Immune checkpoint inhibitors versus second line chemotherapy for patients with lung cancer refractory to first line chemotherapy.

Purpose: Anti Programmed Death-ligand (PD1/PD-L1) directed immune-checkpoint-inhibitors (ICI) are widely used to treat patients with advanced non-small cell lung cancer (NSCLC) who progress after first line chemotherapy. The best strategy after early progression under first line has not been specifically studied.

Patients And Methods: We conducted a multicenter, retrospective study including all consecutive NSCLC patients progressing within the first 3 months following introduction of first-line chemotherapy and being treated with second line ICI monotherapy or chemotherapy between March 2010 and November 2017. We analysed the clinicopathological data and outcome under second line chemotherapy vs. second line ICI: objective response rate (ORR), progression-free survival (PFS), overall survival (OS.

Results: We identified 176 patients with refractory disease, 99 who received subsequent immunotherapy and 77 undergoing chemotherapy. The 2 populations were comparable regarding the main prognostic criteria, median age was 60, main histology was adenocarcimoma (68.2%). PFS was not significantly different between both treatments 1.9 [1.8-2.1] versus 1.6 month [1.4-2.0] (P=0.125). Compared to chemotherapy, ICI treated patients had a superior OS (P=0.03) (Median [95% CI] OS 4.6 [2.8-6.7] versus 4.2 months [3.4-5.9] and a non-significant improvement in ORR (17.2% versus 7.9%, respectively, P=0.072). Poor performance status (ECOG PS≥2) and a higher number of metastatic sites (≥3) were associated with poorer prognosis. KRAS-mutated patients did not seem to benefit more from ICI than chemotherapy.

Conclusions: ICI appears to be the preferred second-line treatment for patients who are refractory to first line chemotherapy.