Combination of gemcitabine and docetaxel: a regimen overestimated in refractory metastatic osteosarcoma?

BACKGROUND: The combination of gemcitabine and docetaxel (GT) has been demonstrated to be effective against various types of solid tumors, including sarcoma. However, the regimen has not been confirmed in large, well-designed clinical trials in refractory metastatic osteosarcoma. METHODS: We retrospectively reviewed the records of patients with refractory metastatic osteosarcoma at Peking University People’s Hospital who were treated with gemcitabine (1000 mg/m(2)) intravenously (IV) on Day 1 and Day 8, and docetaxel (75 mg/m(2)) IV on Day 8, repeated every 21 days. RESULTS: A total of 52 patients with a median age of 18.4 years were treated with GT at the Peking University People’s Hospital from August 2012 to August 2017. A total of 174 courses were administered. Only five patients with pulmonary metastasis achieved a best response of stable disease (SD), while all other patients had progressive disease. The result was disappointing with an ORR of 0%, a DCR of 9.6%, and a median DOR of 3.5 months. Grade 3 or 4 toxicities were observed in 69 (39.7%) courses and in 28 (53.8%) patients, most of which were myelosuppression, especially thrombocytopenia. No fatal adverse effect (AE) was found. CONCLUSION: The combination of gemcitabine and docetaxel (GT) as a salvage regimen is well-tolerated but not as effective as expected in refractory metastatic osteosarcoma. This report highlights the need for the development of new approaches with higher activity in these patients.