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C1 inhibitor (human) [C1 INH]

Shire · FDA-approved active Biologic

C1 inhibitor (human) is a plasma protein that regulates the initial step of the classical complement cascade by inhibiting C1s protease activity.

C1 inhibitor (human) is a plasma protein that regulates the initial step of the classical complement cascade by inhibiting C1s protease activity. Used for Hereditary angioedema (HAE) — acute attack treatment, Hereditary angioedema (HAE) — prophylaxis of recurrent attacks.

At a glance

Generic nameC1 inhibitor (human) [C1 INH]
Also known asCINRYZE, C1 esterase inhibitor (human)
SponsorShire
Drug classComplement inhibitor / Serine protease inhibitor
TargetC1s protease / Classical complement pathway
ModalityBiologic
Therapeutic areaImmunology / Rare disease
PhaseFDA-approved

Mechanism of action

C1 INH is a serine protease inhibitor that controls activation of the complement system's classical pathway by binding to and inactivating C1s. By suppressing this early cascade step, it prevents excessive generation of inflammatory mediators (C3a, C5a) and bradykinin, thereby reducing pathological inflammation and angioedema. This mechanism is particularly relevant in hereditary angioedema (HAE), where C1 INH deficiency or dysfunction leads to uncontrolled complement and contact system activation.

Approved indications

Common side effects

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