The present disclosure relates to polypeptide modulators of complement activity, including cyclic polypeptide modulators. Included are methods of utilizing such modulators as therapeutics. Also provided are methods of measuring C5 and related complexes using C5 binding agents.本揭示內容係關於補體活性之多胜肽調節劑,包括環狀多胜肽調節劑。包含利用此等調節劑作為療法的方法。亦提供使用C5結合劑測量C5及相關複合物之方法。