A compound comprising a modified compstatin peptide (ICVVQDWGHHRCT (C2-C12 cyclic； SEQ ID NO: 1), wherein the modification comprises an additional or substituted N-terminal component that improves (1) the binding affinity of C3, C3b o C3c of the peptide, (2) the solubility of the peptide in aqueous liquids, and / or (3) the plasma stability of the peptide and / or residence time in the plasma, compared to an unmodified compstatin peptide under equivalent conditions, where the additional component is D-Tyr, D-Phe, Tyr (Me), D-Trp, D-Cha, Phe, N-methyl Gly (Sar), Arg, mPhe, mVal, or Tyr, and where the N-terminal substituted component comprising Ile at position 1 is replaced by Ac-Trp； wherein the compound further comprises one or more of: (1) replacement of His at position 9 by Ala； (2) replacement of Val at position 4 for Trp or a Trp analog, wherein the Trp analog is optionally 1-methyl Trp or 1-formyl Trp； (3) replacement of Trp at position 7 with an analog of Trp, where optionally the Trp analog is a halogenated Trp； (4) modification of Gly at position 8 to reduce structural conformation at this location, where optionally the structure is reduced by replacement of Gly at position 8 (Gly8) with N-alpha-methyl Gly； (5) replacement of Thr at position 13 by Ile, Leu, Nle, N-methyl Thr or N-methyl Ile； and (6) replacement of the disulfide bond between C2 and C12 with a thioether bond to form a cystathionine or a lanthithionine.Un compuesto que comprende un péptido de compstatina modificado (ICVVQDWGHHRCT (C2-C12 cíclico； SEQ ID NO:1), en donde la modificación comprende un componente N-terminal adicional o sustituido que mejora (1) la afinidad de unión de C3, C3b o C3c del péptido, (2) la solubilidad del péptido en líquidos acuosos, y/o (3) la estabilidad plasmática del péptido y/o tiempo de permanencia en el plasma, en comparación con un péptido de compstatina sin modificar bajo condiciones equivalentes, en donde el componente adicional es D-Tyr, D-Phe, Tyr(Me), D-Trp,
