103P - Tislelizumab combined with chemoradiotherapy for locally advanced esophageal squamous cell carcinoma: A multicenter, prospective, single-arm, real-world study

Background

Though definitive chemoradiotherapy(dCRT) is the standard of care for unresectable esophageal squamous cell carcinoma (ESCC), there are still 30-40% of patients with distant metastasis. Immunotherapy (IO) has been proven to be effective for patients with advanced metastasis ESCC. It is of great clinical value to discover the combination mode of CRT and IO in the real world, and to evaluate its efficacy and safety for optimizing the treatment strategy in the subsequent clinical practice.

Methods

This is a multicenter, single-arm, prospective real-world study. We planned to enroll patients with newly diagnosed locally advanced ESCC who were unresectable or refused surgery. Patients who had not received previous anti-tumor therapy (surgery, radiotherapy, chemotherapy, IO). Patients were expected to receive at least 2 cycles of tislelizumab. The primary endpoint was 2-year survival. Secondary endpoints were ORR, PFS, TRAE, and irAE.

Results

From March 2022 to November 2023, a total of 58 patients with locally advanced unresectable ESCC were enrolled in 15 centers. The average age was 61 years, and stage II, III, and IVa accounted for 22%, 38%, and 40%, respectively. In the real world, there were three treatment modes of IO combined with CRT, including concurrent CRT combined with IO, IO sequential consolidation therapy after CRT, and IO combined with chemotherapy induction followed by CRT, with the proportions of 48%, 21%, and 31%, respectively. A total of 53 patients were evaluated for efficacy, with an ORR of 79% and a DCR of 100%. As of the data cutoff date, a total of 8 patients had progressed and 10 patients had died. The 1-year PFS rate was 75.8%, and the 1-year OS rate was 81.2%. Most of the adverse events were grade 1-2, and grade 3 TRAE occurred in 4 patients, including 1 case of radiation pneumonitis, 1 case of immune pneumonitis, 1 case of esophagitis and 1 case of platelet inhibition. One patient died of esophageal fistula. Three patients withdrew from treatment due to adverse reactions.

Conclusions

For patients with unresectable locally advanced ESCC, dCRT combined with immunotherapy has good efficacy and controllable safety in the real world.

Clinical trial identification

ChiCTR2200059190.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.