High-dose VP-16-213 monotherapy for refractory germinal malignancies: a phase II study.

VP-16-213 at standard dose is one of the more active agents for the treatment of germ cell tumors. In previous phase I studies, VP-16-213 has been investigated in suprastandard dose when hematopoietic reconstitution was assured by autologous bone marrow transplantation (ABMT). This phase II study was performed to explore the possibility that an augmented dose of VP-16-213 may be more active than standard dose against germ cell tumors. Eleven patients with progressive refractory germ cell tumors were treated with high-dose VP-16-213: 2,400 mg/m2 with ABMT every three to four weeks followed by 1,200 mg/m2 without ABMT. Seven patients had received VP-16-213 at standard dose prior to high-dose VP-16-213. Toxicity to high-dose VP-16-213 included severe myelosuppression, nausea, vomiting, alopecia, mucositis, and hepatitis. Of 10 evaluable patients, two complete responses and four partial responses, all of short duration, were obtained. However, some patients unresponsive to standard-dose VP-16-213 exhibited responses to the augmented-dose VP-16-213. Therefore, although more myelosuppressive, VP-16-213 may have increased activity against germ cell tumors when administered at augmented dose. High-dose VP-16-213 may be considered in designing new approaches for initial management of patients with germ cell tumors not expected to be cured with standard chemotherapy.