Brequinar sodium (DUP 785, NSC 368390) is a novel quinoline-carboxylic acid derivative that has been selected for clinical evaluation because of its broad spectrum of antitumor activity in animal models and its novel chemical structure. This compound inhibits the mitochondrial enzyme dihydroorotate dehydrogenase (DHO-DH), which catalyzes the conversion of dihydroorotate to orotate, leading to a blockage in the pyrimidine de novo biosynthesis. A total of 43 patients received 110 courses of Brequinar sodium by short-term intravenous (i.v.) infusion, which was repeated every 3 weeks. Dose escalation was initially based on a modified Fibonacci scheme. After pharmacokinetic data from mice and man became available, a pharmacologically guided dose escalation was used; at toxic levels, dose escalation was applied on the basis of clinical judgement. The dose-limiting toxicities were myelosuppression, mucositis, skin rash, nausea and vomiting. The maximum tolerable doses for poor- and good-risk patients were 1,500 and 2,250 mg/m2, respectively. One mixed response was observed in a patient with papillary carcinoma of the thyroid. The recommended doses for phase II studies are 1,200 and 1,800 mg/m2 Brequinar sodium, given by a 1-h i.v. infusion every 3 weeks to poor- and good-risk patients, respectively.
Twenty-six adult patients were entered in a phase I trial of carboplatin, a new cisplatin derivative with reduced potential for nephrotoxicity. All patients had solid tumors and the median World Health Organization performance score was 2 (0-3). Twelve patients had not received prior chemotherapy. The drug was administered as a 15-minute IV infusion, without pre- or posthydration, at daily doses of 40-125 mg/m2 for five consecutive days. Antiemetics were given only if needed. Thrombocytopenia and neutropenia were dose related and dose limiting. One patient died from septic shock at the highest dose level. Nonhemolytic anemia was also encountered. Nausea and vomiting were experienced by most patients but gastrointestinal intolerance was severe in only two patients. One patient had hypercreatininemia, which was minor and rapidly reversible. Other toxic effects consisted of negligible fatigue, paresthesia, pruritus, local pain, stomatitis, headache, and alopecia. Although none of the patients achieved a partial or complete response, antitumor effect was strongly suggested in two patients with thyroid and cervix cancer, respectively. Carboplatin is an attractive candidate for phase II trials. In good-risk patients, such trials could be initiated at a daily dose of 100 mg/m2 for five consecutive days every five to six weeks.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.