Neoadjuvant PD-1 blockade in combination with chemotherapy for patients with resectable esophageal squamous cell carcinoma.

Abstract

220 Background: Programmed death-1 (PD-1) blockade may induce tumor regression in patients with advanced esophageal squamous cell carcinoma (ESCC), but little is known about the efficacy of PD-1 blockade in neoadjuvant therapy of resectable ESCC. Methods: Under an approved clinical trial protocol, a pilot study was conducted by enrolling patients with untreated, resectable (stage II or IIIA) ESCC. After written informed consent, each patient received two 21-day cycles of neoadjuvant treatment with camrelizumab (200mg), albumin-paclitaxel (260mg/m2) and carboplatin (area under the curve = 5) followed by surgical resection about 6 weeks after the first dose. The primary end points were safety and feasibility. We also reported the objective response rate (ORR), disease control rate (DCR) and tumor pathological response. Results: Between January 19, 2020, and July 21, 2020, we assessed 35 patients for screening, of whom 20 patients were enrolled. Neoadjuvant combination of camrelizumab, carboplatin and albumin-paclitaxel had an acceptable side-effect profile, and was not associated with delays in surgery. The ORR was 85%, and the DCR was 100%. Eighteen (90%) patients were taken into the surgery, and all of them successfully underwent R0 resection. Five (5/18 = 27.8%) patients had a pathological complete response (pCR), and eight (44.4%) patients had major pathological responses (MPR).The most common treatment-related grade 1–2 adverse events were leukopenia (12, 60%), neutropenia (11, 55%) and nausea (8, 40%). Two (10%) patients suffered grade 3 neutropenia. There was no grade 4 adverse events and treatment-related deaths. Conclusions: Neoadjuvant camrelizumab plus carboplatin and albumin-paclitaxel had manageable treatment-related toxic effects, did not delay surgery. This regimen induced pCR or MPR in 72.2% of resected tumor, demonstrating its antitumor efficacy in resectable ESCC. Clinical trial information: ChiCTR2000028900.