Prospective, Multicenter Phase II Trial of Non-Pegylated Liposomal Doxorubicin Combined with Ifosfamide in First-Line Treatment of Advanced/Metastatic Soft Tissue Sarcomas

Simple Summary This clinical investigation reports the results of a prospective, multicenter phase II trial designed to evaluate the activity and safety of combining non-pegylated liposomal doxorubicin (NPLD) with ifosfamide as a first-line treatment for advanced/metastatic STS. The study results demonstrate a remarkable overall response rate (ORR) alongside a satisfactory disease control rate (DCR) while maintaining acceptable levels of toxicity. The addition of NPLD to ifosfamide, showing high activity and a low toxicity profile, makes this drug combination a useful option for patients with advanced/metastatic STS. These findings provide a promising basis for further comprehensive research into the clinical application of this drug combination in this disease setting.Abstract Doxorubicin is a widely used anticancer agent as a first-line treatment for various tumor types, including sarcomas. Its use is hampered by adverse events, among which is the risk of dose dependence. The potential cardiotoxicity, which increases with higher doses, poses a significant challenge to its safe and effective application. To try to overcome these undesired effects, encapsulation of doxorubicin in liposomes has been proposed. Caelyx and Myocet are different formulations of pegylated (PLD) and non-pegylated liposomal doxorubicin (NPLD), respectively. Both PLD and NPLD have shown similar activity compared with free drugs but with reduced cardiotoxicity. While the hand-foot syndrome exhibits a high occurrence among patients treated with PLD, its frequency is notably reduced in those receiving NPLD. In this prospective, multicenter, one-stage, single-arm phase II trial, we assessed the combination of NPLD and ifosfamide as first-line treatment for advanced/metastatic soft tissue sarcoma (STS). Patients received six cycles of NPLD (50 mg/m2) on day 1 along with ifosfamide (3000 mg/m2 on days 1, 2, and 3 with equidose MESNA) administered every 3 weeks. The overall response rate, yielding 40% (95% CI: 0.29-0.51), resulted in statistical significance; the disease control rate stood at 81% (95% CI: 0.73-0.90), while only 16% (95% CI: 0.08-0.24) of patients experienced a progressive disease. These findings indicate that the combination of NPLD and ifosfamide yields a statistically significant response rate in advanced/metastatic STS with limited toxicity.