A multicentric randomized phase II clinical trial evaluating high-dose thiotepa as adjuvant treatment to standard chemotherapy in patients with resectable relapsed osteosarcoma

• Published in: European journal of cancer (1990) 2020-01, Vol.125, p.58-68
• Main Authors: Marec-Berard, Perrine, Dalban, Cécile, Gaspar, Nathalie, Brugieres, Laurence, Gentet, Jean-Claude, Lervat, Cyril, Corradini, Nadège, Castex, Marie-Pierre, Schmitt, Claudine, Pacquement, Hélène, Tabone, Marie-Dominique, Brahmi, Mehdi, Metzger, Séverine, Blay, Jean-Yves, Pérol, David
• Format: Article
• Language: English
• Subjects: Adjuvant therapy; Autografts; Biomedical materials; Bone cancer; Chemotherapy; High-dose chemotherapy; Immunological tolerance; Males; Metastases; Osteogenic sarcoma; Osteosarcoma; Patients; Randomization; Relapse; Sarcoma; Surgery; Survival; Thiotepa; Toxicity; Transplantation
• ISSN: 0959-8049; 1879-0852
• DOI: 10.1016/j.ejca.2019.11.007

The role of high-dose chemotherapy in relapsing osteosarcomas has not been established. We evaluated the efficacy and tolerance of high-dose thiotepa (HDTp) after standard chemotherapy (SCT) in patients with relapsed osteosarcoma. This randomised open-label phase II study enrolled patients 1–50 years, with local or metastatic relapse of a high-grade osteosarcoma, not progressive after two cycles of SCT, for whom a complete surgery can be achievable following treatment. The trial assigned enrolled patients in a 1:1 ratio to receive two additional courses of SCT + HDTp and autologous transplantation (Arm A), or SCT alone (Arm B). Surgery for complete resection was scheduled as soon as feasible. Primary endpoint was overall survival (OS). Secondary objectives included progression-free survival (PFS) and safety. From September 2009 to November 2016, 44 patients were randomised (A:22; B:22). In total, 54.5% were males, and the median age was 16 years (9-32years). The two-year OS rate was 66.7% (95% CI 42.5–82.5) (SCT + HDTp, Arm A) versus 50.0% (95% CI 28.2–68.4) for SCT alone (Arm B). Median OS was 27.4 and 24.8 months, respectively (hazard ratio [HR] 0.826, 95% CI 0.393–1.734; p = 0.6123). Median PFS was 15.6 (8.9–24.9) months in Arm A versus 7.2 (4.8–33.3) months in Arm B, p = 0.3845. Among the 22 patients treated with SCT + HDTp, 16 (72.7%) experienced at least one grade ≥3 adverse events versus 18/22 (81.8%) patients treated with SCT. No toxic death occurred. Adjuvant HDTp failed to significantly improve OS and PFS in resectable relapsed osteosarcomas. Despite a trend of prolonged survival and an acceptable toxicity, thiotepa cannot be recommended. HDTp and autologous transplantation added to SCT did not improve OS and PFS in patients with resectable relapsed osteosarcomas. Despite a trend of prolonged survival, thiotepa cannot be recommended. •NCT 00978471 is a randomised phase II study of 44 patients with relapsed osteosarcoma.•Arm A: chemotherapy + thiotepa and autologous transplantation; Arm B: chemotherapy.•Added high-dose thiotepa and autologous transplantation did not improve OS and PFS.•Experienced ≥1 Grade ≥ 3 adverse event: Arm A (72.7%) versus Arm B 81.8%.•Despite acceptable toxicity, thiotepa is not recommended out of clinical trial.