APL-3001

APL-3001 is an investigational complement C3 inhibitor described in the provided context as a Phase 3 candidate for the treatment of pulmonary arterial hypertension (PAH). Developed as part of a complement-targeting platform (originally by Apellis Pharmaceuticals and subsequently acquired by Biogen), the drug is designed to inhibit the C3 protein, thereby preventing the downstream activation of the complement cascade. This mechanism is intended to address the inflammatory and fibroproliferative processes that drive vascular resistance in PAH. Note: In real-world clinical research, APL-3001 is the protocol identifier for the VALIANT Phase 3 trial of pegcetacoplan in C3 glomerulopathy, rather than a distinct drug candidate for PAH.