Respiratory syncytial virus (RSV) replication inhibitors

A polypeptide that interacts or interferes with the binding of the RSV nucleoprotein N with the RSV phosphoprotein P by disrupting, impairing and/or displacing the N0-P interaction, wherein said polypeptide is internally cross-linked and is selected from:

• an amino acid sequence:
• A11 A12 A13 A14 A15 A16 A17 A18 A19 A20 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 (SEQ ID NO:
• 2);
• or
• an amino acid sequence:
• A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20 A21 A22 A23 A24 A25 A26 A27 A28 A29 A30 (SEQ ID NO:
• 3);
• or a fragment thereof, wherein the fragment contains at least 15 contiguous amino acids of SEQ ID NO:
• 3;
• or a pharmaceutically acceptable salt thereof;
• and wherein said polypeptide includes at least two modified amino acids that together form an internal cross-link wherein said internally cross-linked amino acids are located at positions selected from A15, A16, A18, A19, A22, A23, A26, A27, A29, and A30 and are separated by 2 (i, i+3), 3 (i, i+4) or 6 (i, i+7) amino acids, and wherein those modified amino acids are selected from R,S-bis-pentenyl-glycine, S-pentenyl-alanine, R-pentenyl-alanine, S-octenyl-alanine and R-octenyl-alanine and wherein:
• A7 is Glu, or any other polar negatively charged amino acid,
• A8 is Phe or Trp, or any other large aromatic amino acid,
• A9 is His,
• A10 is Gly or Ala,
• A11 is Glu or Asn,
• A12 is Asp or Gin,
• A13 is Ala, Gly, Val, Leu, Ile, Phe, Met or Trp,
• A14 is Asn or Gln,
• A15 is Asn or Gln,
• A16 is Lys or Arg,
• A17 is Ala, Gly, Val, Leu, Ile, Phe, Met or Trp or any other nonpolar amino acid,
• A18 is Thr, Val, Ile or Leu,
• A19 is Lys or Arg,
• A20 is Phe or Trp, or any other large aromatic amino acid,
• A21 is Leu, Gly, Val, Ile, Phe, Met or Trp or any other nonpolar amino acid,
• A22 is Glu or Asp,
• A23 is Ser, Ala, Thr or Gly,
• A24 is Ile, Gly, Val, Leu, Phe, Met or Tip or any other nonpolar amino acid,
• A25 is Lys or Arg,
• A26 is Gly, Ala, Val, Leu or Ile,
• A27 is Lys or Arg,
• A28 is Phe, Tyr or Tip, or any other nonpolar amino acid,
• A29 is Ala, Gly, Val, Leu, Ile, Phe, Met or Tip,
• A30 is Ser.