Multicenter randomized phase 2 trial of tislelizumab with induction chemotherapy and concurrent chemoradiotherapy in locally advanced ESCC

The phase 2 EC-CRT-002 trial, at four centers in China, evaluated the efficacy and safety of addition of tislelizumab to induction chemotherapy and concurrent chemoradiotherapy (CRT), with or without maintenance immunotherapy, in patients with unresectable locally advanced esophageal squamous cell carcinoma (ESCC). Adult patients with newly diagnosed, unresectable stage II to IVB ESCC were randomized 1:1 to receive two cycles of paclitaxel-cisplatin induction chemotherapy followed by CRT in combination with tislezizumab for 16 cycles in group A (two induction, two concurrent, and 12 maintenance) or four cycles in group B (two induction and two concurrent). The primary endpoint was progression-free survival (PFS) compared with historical control. Both groups consisted of 57 patients. After a median follow-up of 22.7 months (IQR 16.2-28.2), group B demonstrated significantly better outcomes versus controls, while group A showed no benefit. Grade ≥ 3 adverse events occurred in 86.0% of group A and 80.7% of group B. The authors conclude that the addition of tislelizumab to induction chemotherapy and concurrent CRT without maintenance immunotherapy demonstrated superior efficacy and manageable toxicity in locally advanced ESCC.