118P Role of PD-L1 and pathological complete response (pCR) with neoadjuvant (NEO) or perioperative (PERIOP) immune-checkpoint inhibitors (ICI) and platinum-based chemotherapy (PCT) in resectable non-small cell lung cancer (NSCLC): A systematic review and metanalysis

A previous metanalysis showed no significant subgroup interaction between PD-L1 and pCR, while both PD-L1 status and pCR significantly correlated with better event free survival (EFS). Overall, no difference in EFS between NEO and PERIOP strategies was reported by indirect comparison (Nuccio et al). Additional RCTs and updated results of previous studies could help to define the role of PD-L1 and pCR and the best treatment strategy according to these variables. PubMed, Embase and Cochrane were searched until 11/2023 for RCTs comparing NEO or PERIOP ICI + PCT with NEO PCT in patients (pts) with resectable NSCLC. Association between PD-L1 tumor proportional score (TPS) and pCR and correlation between PD-L1, pCR and EFS was assessed. Indirect comparison between PERIOP and NEO strategies was performed in PD-L1 and pCR subgroups. 8 RCTs (n=3407) were included. PERIOP/NEO significantly improved both pCR (χ2 = 10.45, p < 0.00001, I2= 33%) and EFS (χ2 = 6.33, p < 0.00001, I2= 5%).There was a significant subgroup interaction for pCR by PD-L1 TPS (<1%, 1-49% and ≥50%: χ2 = 6.44, p = 0.04, I2=68.9%). EFS significantly correlated with PD-L1 status (TPS <1% vs 1-49% vs ≥50%: χ2 = 13.28, p = 0.001, I2=84.9%) and pCR (χ2 =18.96, p < 0.0001, I2=94.7%). No difference in EFS between PERIOP and NEO strategies was observed either according to PDL1 status [TPS <1%: HR 1.03 (95% CI 0.68-1.56); 1-49%: HR 1.85 (95% CI 0.96-3.58); ≥50%: HR 1.54 (95% CI 0.77-3.05)] or according to pCR [pCR: HR 2.36 (95% CI 0.72-7.68); no-pCR: HR 0.86; (95% CI 0.60-1.23)]. Table: 118PpCR (RR)χ2p valueEFS (HR)χ2p valueOverall5.65 [4.09, 7.82]10.45< 0.000010.59[0.52, 0.67]6.33< 0.00001Pathological responseno-pCRNot applicable0.75 [0.64, 0.87]18.96< 0.0001pCR0.19 [0.11, 0.35]PD-L1<1%3.70 [2.41, 5.71]6.440.040.75 [0.62, 0.914.20.041-49%5.42 [2.66, 11.04]0.56 [0.42, 0.75]≥50%8.25 [5.30, 12.83]0.38 [0.28, 0.56] Open table in a new tab Updated results of previous studies and additional RCTs showed that PD-L1 status significantly correlates both with pCR and EFS and confirmed the achievement of pCR as a predictor of EFS benefit. NEO and PERIOP are equivalent strategies in all different PD-L1 and pCR categories.