Anlotinib versus placebo as adjuvant therapy for localized high-grade soft tissue sarcomas: a phase 2, double-blinded, randomized controlled trial

Abstract Purpose: We aimed to investigate the efficacy and safety of anlotinib as adjuvant targeted therapy for completely resected localized high-grade soft-tissue sarcomas (STS). Patients and Methods: Patients with localized high-grade STS after complete resection were randomly assigned in a 1:1 ratio to receive either oral 12 mg anlotinib or placebo once daily on days 1 to 14 every 21 days as a cycle, with up to six cycles until disease relapse, unmanageable toxicity, or death. The efficacy and safety were analyzed. This trial was the first trial exploring adjuvant targeted therapy for STS (NCT03951571). Results: Between June 2019 and November 2023, 88 patients were randomly assigned to receive anlotinib (n = 44) or placebo (n = 44). With a median follow-up of 30.95 months, the 1- and 2-year disease-free survival rates were 88% and 77% in the anlotinib group compared with 64% and 58% in the placebo group, respectively. Compared with patients treated with surgery alone, patients receiving adjuvant anlotinib combined with surgery had a reduced risk of disease recurrence [HR, 0.47; 95% confidence interval (CI), 0.22–1.00; P = 0.0445]. Based on the tumor histology, the reduced risk of disease recurrence with anlotinib versus placebo was observed in patients with myxofibrosarcoma (HR, 0.54; 95% CI, 0.17–1.65; P = 0.2698) and undifferentiated pleomorphic sarcoma (HR, 0.58; 95% CI, 0.12–2.87; P = 0.4971). Four patients discontinued anlotinib: two for proteinuria/hematuria (2/44, 5%) and two for poor healing of surgical wound (2/44, 5%). Conclusions: Compared with surgery alone, adjuvant anlotinib following surgery reduces the incidence of disease relapse in localized high-grade STS, with acceptable toxicity.