Efficacy and safety of camrelizumab plus apatinib in patients with advanced esophageal squamous cell carcinoma previously treated with immune checkpoint inhibitors (CAP 02 Re-challenge): A single-arm, phase II study.

Background: With the increasing use of immune checkpoint inhibitors (ICIs) in advanced esophageal squamous cell carcinoma (ESCC), there remains an unmet need for options to address disease progression after prior ICIs. This single-arm phase II study evaluated the efficacy and safety of re-challenge with camrelizumab plus apatinib in patients with advanced ESCC who were previously treated with ICIs.

Methods: This study enrolled patients aged 18-75 years with unresectable locally advanced, locally recurrent, or distant metastatic ESCC who received prior ICIs. Patients received intravenous camrelizumab 200 mg every 2 weeks and oral apatinib 250 mg daily until disease progression, unacceptable toxicity, or consent withdrawal. The primary endpoint was the investigator-assessed confirmed objective response rate (ORR).

Results: Between September 1, 2021 and March 29, 2023, 49 eligible patients were enrolled and received treatment. Among the 49 patients, the confirmed ORR was 10.2 % (95 % CI 3.4-22.2), the disease control rate (DCR) was 69.4 % (54.6-81.7), the median progression-free survival (PFS) was 4.6 months (95 % CI 3.8-6.5) and overall survival (OS) was 7.5 months (5.5-13.6). Grade ≥ 3 treatment-related adverse events occurred in 17 patients (34.7 %). No treatment-related deaths occurred.

Conclusions: This study showed that the confirmed ORR was modest and did not reach clinically meaningful improvement for patients with ESCC who were previously treated with ICIs, with a manageable safety profile.