1225P - Neoadjuvant therapy of camrelizumab combined with chemotherapy in patients (pts) with resectable esophageal squamous cell cancer (ESCC): Preliminary results of a preoperative phase exploratory clinical trial

Background

The study aimed to evaluate the efficacy and safety of neoadjuvant therapy of camrelizumab, an anti-PD-1 antibody, combined with chemotherapy in resectable ESCC pts.

Methods

In this single-center, single-arm, exploratory clinical trial, treatment naïve pts with histologically identified resectable ESCC (cT1b-cT2 N+ or cT3-cT4aNany) were included. Eligible pts were treated with camrelizumab (200 mg, d1) combined with nab-paclitaxel (100 mg/m², d1 and d8) and nedaplatin (75 mg/m², d1) for 2 cycles (21 days per cycle). Radical surgery was conducted in the following 4-6 weeks. Primary endpoints were pathological complete response (pCR) rate, defined as the absence of residual cancer cells and negative lymph nodes metastasis in tumor area, and major pathologic response (MPR), defined as ≤10% residual viable tumor cells in resected tissue. Seventy pts would be enrolled in this study.

Results

From Aug 13, 2021, to Feb 12, 2022, a total of 28 pts were enrolled in this study. Twenty seven pts completed the two-cycle neoadjuvant therapy, with one pt discontinued the 2^nd cycle neoadjuvant therapy for intolerable toxicity. As of Apr 19, 2022, there were 6 complete response (CR), 14 partial response (PR), and 7 stable disease (SD) per RECIST 1.1, thus, the objective response rate (ORR) was 74.1%. Then, 24 of 28 (85.7%) pts underwent scheduled surgery, as 4 pts refused surgery. Of the 24 pts who underwent radical surgery, the pCR and MPR rate were 41.7% and 66.7%, respectively. According to tumor regression grade, 8/24 (33.3%) pts had TRG0, 8/24 (33.3%) TRG1, 5/24 (20.9%) TRG2, and 3/24 (12.5%) TRG3. The most common AEs were lymphocyte count decreased (LCD,92.9%), hypoalbuminemia (75.0%), anemia (71.4%). Most AEs were grade 1-2. Grade 3 AEs included 5 (17.9%) neutrophil count decreased, 4 (14.3%) LCD, 3 (10.7%) white blood cell count decreased, 1 (3.6%) alanine aminotransferase increased, 1 (3.6%) hyperkalemia and 1 (3.6%) platelet count decreased. No grade 4/5 AEs occurred.

Conclusions

Neoadjuvant therapy of camrelizumab combined with chemotherapy has promising efficacy and good safety in ESCC pts.

Clinical trial identification

ChiCTR2100050057 2021.8.13.

Editorial acknowledgement

Legal entity responsible for the study

Yinjun Dong.

Funding

Jiangsu Hengrui Pharmaceutical Co. LTD.

Disclosure

All authors have declared no conflicts of interest.