Cycloplatam and oxoplatin--the new antitumor platinum compounds of the second generation.

Cycloplatam, ammine(cyclopentylamino)-S-(-)-malatoplatinum(II), and oxoplatin, cis-dichloro-diammine-trans-dihydroxoplatinum(IV), were first synthesized in the USSR. Their antitumor properties were found at the All-Union Cancer Research Center of the Academy of Medical Sciences of the USSR by the authors of this article. Both new drugs are less toxic than cisplatin and free from nephrotoxicity. Both new compounds exceed cisplatin considerably in their action on plasmacytoma MOPC-406 and in complete cure of mice. Cycloplatam and oxoplatin have no cross-resistance with cisplatin and with the alkylating agent sarcolysin. As to antitumor activity cycloplatam exceeds carboplatin, (cyclobutane-I,I-dicarboxylato)-diammineplatinum(II), oxoplatin--iproplatin, cis-dichloro-bis (isopropylamine)-trans-dihydroxoplatinum(IV). Both drugs have been handed over for preclinical study.