Penclomedine, a synthetic pyridine derivative that has made its way to clinical trials because of the antitumor activity seen using the NCI screening program. Its mechanism of action is unknown although exists assumption that it can be metabolized to a free radical, DNA-reactive species. Penclomedine was involved in phase I clinical trial in treating patients with solid tumors or lymphoma. In this trial oral penclomedine was conducted to potentially alter the toxicity profile and to avoid the neurological side effects seen with i.v. penclomedine. The more favorable toxicity profile of penclomedine was obtained. It would seem reasonable to pursue a Phase II evaluation of p.o. penclomedine in patients with intracranial neoplasms, because central nervous system penetration appears unusually good. However, information about the further development of this drug is not available.