Phase II Study of TQB2450, a Novel PD-L1 Antibody, in Combination with Anlotinib in Patients with Locally Advanced or Metastatic Soft Tissue Sarcoma

PURPOSE: To explore the efficacy and safety of TQB2450 combined with anlotinib in patients with locally advanced or metastatic soft-tissue sarcoma (LA/M STS). PATIENTS AND METHODS: This was a single arm phase II study (TQB2450-Ib-02 study) performed at two hospitals in China to assess the potency of TQB2450 combined with anlotinib in patients with LA/M STS. Patients were previously unresponsive to at least one chemotherapy regimen. Anlotinib (12 mg every day) was administered orally from day 1 to day 14 every 3 weeks. TQB2450 was administered by intravenous infusion at 1,200 mg on day 1 every 3 weeks. The primary endpoint was the objective response rate (ORR). The secondary endpoints included progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and safety. RESULTS: Between January 2019 and June 2020, 30 patients were enrolled. The ORR was 36.67% and the DCR was 76.67%. The median PFS was 7.85 months [95% confidence interval (CI), 2.89–23.06] and the median OS was not reached [95% CI, 10.58–not estimable (NE)]. Among the patients with alveolar soft part sarcoma (ASPS; 12/30, 40%), the ORR was 75% and the median PFS was 23.06 months (95% CI, 8.97–NE). The most common treatment related adverse events were hypothyroidism (76.67%), hypertriglyceridemia (63.33%), hypercholesterolemia (60.00%), and elevated blood lactate dehydrogenase (53.33%). CONCLUSIONS: The study showed the promising activity in patients with ASPS, also indicating the trend of treatment efficacy in other sarcomas. The toxicity was tolerable. More studies with larger sample size and controlled arm were warranted.