3125 - Efficacy and Safety of the Combination of Tislelizumab with Chemoradiotherapy in Oligorecurrence Esophageal Squamous Cell Carcinoma: A Prospective Phase II Study

Z. Zheng¹, X. M. Wang², X. Liu³, Y. D. Zhao², N. Yu⁴, ?. ?^4,5, G. Feng⁴, J. Qin⁶, X. Kang¹, Y. Li⁶, Z. Wang⁶, X. Chen⁶, R. Zhang⁶, Q. Zheng⁶, N. BI⁴, Y. Li⁶, and X. Wang⁷; ¹National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, ²Department of Radiation Oncology, Anyang Tumor Hospital, Anyang, China, ³Binzhou Peoples Hospital, Binzhou, China, ⁴Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, ⁵Cancer Hospital Chinese Academy of Medical Sciences, Beijing, China, ⁶Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, ⁷Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing, China

Purpose/Objective(s): The postoperative recurrence and metastasis rate of esophageal squamous cell carcinoma (ESCC) remains high and prognosis were poor. PD-1 immune checkpoint inhibitors have shown efficacy in targeting advanced esophageal cancer. This phase II study aims to explore the efficacy and safety of concurrent chemoradiotherapy and immunotherapy for ESCC patients with oligometastatic recurrence after radical surgery. Materials/

Methods: This phase II study enrolled ESCC patients from 3 hospitals in China, diagnosed oligometastatic recurrence after radical surgery. The 1st stage, with 10 patients enrolled, was designed to explore the safety level and the 2nd stage was to explore efficacy. The oligorecurrence is defined as progression occurring three months after the operation with no more than three metastatic regions. The local recurrence was defined as tumor bed or anastomotic recurrence. The regional lymph node recurrences were regarded as mediastinal region and celiac lymph, respectively. The distal recurrences were considered as supraclavicular, retroperitoneal region and other distal organs. All of the positive regional lymph nodes were collectively counted as one lesion if regional lymph node recurrences existed. Tisleizumab were delivered on D1,22. Nab-paclitaxel 150mg/m2(starting on D2,23) and cisplatin, 75mg/m2 (starting on D2-4,22-24), were administered for two cycles. The radiotherapy was delivered with 50.4-60Gy, 1.8-2Gy per fraction. After CRT, patients received Tisleizumab every 3 weeks for 3-6 months and 2-4 cycle consolidation chemotherapy. The primary endpoint was 1-year OS, the second endpoints were 1-year PFS, ORR and toxicities.
Results: Between Jan 2021 and May 2023, 50 patients were screened for enrolment and 44 patients met the eligibility criteria. The metastatic regions were made up by the local (15.9%), regional (47.7%), distal (13.6%) and mixed recurrence (22.7%). In the 1st stage, one patient had a grade-3 Immune-related erythra out of ten patients. All patients were delivered chemoradiotherapy, 36 (81.8%) patients had completed two cycles of immunotherapy. The ORR rate was 84.1%. During concurrent chemoradiotherapy, the incidence of grade=3 treatment-related adverse events was nausea (9.1%), vomit (4.5%), anorexia (4.5%), leukopenia (13.6%), hepatitis (2.3%), radiation esophagitis (11.4%), erythra (4.5%).There were 5 cases of Immune-related adverse, including 2 cases of erythra, 1 case of hypothyroidism, hepatitis, gastroenteritis, respectively. With the median follow-up time of 19 months (range:4-30 months), 1-year OS and PFS was 83.2% and 73.8%. The median OS and the median PFS were not reached.
Conclusion: Concurrent chemoradiotherapy and immunotherapy yielded satisfactory 1-year OS rate and manageable toxicities in oligometastatic recurrence patients with ESCC after radical surgery.