Apatinib plus ifosfamide and etoposide versus ifosfamide and etoposide in patients with advanced osteosarcomas (OAIE/PKUPH-sarcoma 11): a randomized phase II study

Relapsed or refractory osteosarcoma carries a poor prognosis after standard chemotherapy. We conducted a multicenter, randomized, phase II trial (NCT05277480) to compare apatinib plus ifosfamide/etoposide (IE) with IE alone in patients who had progressed following at least one prior line of chemotherapy. Patients were randomized 2:1 to receive apatinib (500 mg orally once daily) plus IE (ifosfamide 1.8 g/m²/day and etoposide 100 mg/m²/day, days 1-3 every 3 weeks) or IE alone (same doses, days 1-5 every 3 weeks). The primary endpoint was progression-free survival (PFS). Between April 14, 2022, and August 22, 2023, 81 patients were enrolled (53 in apatinib plus IE group and 28 in IE group). After a median follow-up of 19.9 months, the median PFS was 5.5 months (95% confidence interval [CI]: 3.9, 6.4) with apatinib plus IE compared with 3.4 months (95% CI: 1.4, 4.6) with IE (hazard ratio, 0.60; 95% CI: 0.37, 0.98; P = 0.0402). The trial met its pre-specified primary endpoint. These results suggest that apatinib plus IE may improve PFS in relapsed or refractory osteosarcoma, but as a randomized phase II study, the findings are exploratory and require confirmation in phase III trials.