Clinical outcomes of maintenance durvalumab after definitive concurrent chemoradiotherapy in unresectable locally advanced stage III non-small cell lung cancer according to epidermal growth factor receptor and anaplastic lymphoma kinase status: Korean Cancer Study Group LU-22-18.

person Dae-Ho Choi Department of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea info_outline Dae-Ho Choi, Myung-Ju Ahn, Miso Kim, Young Saing Kim, Keon Uk Park, Jang Ho Cho, Hongsik Kim, Ki Hyeong Lee, Heejoon Ahn, Il-Hwan Kim, Kyung-Hee Lee, Gyeong-Won Lee, Seong Yoon YI, Beung Chul AHN, Min-Young Lee, Hyun Ae Jung, Sehhoon Park, Jong-Mu Sun, Jin Seok Ahn, Se-Hoon Lee

Authors person Dae-Ho Choi Department of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea info_outline Dae-Ho Choi, Myung-Ju Ahn, Miso Kim, Young Saing Kim, Keon Uk Park, Jang Ho Cho, Hongsik Kim, Ki Hyeong Lee, Heejoon Ahn, Il-Hwan Kim, Kyung-Hee Lee, Gyeong-Won Lee, Seong Yoon YI, Beung Chul AHN, Min-Young Lee, Hyun Ae Jung, Sehhoon Park, Jong-Mu Sun, Jin Seok Ahn, Se-Hoon Lee Organizations Department of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea, Seoul National University Hospital, Seoul, South Korea, Division of Medical Oncology, Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, South Korea, Keimyung University School of Medicine, Daegu, South Korea, Division of Oncology, Department of Internal Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Incheon, South Korea, Division of Hematology-Oncology, Department of Internal Medicine, Chungbuk National University Hospital, Cheongju, South Korea, Chungbuk National University Hospital, Chungbuk National University College of Medicine, Cheongju, South Korea, Division of Hematology and Oncology, Department of Internal Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, South Korea, Inje University Haeundae Paik Hospital (Korea, Republic of), Haeundae-Gu, South Korea, Yeungnam University Medical Center, Daegu, South Korea, Department of Internal Medicine, Gyeongsang National University College of Medicine, Jinju, South Korea, Ilslan Paik Hospital, Inje University, Gyeonggi-Do, South Korea, Center for Lung Cancer, Division of Hematology and Oncology, Department of Internal Medicine, Research Institute and Hospital, National Cancer Center, Goyang-Si, South Korea, Division of Hematology and Oncology, Department of Internal Medicine, Soonchunhyang University Seoul Hospital, Seoul, South Korea, Samsung Medical Center, Gangnam-Gu, South Korea, Samsung Medical Center, Seoul, South Korea, Department of Internal Medicine, Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea Abstract Disclosures Research Funding No funding sources reported Background: The role of maintenance durvalumab after definitive concurrent chemoradiotherapy (CCRT) in unresectable locally advanced non-small cell lung cancer (NSCLC) with epidermal growth factor receptor ( EGFR ) mutation or anaplastic lymphoma kinase ( ALK ) translocation remains unclear. We compared the effectiveness of durvalumab maintenance therapy in groups with EGFR/ALK wild-type versus those with EGFR or ALK mutations. Methods: In this retrospective multicenter observational study, patients with locally advanced NSCLC without progression after CCRT followed by maintenance durvalumab and available molecular test results ( EGFR and ALK ) were eligible. The primary objective was to compare progression-free survival (PFS) between EGFR / ALK wild-type and EGFR or ALK mutant NSCLC. Secondary objectives include overall survival according to EGFR or ALK mutation and programmed cell death-ligand 1 (PD-L1) expression. Results: Among 339 patients, 279 had wild-type EGFR/ALK , 41 had EGFR mutations and 19 had ALK translocations. The median age was 68 years with 276 males (81.4%) and 63 females (18.6%), 165 (49.3%) had adenocarcinoma, 149 (44.5%) had squamous cell carcinoma, and 21 (6.3%) had other histological types, 120 (35.4%) had stage IIIA, 168 (49.6%) stage IIIB, and 51 (15.0%) had stage IIIC. The majority of patients (n=288, 85%) achieved partial response to CCRT, 2 (0.6%) had a complete response, and 49 patients (14.4%) had stable disease. Excluding 4 patients with unknown PD-L1 tumor proportion score (TPS), 16 (4.8%) had a PD-L1 TPS of 0, 168 (50.1%) had 1-49, and 151 (45.1%) had 50 or higher. The median PFS was 21.4 months (95% CI 17.3–25.3) for the EGFR / ALK wild-type group and 21.0 months (95% CI 15.7–NA) for the EGFR or ALK mutant group with no significant difference (p=0.74). Significant differences occurred in PFS based on PD-L1 expression with values of 13.6 (95% CI 10.5–NA), 18.7 (95% CI 15.1–26.9), and 24.7 (95% CI 20.7–NA) months for TPS of 0, 1–49, and 50 or higher, respectively (p=0.02). Conclusions: Durvalumab maintenance therapy after definitive CCRT in unresectable locally advanced NSCLC patients with EGFR or ALK mutation demonstrates comparable clinical outcomes to those with wild-type EGFR/ALK when PD-L1 expression is present.