Cycloplatam, a new platinum derivative, evolved at N.S. Kurnakov Institute of General and Inorganic Chemistry in 1982, has been added to the arsenal of Russian cytostatic drugs. Having passed phase I trials, it was approved for treatment of pleural mesothelioma, ovarian carcinoma and multiple myeloma. Leukothrombocytopenia formation indicates toxicity-related limit of dosage. Phase II clinical trials are under way at the Center. They include treatment of solid tumors with cycloplatam alone in urinary bladder tumors, cervical carcinoma and malignant pleurites of various etiology as well as in combination with other cytostatics (carcinoma of the prostate, pleural mesothelioma and urinary bladder tumors). The drug may be recommended both for oral and intracavitary administration; side-effects may include moderate toxicity, chiefly, hematological one.