FIELD: chemistry of peptides, medicine. SUBSTANCE: invention relates to peptides of the formula (I): X-A1-A2-Trp-Ala-Val-Gly-His-Leu-psi-A9-Q where X means hydrogen, simple bond binding alpha-amino-group of A1 with gamma-carboxyl moiety at 3-propionyl part of A2 if A2 is Glu[-], or group of the formula R1CO- where R1 is taken from the group involving: hydrogen, C1-10-alkyl or phenyl-C1-10-alkyl; A1 means D- or L-amino acid residue taken from the group involving: Phe, p-HI-Phe, pGlu, NaI, PaI, Tri, unsubstituted Trp or Trp substituted at benzene ring with one or some substituents from the group involving C1-3-alkyl; or A1 means peptide bond binding acyl moiety of R1-CO with alpha-amino-moiety of A2 if A2 means Gln, Glu[-]Glu (Y) or His where [-] means simple bond binding gamma-carboxyl group of A2 with alpha-amino-group of A1 if A2 means Glu where X means simple bond, Y means OR5 where R5 is hydrogen, C1-3-alkyl or phenyl; Leu-psi means reduced form of Leu where C= O-moiety presents instead CH2 so that a bond of indicated CH2-moiety with alpha-amino-group of adjacent A9-residue is a pseudopeptide bond; A9 means Tac, MTac or DMTac; Q means NH2 or CQI where QI is hydrogen, and to pharmaceutically acceptable acids or salts and pharmaceutical composition showing antagonistic activity with respect to bombesine and to method of treatment of mammalian with cancer based on peptides of the formula (I). EFFECT: improved method of synthesis, enhanced effectiveness of treatment. 15 cl, 15 ex, 6 tbl, 4 dwg
