A Phase II Study of Docetaxel in Patients with Relapsed and Refractory Ewing's Tumours

Comprehensive analysis of published phase I/II clinical trials between 1990-2010 in osteosarcoma and Ewing sarcoma confirms limited outcomes and need for translational investment

Background

High grade primary bone sarcomas are rare cancers that affect mostly children and young adults. Osteosarcoma and Ewing sarcoma are the most common histological subtypes in this age group, with current multimodality treatment strategies achieving 55-70% overall survival. As there remains an urgent need to develop new therapeutic interventions, we have reviewed published phase I/II trials that have been reported for osteosarcoma and Ewing sarcoma in the last twenty years.

Results

We conducted a literature search for clinical trials between 1990 and 2010, either for trials enrolling bone sarcoma patients as part of a general sarcoma indication or trials specifically in osteosarcoma and Ewing sarcoma. We identified 42 clinical trials that fulfilled our search criteria for general sarcoma that enrolled these patient groups, and eight and twenty specific trials for Ewing and osteosarcoma patients, respectively. For the phase I trials which enrolled different tumour types our results were incomplete, because the sarcoma patients were not mentioned in the PubMed abstract. A total of 3,736 sarcoma patients were included in these trials over this period, 1,114 for osteosarcoma and 1,263 for Ewing sarcoma. As a proportion of the worldwide disease burden over this period, these numbers reflect a very small percentage of the potential patient recruitment, approximately 0.6% for Ewing sarcoma and 0.2% for osteosarcoma. However, these data show an increase in recent activity overall and suggest there is still much room for improvement in the current trial development structures.

Conclusion

Lack of resources and commercial investment will inevitably limit opportunity to develop sufficiently rapid improvements in clinical outcomes. International collaboration exists in many well founded co-operative groups for phase III trials, but progress may be more effective if there were also more investment of molecular and translational research into disease focused phase I/II clinical trials. Examples of new models for early translational and early phase trial collaboration include the European based EuroBoNeT network, the Sarcoma Alliance for Research through Collaboration network (SARC) and the new European collaborative translational trial network, EuroSarc.

A Phase II Study of Docetaxel for the Treatment of Recurrent Osteosarcoma

Purpose: To determine the response and toxicity of docetaxel in recurrent osteosarcoma and related spindle cell tumours of bone.

Patients and methods: Fourteen patients, 10 males and four females, were enrolled, median age 30.5 years (range, 17–46). Diagnosis was: conventional osteosarcoma, 12 patients; periosteal osteosarcoma, one patient; and malignant fibrous histiocytoma of bone, one patient. Initial chemotherapy had been with doxorubicin and cisplatin in 10 patients, and multiagent regimens in four. Nine had been treated with second line chemotherapy before receiving docetaxel. Thirteen patients had lung metastases and one intra-abdominal disease. Docetaxel 100 mg/mα² was given as a 1-h infusion every 3 weeks. Response was assessed every two cycles to a maximum of six.

Results: A total of 43 cycles were given, median of two per patient (range 1–6). Thirteen patients were evaluable for response. A single partial remission was seen, for a response rate of 8%. Two patients had stable disease, and one patient a mixed response. Forty cycles were evaluable for toxicity. The principle toxicity was haematological, with a median neutrophil count of 0.9 (range 0–9.6). There were four episodes of neutropenic sepsis (10%). The only non-haematological toxicity ≥grade 3 was stomatitis, occurring in just one patient. There were no toxic deaths.

Conclusion: Docetaxel at this dose and schedule is well tolerated, but is not associated with significant activity in patients with relapsed osteosarcoma.