Efficacy of anti-PD-1 therapy for recurrence after chemoradiotherapy in locally advanced NSC LC

Chemoradiotherapy (CRT) is the standard treatment for locally advanced non-small cell lung cancer (NSCLC). Recently, anti-PD-1 antibody therapy became a key treatment for stage IV NSCLC as the combination of immune checkpoint inhibitors (ICIs) and platinum doublet chemotherapy. However, the efficacy and toxicity of anti-PD-1 therapy for recurrence after CRT in stage III NSCLC are not well examined.

Patients who received anti-PD-1 therapy for recurrence after CRT were identified in our clinical database. The safety and efficacy of anti-PD-1 therapy were retrospectively analyzed.

From March 1, 2013 to April 30, 2018, there were 20 patients who received anti-PD-1 therapy for recurrence after CRT. The median duration from CRT to initial anti-PD-1 therapy was 9.3 months. 12 patients (60%) were alive and 7 patients (35%) were still receiving anti-PD-1 therapy at the data cutoff point (median follow-up, 13.5 months). The ORR for anti-PD-1 therapy was 45.0%. Median progression-free survival (PFS) and overall survival (OS) from initiation of anti-PD-1 therapy was 8.4 months and 26.2 months, respectively. PFS in patients who had a short interval from last CRT to initial anti-PD-1 therapy seemed to have better outcomes (duration from last CRT to initial anti-PD-1 therapy < 9.3 months vs. ≥ 9.3 months; median PFS, 17.0 months vs. 4.9 months). Grade 3 or 4 immune-related adverse events occurred in 5% of patients. Only grade 1 pneumonitis was observed.

The efficacy of anti-PD-1 therapy for recurrence after CRT in stage III NSCLC might better than in stage IV NSCLC. The duration from CRT to initial anti-PD-1 therapy might be related to efficacy.