Top Line: When adding a PD-1 inhibitor onto definitive chemoradiation for unresectable locally advanced esophageal squamous cell carcinoma (ESCC), does adding a year of maintenance immunotherapy improve outcomes?
The Study: Definitive CRT remains the backbone for unresectable locally advanced ESCC, but outcomes remain unsatisfying, and the optimal way to fit in immunotherapy (induction, concurrent, maintenance, or all three) is unsettled. EC-CRT-002 is a phase 2 trial that treated 114 patients with unresectable stage ESCC to tislelizumab (PD-1 inhibitor) + two cycles of induction paclitaxel/cisplatin followed by concurrent weekly paclitaxel/cisplatin with IMRT to 50.4 Gy in 28 fractions. They were randomized to receive 12 cycles of maintenance tislelizumab or no maintenance therapy. Each arm was compared against a historical control from the investigators' prior trial (1-yr PFS 56%). The results were a little surprising. Compared to historical control, maintenance therapy had no significant improvement in 1 year PFS (52.6%). However, there was a significant improvement in the no-maintenance arm with a 1 year PFS rate of 71.9%, a complete response rate of 70.2%, and even improved OS (HR 0.42). What gives? The authors blame some of the maintenance arm’s underperformance on a baseline imbalance in NRF2 pathway mutations (a known radioresistance signal) plus added maintenance toxicity and a possibility that the immune system was already sufficiently primed during induction. Ultimately, with small size and historical comparison, these results are phase 3 hypothesis generating rather than a strong verdict.
TBL: Front-loading tislelizumab with induction chemo and concurrent CRT looks promising in unresectable locally advanced ESCC, but a year of maintenance immunotherapy on top added toxicity without improving treatment outcomes. | Chen, J Clin Oncol 2026
The Study: Definitive CRT remains the backbone for unresectable locally advanced ESCC, but outcomes remain unsatisfying, and the optimal way to fit in immunotherapy (induction, concurrent, maintenance, or all three) is unsettled. EC-CRT-002 is a phase 2 trial that treated 114 patients with unresectable stage ESCC to tislelizumab (PD-1 inhibitor) + two cycles of induction paclitaxel/cisplatin followed by concurrent weekly paclitaxel/cisplatin with IMRT to 50.4 Gy in 28 fractions. They were randomized to receive 12 cycles of maintenance tislelizumab or no maintenance therapy. Each arm was compared against a historical control from the investigators' prior trial (1-yr PFS 56%). The results were a little surprising. Compared to historical control, maintenance therapy had no significant improvement in 1 year PFS (52.6%). However, there was a significant improvement in the no-maintenance arm with a 1 year PFS rate of 71.9%, a complete response rate of 70.2%, and even improved OS (HR 0.42). What gives? The authors blame some of the maintenance arm’s underperformance on a baseline imbalance in NRF2 pathway mutations (a known radioresistance signal) plus added maintenance toxicity and a possibility that the immune system was already sufficiently primed during induction. Ultimately, with small size and historical comparison, these results are phase 3 hypothesis generating rather than a strong verdict.
TBL: Front-loading tislelizumab with induction chemo and concurrent CRT looks promising in unresectable locally advanced ESCC, but a year of maintenance immunotherapy on top added toxicity without improving treatment outcomes. | Chen, J Clin Oncol 2026