Abstract: According to the present invention, there is a demand for novel platinum(IV) complex which has sufficient water-solubility, stability, antitumor activity, and the like that are required as a medicine, and may be used clinically. Thus, provided is a platinum(IV) complex represented by the following General Formula (I) [wherein X1 and X2 each represent a halogen atom or are bonded together to form a dicarboxylate selected from the group consisting of oxalate, malonate, succinate, and o-phthalate; and Y represents a halogen atom.

Abstract: A DDS preparation of a platinum complex, which exhibits a superior antitumor effect required as a medicine and reduced side effects, that is, a clinically usable DDS preparation of a platinum complex, which is conjugated to a polymer carrier that is different from conventional carriers, is desired. Provided is a polymer conjugate of a platinum(II) complex, the polymer conjugate including: a block copolymer having a polyethylene glycol structural moiety and a polyaspartic acid moiety or a polyglutamic acid moiety; a sulfoxide derivative introduced into a side-chain carboxyl group of the block copolymer; and a platinum(II) complex coordinate-bonded to a sulfoxide group of the sulfoxide derivative.

Abstract: A physiologically active substance-conjugated block copolymer having enhanced efficacy and/or safety is provided by enhancing the property of penetrating into a target diseased tissue and/or enhancing excretability, compared to known physiologically active substance-conjugated block copolymer, and suppressing sensitization of the physiologically active substance to normal tissues other than a target diseased tissue. Disclosed is a block copolymer including a polyethylene glycol segment connected with a polyamino acid derivative segment conjugated with a physiologically active substance, in which the molecular weight of the block copolymer is from 2 kilodaltons to 15 kilodaltons, and the light scattering intensity of a 1 mg/mL aqueous solution of the physiologically active substance-conjugated block copolymer as measured with a laser light scattering photometer is at least twice or more the light scattering intensity of toluene.

Abstract: A DDS preparation of a platinum complex, which exhibits a superior antitumor effect required as a medicine and reduced side effects, that is, a clinically usable DDS preparation of a platinum complex, which is conjugated to a polymer carrier that is different from conventional carriers, is desired. Provided is a polymer conjugate of a platinum(II) complex, the polymer conjugate including: a block copolymer having a polyethylene glycol structural moiety and a polyaspartic acid moiety or a polyglutamic acid moiety; a sulfoxide derivative introduced into a side-chain carboxyl group of the block copolymer; and a platinum(II) complex coordinate-bonded to a sulfoxide group of the sulfoxide derivative.

Abstract: According to the present invention, there is a demand for novel platinum(IV) complex which has sufficient water-solubility, stability, antitumor activity, and the like that are required as a medicine, and may be used clinically. Thus, provided is a platinum(IV) complex represented by the following General Formula (I) [wherein X1 and X2 each represent a halogen atom or are bonded together to form a dicarboxylate selected from the group consisting of oxalate, malonate, succinate, and o-phthalate; and Y represents a halogen atom.

Abstract: A physiologically active substance-conjugated block copolymer having enhanced efficacy and/or safety is provided by enhancing the property of penetrating into a target diseased tissue and/or enhancing excretability, compared to known physiologically active substance-conjugated block copolymer, and suppressing sensitization of the physiologically active substance to normal tissues other than a target diseased tissue. Disclosed is a block copolymer including a polyethylene glycol segment connected with a polyamino acid derivative segment conjugated with a physiologically active substance, in which the molecular weight of the block copolymer is from 2 kilodaltons to 15 kilodaltons, and the light scattering intensity of a 1 mg/mL aqueous solution of the physiologically active substance-conjugated block copolymer as measured with a laser light scattering photometer is at least twice or more the light scattering intensity of toluene.