Compounds and methods for suppressing an immune response to substances containing polyethylene glycol

A compound, having the formula:

• or a pharmacologically acceptable salt thereof;
• wherein:
• A is a linking group having the formula —NHCO—, —CONH—, —NH—, —CO—, —O—, —COO—, —C(O)(CH2)3C(O)N(H)—, —OCH2C(O)NH(CH2)pNH— where p is 2-8, —OOC—, —S—, —SH—, —NCH2—, —CH2N—, ═N—, —N═, or
• B is an end group having the formula-OH, —OCH3, —OCH2CH3, —OCH2CH2CH3, —CH3, —C2H5, —C3H7, —C4H9, —C5H11, —COOH, —COO, —COOCH3, —COOCH2CH3, —COOC(CH3)3, —NH(CO)CH2NH(CO)OC(CH3)3, —NH(CO)OC(CH3)3, —NH(CO)CH2NH2, COOC(CH3)3, COOC(CH3)3, —N3, —NH2, or —NH3+;
• m is 0 to 100;
• x is 0 or 1;
• y is 0 to 20;
• n is 4 to 50;
• o is 2 to 200;
• and
• wherein the dextran has a molecular weight (MW) of about 40 kDa, in which >95% is within the range of 35-45 kDa.