A phase II study using a topoisomerase I-based approach in patients with multiply relapsed germ-cell tumours

The outcome of patients with germ-cell tumours (GCTs), who relapse more than once or relapse with a mediastinal primary is poor. We have shown that topoisomerase 1 may be an attractive target in relapsed GCT. We investigated the role of irinotecan, paclitaxel and oxaliplatin (IPO) followed by topotecan-based high-dose therapy in responding patients, in this patient population.

Twenty-eight patients with multiply relapsed gonadal and mediastinal GCT were recruited to this phase 2 study. All patients received IPO chemotherapy and 12 (43%) went on to receive high-dose therapy. The outcome of these patients was assessed using the Kaplan-Meier method with a median progression-free follow-up of 1 year.

Twenty patients (71%) responded to the therapy including five complete remissions (18%), 13 (46%) marker-negative partial responses and two (7%) marker-positive partial responses. Nine (32%) patients continue to be progression free, and the median survival for the whole group currently measures 17 months. Out of 12 individuals who received subsequent high-dose therapy consolidation, seven (58%) remain progression free. The commonest grade III/IV toxicity was infection (68%) and there were no IPO-related toxic deaths; there was one death from high-dose therapy.

Topoisomerase I-based IPO chemotherapy that lacks etoposide is very active in multiply relapsed GCT. This data merit further investigation.