Feasibility and tolerability of anlotinib plus PD-1 blockades as rechallenge immunotherapy in previously treated advanced ESCC: a retrospective study

Abstract Background Rechallenge with immune checkpoint inhibitor (ICI) seemed favorable in several tumors, but clinical experience on esophageal squamous cell carcinoma (ESCC) was scanty. This real-world study aimed to assess the feasibility and safety of anlotinib plus ICI for patients with previously ICI-treated advanced ESCC. Materials and Methods We retrospectively identified advanced ESCC patients who received anlotinib plus ICI in the rechallenge setting for evaluation of clinical outcomes and safety. Totally 110 ICI-pretreated patients, of which 89 (80.9%) received prior first- or second-line treatment, were included from September 9, 2019, to November 30, 2022. Most patients (63.6%) discontinued initial ICI due to disease progression. Results After rechallenge, median overall survival (OS) and progression-free survival (PFS) were 11.1 (95% CI, 8.6-13.7) and 5.6 (95% CI, 4.4-6.8) months, respectively; estimated OS and PFS rates at 12 months were 47.6% (95% CI, 36.8%-57.7%) and 21.4% (95% CI, 10.9%-34.2%), respectively. No complete response was reported and 21 (19.1%) patients attained partial response; the objective response rate was 19.1%. Fifty-five (50.0%) had stable disease for a disease control rate of 69.1%. Of the 21 responders, median duration of response was 6.4 months. Tendencies for longer OS were observed in patients with Eastern Cooperative Oncology Group Performance of 0 (P = .056). The incidence of grade 3 or higher treatment-related adverse events was 10.0%. Conclusion Anlotinib plus ICI in the rechallenge setting was promising and resulted in encouraging benefits for patients with previously ICI-treated advanced ESCC. Our findings provided preliminary but unique evidence to help select ESCC patients benefiting from this strategy. Trial registration chictr.org.cn; number ChiCTR2300070777