From August 18th 2026, GtoPdb will require users to register to use the website. Please see our blog post for more information.

complement C5   Click here for help

GtoPdb Ligand ID: 8712

Immunopharmacology Ligand
Compound class: Endogenous peptide in human, mouse or rat
Comment: This is the full length, pre-pro-protein structure as represented in NCBI Reference Sequence: NP_001726. This peptide is cleaved into the complement C5 beta chain, complement C5 alpha chain and C5a anaphylatoxin (see the UniProt entry for the human protein P01031).

C5 inhibition is a clinically validated mechanism that is utilised for the control and suppression of complement-induced hemolysis in patients with paroxysmal nocturnal hemoglobinuria (PNH). Eculizumab is a clinically approved anti-C5 monoclonal antibody for PNH. Investigational Phase 1/2 anti-C5 monoclonal RG6101 (SKY59 [4]; IMGT 783) was granted FDA orphan drug designation in September 2017 for the treatment of paroxysmal nocturnal hemoglobinuria (PNH). Ra Pharmaceuticals is developing a C5 binding synthetic 15-amino-acid macrocyclic peptide (designated research code RA101495; Phase 2) for PNH and other complement-mediated illnesses. RA101495 was granted FDA orphan drug designation for PNH in July 2017. RA101495 binds to a site on C5 distinct from the eculizumab binding site, with the aim of overcoming eculizumab resistance, such as that observed in patients with the Arg885His C5 variant [6] (note that RA101495 is also effective against this variant [4]). It is also designed for subcutaneous self-administration, which would be more convenient for patients, who must be given eculizumab by i.v. infusion by a healthcare professional.

SARS-CoV-2 and COVID-19: Clinically approved and investigation candidates that target C5 are being evaluated in a number of clinical trials to determine their potential to combat complement-mediated inflammatory tissue damage in the organs of pateints with severe COVID-19.
Species: Human
Classification Click here for help
Compound class Endogenous peptide in human, mouse or rat
Ligand families/groups Complement components and ligands
Gene/Precursor Click here for help
Gene symbol Gene name Species Precursor protein name Synonyms
C5 complement C5 Human prepro-C5 complement component 5, CPAMD4
Database Links Click here for help
Ensembl Gene ENSG00000106804 (Hs)
Entrez Gene 727 (Hs)
GtoPdb PubChem SID 252827370
Human Protein Atlas ENSG00000106804 (Hs)
UniProtKB P01031 (Hs)