Last reviewed 2026-04-23 · How we verify

BCX4161

BCX4161 is a small molecule inhibitor of the C1 inhibitor of the complement system.

BCX4161 is a small molecule inhibitor of the C1 inhibitor of the complement system. Used for Hereditary angioedema.

At a glance

Mechanism of action

BCX4161 works by inhibiting the C1 inhibitor, which is a key component of the classical pathway of the complement system. This inhibition leads to the activation of the complement system, which helps to eliminate pathogens and damaged cells. By modulating the complement system, BCX4161 may help to reduce inflammation and improve immune function.

Approved indications

• Hereditary angioedema

Common side effects

• Nausea
• Headache
• Fatigue

Key clinical trials

• A Study of Avoralstat In Participants With Diabetic Macular Edema (PHASE1)
• 12-Week Safety and Efficacy Study of BCX4161 as an Oral Prophylaxis Against HAE Attacks (PHASE2, PHASE3)
• Open-label, Long-term Safety Study of Avoralstat in Subjects With Hereditary Angioedema (PHASE3)
• Study to Determine How BCX4161 is Metabolized and Eliminated by the Body (PHASE1)
• Safety and Efficacy of Oral BCX4161 as a Prophylactic Treatment for HAE (PHASE2)
• A Study of the Relative Bioavailability of a New Formulation of BCX4161 and the Effect of Food on BCX4161 (PHASE1)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• BCX4161 CI brief — competitive landscape report
• BCX4161 updates RSS · CI watch RSS
• BioCryst Pharmaceuticals portfolio CI