Agonist agents of CD47 inducing programmed cell death and their use in the treatments of diseases associated with defects in programmed cell death

An isolated cyclic peptide of general formula (Ia):

• or a pharmacologically acceptable salt thereof, wherein:
• Z1 is nothing or an heterochiral sequence D-Pro-L-Pro or any sequence of two amino acids or analogs of amino acid able to mimic said heterochiral sequence or mimic a beta turn;
• B2 represents the peptidic sequence X1-X2-X3-X4-X5-X6-X7-X8-X9-X10 (SEQ ID NO:
• 2) and comprises between 6 and 10 amino acids, wherein:
• X1 refers to nothing or serine;
• X2 refers to nothing, arginine, or N-methyl arginine;
• X3 refers to phenylalanine;
• X4 refers to tyrosine;
• X5 refers to valine;
• X6 refers to valine;
• X7 refers to methionine, lysine, or norleucine;
• X8 refers to tryptophan;
• X9 refers to nothing or lysine;
• X10 refers to nothing or glutamine;
• Z2 is nothing or an heterochiral sequence D-Pro-L-Pro or any sequence of two amino acids or analogs of amino acid able to mimic said heterochiral sequence or mimic a beta turn;
• B3 is a peptidic sequence of between 6 and 10 amino acids comprising the following sequence:
• -X19-X14-X15-X20-X21-X16-X22-X23-X17-X18- (SEQ ID NO:
• 36) wherein:
• X14 is nothing, glycine, alanine, or serine;
• X15 is isoleucine or leucine;
• X16 is lysine or alanine;
• X17 is nothing, asparagine, alanine, glutamine or lysine;
• X18 is nothing, serine, or glycine;
• X19 is nothing or serine;
• X20 is serine, alanine or leucine;
• X21 is valine or alanine;
• X22 is valine;
• and
• X23 is valine or alanine;
• wherein said isolated cyclic peptide comprises an even number of amino acids and wherein said isolated cyclic peptide comprises between 8 and 26 amino acids.