Off-label use of targeted therapies in osteosarcomas: data from the French registry OUTC'S (Observatoire de l'Utilisation des Thérapies Ciblées dans les Sarcomes):

BACKGROUND: The objective of this study is to explore the off-label use of targeted therapies (TTs) for patients with osteosarcoma registered within the French Sarcoma Group--Bone Tumor Study Group (GSF-GETO) national registry. METHODS: All patients with an osteosarcoma, registered between January 1, 2009 and July 15, 2013 were analyzed. RESULTS: Twenty-nine patients with refractory relapsed osteosarcomas received 33 treatment lines of TTs. The median age at the beginning of treatment was 19 years (range 9-72). The median number of previous lines of chemotherapy was 3 (range 1-8). Before inclusion, 3 patients were in second complete remission, 26 were in progression for metastatic relapse. Twenty-three patients received sirolimus (in combination with cyclophosphamide for 18); 5, sunitinib; 4, sorafenib; and one, pazopanib. Stable disease was observed for 45.5% of patients (95% Confidence Interval (CI) [20-52.8]). The median Progression-Free Survival (PFS) was 3 months (95% CI [2-5.4]) for patients treated by sirolimus and 1.8 months (95% CI [1.3-2.8]) for patients receiving multi-targeted tyrosine kinase inhibitors; 6-month PFS 15%. The median Overall Survival (OS) was 6.8 months (95% CI [4.7-12.1]), and one-year OS was 24%. In a multivariate analysis, PFS was superior for patients receiving sirolimus compared to other TTs (Hazard Ratio (HR) = 2.7, 95% CI [1.05-7.1]). No toxic death was reported. Grade 3 and 4 toxicities were observed in 27 and 6% of cases respectively. CONCLUSION: Off-label TTs, especially sirolimus, reported benefit in the treatment of refractory osteosarcomas with an acceptable toxicity profile, including in pediatric population

Late toxicity comparison of alkylating-based maintenance regimen with cyclophosphamide (VAC) vs ifosfamide (VAI) in Ewing sarcoma survivors treated in the randomized clinical trial Euro-EWING99-R1 in France

International audienceIn Euro-EWING99-R1 randomized trial, cyclophosphamide was shown to be noninferior to ifosfamide in the consolidation of standard-risk Ewing sarcoma (SR-EWS) after a common induction with VIDE (vincristine-ifosfamide-doxorubicin-etoposide). We present the results of the late effects analysis of VAC (vincristine-dactinomycin-cyclophoshamide) vs VAI (vincristine-dactinomycin-ifosfamide) conducted in Euro-EWING99-R1 French cohort. Of 267 French randomized patients, 204 were alive and free-of-relapse at 5-years including 172 with available long-term follow-up data concerning cardiac, renal and/or gonadal functions (sex-ratio M/F = 1.3, median age at diagnosis = 14 years): 84 randomized in VAC (median cumulative doses: cyclophosphamide = 9.7 g/m2, ifosfamide = 59.4 g/m2) and 88 in VAI (ifosfamide = 97.1 g/m2). With a median follow-up of 10 years (range = 5-17), five late relapses and five second malignancies were recorded. The 10-year event-free survival among 5-year free-of-relapse survivors was similar between VAC and VAI (93% vs 95%, P =.63). We estimated the 10-year cumulative probabilities of cardiac and kidney toxicities at 4.4% (95% confidence interval [95% CI] = 1.1%-7.6%) and 34.8% (95% CI = 26.8%-42.0%), respectively. Cardiac toxicity cumulative probability was similar in both arms, whereas kidney toxicity was higher in VAI (at 10 years, 43.0% vs 25.7%, P =.02), resulting from significant difference in glomerular toxicity (31.1% vs 13.1%, P <.01). At 10 years, gonadal toxicity was observed in 27% and 28% of pubertal men and women, respectively, without significant difference between VAC and VAI. Kidney and gonadal toxicities represent major issues in Euro-EWING99-R1, with significantly higher risk of kidney toxicities with VAI, without significant gonadal toxicity reduction. These results support the need to limit cumulative doses of both alkylating agents and to use mixed regimen as in VIDE-VAC or VDC/IE (vincristine-doxorubicin-cyclophoshamide/ifosfamide-etoposide)