Real-world prospective analysis of treatment patterns in durvalumab maintenance after chemoradiotherapy in unresectable, locally advanced NSCLC patients.

The aim of this prospective study is to evaluate the clinical use and real-world efficacy of durvalumab maintenance treatment after chemoradiotherapy (CRT) in unresectable stage, locally advanced non-small cell lung cancer (NSCLC). All consecutive patients with unresectable, locally advanced NSCLC and PD-L1 expression (≥1%) treated after October 2018 were included. Regular follow up, including physical examination, PET/CT and/or contrast-enhanced CT-Thorax/Abdomen were performed every three months after CRT. Descriptive treatment pattern analyses, including reasons of discontinuation and salvage treatment, were undertaken. Statistics were calculated from the last day of thoracic irradiation (TRT). Twenty-six patients were included. Median follow up achieved 20.6 months (range: 1.9-30.6). Durvalumab was initiated after a median of 25 (range: 13-103) days after completion of CRT. In median 14 (range: 2-24) cycles of durvalumab were applied within 6.4 (range 1-12.7) months. Six patients (23%) are still in treatment and seven (27%) have completed treatment with 24 cycles. Maintenance treatment was discontinued in 13 (50%) patients: 4 (15%) patients developed grade 3 pneumonitis according to CTCAE v5 after a median of 3.9 (range: 0.5-11.6) months and 7 (range: 2-17) cycles of durvalumab. Four (15%) patients developed grade 2 skin toxicity. One (4%) patient has discontinued treatment due to incompliance. Six and 12- month progression-free survival (PFS) rates were 82% and 62%, median PFS was not reached. No case of hyperprogression was documented. Eight (31%) patients have relapsed during maintenance treatment after a median of 4.8 (range: 2.2-11.3) months and 11 (range: 6-17) durvalumab cycles. Two patients (9%) developed a local-regional recurrence after 14 and 17 cycles of durvalumab. Extracranial distant metastases and brain metastases as first site of failure were detected in 4 (15%) and 2 (8%) patients, respectively. Three (13%) patients presented with symptomatic relapse. Our prospective study confirmed a favourable safety profile of durvalumab maintenance treatment after completion of CRT in unresectable stage, locally advanced NSCLC in a real-world setting. In a median follow-up time of 20.6 months, durvalumab was discontinued in 27% of all patients due to progressive disease. All patients with progressive disease were eligible for second-line treatment.