PCNU: a new nitrosourea in clinical oncology

PCNU is a new nitrosourea compound which has recently entered clinical trials. Preclinically it has been found to be effective against a variety of tumor models. Biochemically, PCNU was found to have optimal lipophilic, alkylating, and carbamoylating properties as compared to other nitrosourea agents. PCNU is able to diffuse into the CSF as demonstrated by pharmacokinetic studies. Clinical phase I studies indicate that the main toxicity is myelosuppression; nausea and vomiting were less frequently observed with PCNU than with other nitrosourea compounds. Human antitumor activity has been reported in a number of tumors, but most consistently in brain tumors. Phase II studies are now underway to confirm the antitumor activity of PCNU.