Novel-fosfamide monotherapy or in combination with doxorubicin versus doxorubicin alone in patients with advanced soft tissue sarcoma: A pooled analysis of randomized clinical trials

BACKGROUND: Novel-fosfamides (NFOs) belong to active metabolites of ifosfamide that bypass the generation of toxic byproducts. In this analysis, we aimed to comprehensively assess the benefits and risks of NFO monotherapy or in combination with doxorubicin (DOX) versus single-drug DOX in previously untreated patients with advanced soft-tissue sarcoma (ASTS). METHODS: Online PubMed, Web of Science, Embase, and Cochrane CENTRAL databases were systematically searched on April 26, 2022. Objective response rate and disease control rate were primary outcomes. Overall survival (OS), progression-free survival (PFS), and grade ≥ 3 treatment-related adverse events were secondary outcomes. RESULTS: In all, 3 randomized clinical trials with a total of 1207 ASTS patients were eligible. DOX plus NFO combination therapy showed higher risk ratios of objective response rate (1.50, 95% CI 1.20–1.68, P = .0003) and disease control rate (1.15, 95% CI 1.05–1.27, P = .0030) compared with DOX monotherapy. Nevertheless, NFO-based monotherapy and combination therapy were found no improvements on OS (hazard ratio 0.93, 95% CI 0.52–1.65, P = .8050) and PFS (hazard ratio 0.88, 95% CI 0.54–1.43, P = .6088) against DOX. More incidences of grade 3 or worse anemia, thrombocytopenia, stomatitis, diarrhea, constipation, and febrile neutropenia were observed in NFO-based treatments. CONCLUSION: Adding NFO to DOX as first-line therapy improved the responses in ASTS patients but did not prolong OS and PFS. Grade 3 or worse treatment-related adverse events should be treated with caution during the NFO-based therapies.