The Association Between Stk11/Lkb1 And/Or Keap1 Mutations And Response To Pd-1/Pd-L1 Inhibitors In Patients With Advanced Non-Small Cell Lung Cancer (Nsclc).

e21538 Background: Advanced non-small cell lung cancer (NSCLC) patients with tumors harboring STK11/LKB1 or KEAP1 mutations have inferior treatment outcomes when treated with PD-1/PD-L1 blockade, regardless of KRAS status, PD-L1 score, or TMB score (Skoulidis et al, Cancer Discovery 2018, ASCO abstract 102, 2019). Methods: Retrospective clinical databases from Indiana University and Karmanos Cancer Institute were queried to identify patients from 2008-2019 with advanced NSCLC treated with PD-1/PD-L1 monotherapy (group A) or concurrent chemotherapy + PD-1/PD-L1 inhibitors (group B) whose tumors harbored STK11/LKB1 and/or KEAP1 mutations. Patients were characterized by best response, progression of disease (PD) or non-PD (complete response (CR) + partial response (PR) + stable disease (SD)). Patient and disease characteristics, response, and duration of response (> vs. < 6 months) were recorded. Results: A total of 77 patients met the above criteria (55 in group A, 22 in group B). 52 of 55 patients in group A received prior chemo. Patient and disease characteristics and outcomes are summarized in the table. Conclusions: STK11/LKB1 and/or KEAP1 mutations are independent of PD-L1/TMB status, although most patients had PD-L1 of <1%. Nearly ½ of patients with STK11/LKB1 and/or KEAP1 mutations achieve at least SD with PD-1/PD-L1 inhibitor monotherapy and more than 50% of those with non-PD maintain that response status for > 6 mos. The frequency and duration of non-PD in this population is higher in patients receiving chemotherapy + PD-1/PD-L1 concomitantly. [Table: see text]