Durvalumab following definitive chemoradiotherapy among patients with stage III NSCLC in Thai populations: a real-world, multi-center observational study

Piyada Sitthideatphaiboon¹Thanyanan Reungwetwattana²Sureerat Jaruhathai³Archara Supavavej⁴Piyarat Limpawittayakul⁴Kunlatida Maneenil⁵Krittiya Korphaisarn⁶Thatthan Suksombooncharoen⁷LUANGYOT THONGTHIEANG⁸Chirawadee Sathitruangsak⁹Chawalit Chayangsu¹⁰Hataiwan Ratanabunjerdkul¹¹Naiyarat Prasongsook^12*Virote Sriuranpong^1*

• ¹King Chulalongkorn Memorial Hospital, Bangkok, Thailand
• ²Mahidol University Faculty of Medicine Ramathibodi Hospital Department of Clinical Epidemiology and Biostatistics, Bangkok, Thailand
• ³Police General Hospital, Bangkok, Thailand
• ⁴Chulabhorn Hospital, Bangkok, Thailand
• ⁵Rajavithi Hospital, Bangkok, Thailand
• ⁶Mahidol University Faculty of Medicine Siriraj Hospital, Bangkok, Thailand
• ⁷Chiang Mai University, Faculty of Medicine, Chiang Mai, Thailand
• ⁸Khon Kaen Hospital, Khon Kaen, Thailand
• ⁹Prince of Songkla University, Hat Yai, Thailand
• ¹⁰Surin Hospital, Mueang Surin District, Thailand
• ¹¹Thammasat University Hospital, Khlong Nueng, Thailand
• ¹²Phramongkutklao Hospital, Bangkok, Thailand

Background: In locally advanced non-small cell lung cancer (LA-NSCLC), durvalumab as consolidation therapy following definitive chemoradiotherapy (CRT) was established as the standard of care. Given the heterogeneity of patients with LA-NSCLC, the present study evaluated the efficacy and safety of durvalumab in a real-world, multi-center observational study. Methods: Patients with LA-NSCLC, whose disease had not progressed following CRT and receiving ≥1 dose of durvalumab as part of the expanded access program (EAP) in Thailand and outside EAP were included. In addition to descriptive statistics, survival probability was determined using the Kaplan-Meier method. Results: 82 patients from 12 centers in Thailand were enrolled. The median age was 63 years, 74% were men, 72% had non-squamous NSCLC and 20% of patients had EGFR mutation. Only 13.4% of patients tested for programmed-death-ligand 1 (PD-L1) and 54.5% had PD-L1-expression. Most patients (84%) received concurrent CRT and carboplatin/paclitaxel was the most commonly used. 89% of patients received RT dose ≥60 Gy with median time of durvalumab initiation from the end of RT being 42 days. Overall, 57% of patients completed the 12-month treatment with median of 24 cycles. ORR and DCR were 41.3% and 86.7%, respectively. With median follow-up time of 43.3 months, 2-year PFS and 2-year PFS2 were 63.1% and 81.6%, respectively. Immune-related AEs (irAEs) of any grades and grade ≥3 were 25.6% and 9.8%, respectively. Pneumonitis was the most frequent irAEs (17%), and 6% were grade ≥3, leading to discontinuation in 6 patients (7.3%).