4′‐Demethyl‐epipodophyllotoxin‐β‐D‐thenylidene‐glucoside (PTG) in the treatment of malignant intracranial neoplasms

Twenty evaluable patients, 19 with primary intracranial neoplasms, were treated with intravenous PTG at weekly doses of 100 mg/m² to 130 mg/m² in a Phase II study. A total of 63 courses (6–8 doses/course) was administered. Antineoplastic activity was demonstrated by objective neurologic improvement in 5 of 13 patients with progressive neurologic findings at the outset of therapy. Of the remaining 7 asymptomatic patients, there has been a median progression‐free interval of 15+ months, with 5 patients remaining on study. Anemia and mild leukopenia, the most frequent toxicities, were clinically insignificant in 12 previously untreated patients. Among 8 patients with extensive prior chemotherapy, pancytopenia required discontinuation of therapy in 1 and decreased frequency of administration in 2 others. PTG is presented as an effective drug, with minimal toxicity, for the treatment of intracranial neoplasms. It would appear to offer potential as an agent for Phase III trials as well as a mode of therapy for those patients no longer able to tolerate nitrosoureas, or with disease progression on nitrosoureas.