Expert: PEGylated cyclic peptide that binds C3 and its activation fragment C3b, inhibiting all three complement pathways (classical, lectin, alternative) at the central C3 convertase level. Prevents formation of C3a (anaphylatoxin), C3b (opsonization), and downstream terminal complement activation. Broader inhibition than C5 blockers, which only prevent MAC formation.

Everyday: Blocks complement protein C3, which is the central hub of the immune system's "alarm cascade." While C5 inhibitors (like Soliris) block the alarm late, this drug blocks it at the crossroads — upstream of C5. Like shutting off the main water valve instead of just one faucet. This matters because some diseases are driven by C3 activation that C5 drugs can't reach.

Targets: []

Primary EP: [{"id":"peg-ep1","name":"Adjusted mean hemoglobin change at Week 16","type":"PRIMARY","unit":"g/dL","notes":"Difference: 3.84 g/dL favoring pegcetacoplan. Hb at Week 16: 11.54 vs ~7.2 g/dL.","p_value"

Safety: Injection site reactions 37% (vs 3% eculizumab; mostly mild, none led to discontinuation). Infections 29% vs 26%. No meningococcal infections in either group. Breakthrough hemolysis 10% controlled per

Primary EP: [{"id":"val-ep1","name":"Proteinuria reduction (UPCR) at Week 26","type":"PRIMARY","unit":"%","p_value":"<0.0001","results":[{"ci":"-74.9 to -57.2","arm":"val-pcc","label":"-67.2% reduction","value":-

Safety: Pegcetacoplan not associated with more AEs than placebo. No serious infections from encapsulated bacteria. 52-week extension showed durable proteinuria reduction maintained (-67.2% at 52 weeks).

C3 complement inhibitor for PNH and C3G. Originally developed by Apellis Pharmaceuticals. SOBI has ex-US rights. In PNH: shown superior to eculizumab (C5 inhibitor) in PEGASUS trial — upstream C3 blockade addresses extravascular hemolysis that C5 inhibitors miss. In C3G/IC-MPGN: EU approved (first treatment for this ultra-rare kidney disease). Japan registration ongoing. Competitive landscape: C5 inhibitors (Soliris, Ultomiris from AZN), Factor B inhibitors (iptacopan from NVS), Factor D inhibitors (danicopan from AZN/Alexion).