Switch maintenance therapy with anlotinib after chemotherapy in unresectable or metastatic soft tissue sarcoma: a single-center retrospective study.

Background Chemotherapy is an important first-line treatment option in patients with advanced soft tissue sarcoma (STS). Whether maintenance therapy improves survival after chemotherapy is still controversial. Methods We retrospectively analyzed the data of 21 adults diagnosed with unresectable or metastatic STS between May 2018 and September 2019 in our center. They achieved an objective response or stable disease after chemotherapy and then received at least one cycle of switch maintenance therapy with anlotinib, a novel multi-targeted tyrosine kinase inhibitor. The objective response rate (ORR), disease control rate (DCR), adverse events, and median progression-free survival (PFS) after anlotinib maintenance (PFSa), and the median PFS after chemotherapy (PFSc) were analyzed. Results Nineteen patients received first-line chemotherapy and 2 received second-line chemotherapy. Five patients achieved a partial response and 16 had stable disease after chemotherapy. The median number of anlotinib maintenance cycles was five (range, 2-31). One patient achieved a complete response and two patients exhibited a partial response during anlotinib maintenance, with an ORR of 14.3%. The DCR was 81.0%. After a median follow-up of 14.0 months, the median PFSa and PFSc were 7.3 and 13.6 months, respectively. Grade 3/4 adverse events occurred in six (28.6%) patients and were managed through symptomatic treatment, dose reduction or anlotinib discontinuance. Conclusion Our results indicate that switch maintenance therapy with anlotinib is a promising strategy for the treatment of patients with unresectable or metastatic STS who have benefited from chemotherapy. Toxicities were manageable. Prospective clinical trials are needed to confirm this finding.