Complement

Ciprocopan (NXP100)

Complement Factor B Inhibitor

Ciprocopan is a small molecule for oral, once daily administration that inhibits Factor B, a critical protease within the alternative pathway of the complement cascade. Factor B is a validated target in several complement-mediated diseases.

Oral, once daily
Approved in China for PNH

How it works

Factor B inhibition blocks the activation of the alternative pathway and the amplification loop of the complement pathway. Ciprocopan is the first globally approved once-daily oral Complement Factor B inhibitor (approved in China), designed to provide comprehensive control of both intravascular and extravascular hemolysis, offering a convenience advantage for patients who need continuous, life-long treatment. The only FDA-approved Factor B inhibitor, Fabhalta® (iptacopan), is taken orally twice per day.

Classical pathwayPreserved

Lectin pathwayPreserved

Alternative pathwayFactor BCiprocopan inhibits Factor B

C3 convertase: cleavage of C3 into C3b

C5 convertaseC5 inhibitors act here (e.g., eculizumab)

Membrane attack complex

Simplified illustration. Factor B inhibition acts upstream in the cascade, proximal, and blocks the amplification loop, while terminal complement inhibitors, such as anti-C5s, act at the final steps of the pathway.

Clinical data

Paroxysmal Nocturnal Hemoglobinuria (PNH)

In a Phase 3 head-to-head study in 73 treatment-naive patients with PNH, ciprocopan was superior to Soliris® (eculizumab) on the primary and key secondary endpoints, with 59.5% of patients on ciprocopan achieving hemoglobin of at least 12 g/dL without a transfusion, compared with 8.3% on eculizumab (p < 0.001). A second Phase 3 study in 36 patients with PNH and persistent anemia after treatment with a C5 inhibitor also met the primary and key secondary endpoints.

Immunoglobulin A Nephropathy (IgAN)

In a randomized, placebo-controlled Phase 2 study in IgAN, ciprocopan reduced proteinuria by 45.3% versus placebo at week 12, growing to 57.7% at week 24.

These studies were conducted by Haisco Pharmaceutical Group in China.

Back to pipeline

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