetralstat FDA approved?
Yes, Sebetralstat (Ekterly) is FDA approved (2025) for the treatment of Hereditary Angioedema.
▸What is Ekterly approved for?
Ekterly (sebetralstat) is approved to treat acute hereditary angioedema attacks in adults and children aged 12 and older. The FDA approved it on July 3, 2025 as the first oral on-demand treatment for HAE. It is taken when an attack starts, not to prevent attacks.
▸How fast does Ekterly work?
In the KONFIDENT trial, the median time to the beginning of symptom relief after a 600 mg dose was 2.0 hours, with a confidence interval of 1.5 to 2.8 hours. Fewer than half of placebo-treated attacks reached that point within 12 hours. About 38% of patients took a second dose.
▸How is Ekterly taken?
Two 300 mg tablets (600 mg total) by mouth at the earliest sign of an attack. A second 600 mg dose can be taken at least 3 hours later if needed, up to a maximum of 1,200 mg in 24 hours. It is meant to be carried and taken wherever an attack begins.
▸Does Ekterly work for throat attacks?
Severe laryngeal attacks were excluded from the pivotal trial, so there is no trial evidence for them. Any attack that threatens the airway is an emergency that needs immediate medical care regardless of what has been taken.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- KalVista / FDA · 2026-04. EKTERLY (sebetralstat) tablets, for oral use: US Prescribing Information. https://dailymed.nlm.nih.gov/dailymed/search.cfm?labeltype=all&query=EKTERLY
- U.S. Food and Drug Administration · 2025-07-03. EKTERLY approval, NDA 219301, July 3 2025. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=219301
- ClinicalTrials.gov. Efficacy and Safety of Sebetralstat for On-Demand Treatment of HAE Attacks (KONFIDENT). https://clinicaltrials.gov/study/NCT05259917