11512 Background: To date, there is no established maintenance strategy for patients with advanced soft tissue sarcoma (STS) who achieve disease control following first-line anthracycline-based chemotherapy. Maintenance therapy is therefore under active investigation in this setting. This study assessed the efficacy and safety of toripalimab (a humanized anti-PD-1 monoclonal antibody) combined with anlotinib (a multitargeted tyrosine kinase inhibitor) as a maintenance treatment. Methods: Patients with advanced STS who achieved stable disease or a partial response after at least four cycles of first-line anthracycline-based chemotherapy were enrolled in this single-arm, phase 2 trial and received maintenance therapy with toripalimab (240 mg intravenously on day 1) and anlotinib (12 mg orally once daily on days 1–14) in 21-day cycles. The primary endpoint was the 24-week progression-free survival rate (PFSR 24w ), defined as the proportion of patients who remained free from disease progression through 24 weeks after initiation of maintenance therapy. Secondary endpoints included median progression-free survival (PFS), median overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety. Results: Between April 2022 and May 2025, a total of 52 patients were enrolled; one patient diagnosed with pathologically confirmed metaplastic carcinoma was excluded. As of December 26, 2025, the median follow-up duration was 20 months. The PFSR 24w was 74.5%. The median PFS was 12 months, and the median OS was not reached at the time of data cutoff. Durable partial responses were observed in patients with dedifferentiated liposarcoma (5/14), leiomyosarcoma (2/11), epithelioid sarcoma (2/4), myxofibrosarcoma (1/3), synovial sarcoma (1/3), and pleomorphic rhabdomyosarcoma (1/1), resulting in an ORR of 23.5%. The most common grade 3–4 adverse events were hypertension (n = 10), increased gamma-glutamyltransferase (n = 5), hand-foot skin reaction (n = 3), and hypertriglyceridemia (n = 3). No new safety signals emerged during the course of the trial. Conclusions: Toripalimab in combination with anlotinib as maintenance therapy demonstrated promising efficacy and a manageable safety profile in patients with advanced STS following first-line anthracycline-based chemotherapy. Clinical trial information: ChiCTR2100054901.
Deng et al. (Wed,) studied this question.