Lactate dehydrogenase and baseline markers associated with clinical outcomes of advanced esophageal squamous cell carcinoma patients treated with camrelizumab (SHR-1210), a novel anti-PD-1 antibody.

Abstract

e15559 Background: A small proportion of patients with advanced esophageal squamous cell carcinoma (ESCC) could benefit from immune checkpoint inhibitors, and reliable peripheral blood biomarkers for outcomes of anti-PD-1 immunotherapy were not identified in ESCC. Methods: A total of 43 patients were retrospectively reviewed in the ESCC cohort of a phase I trial from our center. All patients received intravenous camrelizumab (SHR-1210), a novel anti-PD-1 antibody, at a dose of 60 mg, 200 mg or 400 mg (4-week interval after first dose followed by a 2-week schedule) and repeated every two weeks until disease progression or intolerable toxicity. The associations between lactate dehydrogenase (LDH) as well as other peripheral blood biomarkers at baseline and the efficacy of camrelizumab were also investigated. Results: With a median follow-up of 19.6 months, the overall response rate was 25.6% (11/43), including one complete response. Median progression-free survival (PFS) and overall survival were 2.0 months (95% CI: 0-4.1 months) and 8.0 months (95% CI: 7.2-8.8 months), respectively. Notably, four patients achieved a PFS exceeding 12 months, including three patients with a long-lasting duration of response over 1 year. Patients with an elevated baseline lactate dehydrogenase had lower tumor response rates (8.3% vs. 32.3%, p = 0.02) as well as shorter PFS (median: 1.8 vs. 4.0 months; HR 0.39, p = 0.002) and overall survival (median: 4.2 vs. 10.4 months; HR 0.22, p < 0.0001) compared with patients with normal levels. An increase of lactate dehydrogenase level during treatment was significantly associated with disease progression (p = 0.014). Multivariate Cox analysis identified LDH (HR = 0.18), C-reactive protein (HR = 0.27), number of involved organs (HR = 0.31), absolute monocyte count (HR = 0.33) and Eastern Cooperative Oncology Group performance status (HR = 0.36) as independent prognostic factors. Conclusions: Serum LDH, as is readily available in routine clinical practice, is a potential marker for response and a powerful independent factor for survival in advanced ESCC patients receiving anti-PD-1 treatment.