An Open-label Extension Trial to Evaluate the Long-term Safety of KVD900 (Sebetralstat) for On-Demand Treatment of Angioedema Attacks in Adolescent and Adult Patients With Hereditary Angioedema (HAE)

To join this study, you must have already participated in the KVD900-301 clinical trial. You need to have a confirmed diagnosis of Hereditary Angioedema (HAE) type I or II and have experienced at least two HAE attacks in the three months before joining this particular study.

Participants must be at least 12 years old. If you're currently taking other long-term medicines for HAE, your dosage needs to have been stable for at least three months (or six months if you're taking danazol). You should be able to swallow tablets whole and manage using an electronic diary.

You would not be able to join if you left the previous KVD900-301 study due to not following the rules, withdrawing your consent, or safety concerns. Also, if you have other types of angioedema (like acquired C1 inhibitor deficiency or HAE with normal C1-INH), have had a poor response to certain HAE treatments in the past, or are taking specific other medications (like attenuated androgens other than danazol), you would not be eligible.

If you join this study, you will continue to take KVD900 tablets (either 300 mg or 600 mg) to treat your HAE attacks as they happen. This study is designed to observe you over a longer period, so there isn't a fixed total duration mentioned, it will continue as long as necessary to gather long-term safety data. You will be asked to accurately record your HAE attacks and medication use in an electronic diary. You will have regular visits to the study clinic, where the study team will monitor your health, check for any side effects, and make sure the medication is working well for you. All study medications and assessments will be provided at no cost.