Camrelizumab plus apatinib as second-line treatment for advanced oesophageal squamous cell carcinoma (CAP 02): a single-arm, open-label, phase 2 trial

Abstract

Background: Camrelizumab, an anti-PD-1 antibody, has shown moderate efficacy in oesophageal squamous cell carcinoma. Apatinib, a selective inhibitor of VEGFR2, has a synergistic effect with immunotherapy. We aimed to assess the combination of camrelizumab and apatinib as second-line treatment for advanced oesophageal squamous cell carcinoma.

Methods: This single-arm, open-label, phase 2 study was conducted at eight centres in China. Eligible patients were aged 18-75 years, with an Eastern Cooperative Oncology Group performance status of 0 or 1, who had unresectable locally advanced, locally recurrent, or metastatic oesophageal squamous cell carcinoma, and had progressed after or were intolerant to first-line chemotherapy. Patients received intravenous camrelizumab 200 mg once every 2 weeks plus oral apatinib 250 mg once daily for a 28-day cycle until disease progression, unacceptable adverse events, or withdrawal of consent. The primary endpoint was investigator-assessed confirmed objective response rate. Efficacy was analysed in patients who had received at least one dose of study drug, and safety was analysed in patients who received the study drug and had at least one post-baseline safety assessment. The study of this cohort is complete and this trial is registered with ClinicalTrials.gov, number NCT03736863.

Findings: Between Dec 5, 2019, and Feb 10, 2021, 52 patients were enrolled and included in analyses. At data cutoff (June 20, 2021), median follow-up was 7·5 months (IQR 4·0-11·2). 18 (34·6%, [95% CI 22·0-49·1]) of 52 patients had a confirmed objective response. 23 (44%) of 52 patients had grade 3 or worse treatment-related adverse events. The most common grade 3 or worse treatment-related adverse events were increased aspartate aminotransferase (10 [19%]), increased gamma-glutamyltransferase (10 [19%]), and increased alanine aminotransferase (five [10%]). No treatment-related deaths occurred.

Interpretation: Camrelizumab combined with apatinib showed promising activity and manageable toxicity, and might be a potential second-line treatment option for patients with advanced oesophageal squamous cell carcinoma. Another cohort of this study, enrolling patients previously treated with first-line immunotherapy, is ongoing.

Funding: Jiangsu Hengrui Pharmaceuticals.