Phase II Study of Cisplatin and Oral VP16 in Patients with Refractory or Relapsed Ewing Sarcoma

Background: Phase II trials demonstrate the activity of cisplatin in patients with refractory Ewing sarcoma family tumours (ESFT) and also the feasibility of giving cisplatin with oral VP16 in a variety of different cancers. This trial was conducted to evaluate the activity and toxicity profile of this combination delivered as outpatient therapy in patients with refractory/relapsed ESFT.

Methods: Cisplatin was administered on days 1, 8 and 15 and days 29, 36 and 43 (70 mg/m(2)/dose for patients <21 years of age and 50 mg/m(2)/dose ≥21 years). VP16 was administered at a dose of 50 mg/m(2) on days 1-15 and days 29-43 inclusive. A three-stage Fleming statistical design was used for analysis.

Results: Between January 2003 and October 2006, 45 patients aged between 5 and 46 years (median 19) were enrolled. Thirty-eight were evaluable for response. Patients had previously received one to three lines of chemotherapy (median = one). Seventy-three per cent of the patients had grade 3/4 neutropenia, 20 % developed fever, 40 % had grade 3/4 anaemia, 68 % grade 3/4 thrombocytopenia and 16 % grade 2/3 ototoxicity. Measured response after 2 cycles: 0 CR, 7 PR (18 %), 13 SD (34 %), 18 PD (48 %). There was excellent concordance between unidimensional and bidimensional criteria in 31 of 33 responses (94 %). PFS at 1 year was 39 %, with a median PFS of 6 months. Overall survival at 1 year was 44 %; median survival was 11 months.

Conclusions: Cisplatin combined with oral VP16 is well tolerated and has acceptable side effects, but limited clinical activity in refractory/relapsed ESFT.