Abstract

Julian Taugner¹, Lukas Käsmann¹, Chukwuka Eze¹, Benedikt Flörsch¹, Julian Guggenberger¹, Amanda Tufman², Niels Reinmuth³, Thomas Duell³, Claus Belka¹, Farkhad Manapov¹

¹LMU Munich, radiation oncology, Munich, Germany; ²LMU Munich, pneumology, Munich, Germany; ³Asklepios Fachkliniken München Gauting, thoracic oncology, Munich, Germany

Prospective evaluate of the clinical use and real-world efficacy of durvalumab maintenance treatment after chemoradiotherapy (CRT) in inoperable non-small cell lung cancer (NSCLC).

All consecutive patients with PD-L1 expressing NSCLC treated in a single tertiary cancer centre after October 2018 were included. Every three months after CRT, physical examinations, PET/CT and/or contrast-enhanced CT-Thorax/Abdomen were performed. Descriptive treatment pattern analyses, including reasons of discontinuation and salvage treatment, were undertaken. All statistics were calculated from the last day of thoracic irradiation (TRT).

Twenty-eight patients with PD-L1 expressing unresectable NSCLC were included. Median follow up achieved 19.8 months (range: 1.2-30.6). Durvalumab was initiated after a median of 23 (range: 13-103) days after completion of CRT. In median 14 (range: 2-24) cycles of durvalumab were applied within 5.8 (range 1-12.7) months. Seven patients (25%) are still in treatment and eight (29%) have completed treatment with 24 cycles. Maintenance treatment was discontinued in 13 (46%) patients: In 7 (25%) patients treatment was discontinued due to progression, 4 (14%) 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 (14%) 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 83% and 57%, median PFS was not reached. No case of hyperprogression was documented. Eight (29%) 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 (7%) 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 (14%) and 2 (7%) patients, respectively. Three (11%) patients presented with symptomatic relapse. 

Durvalumab maintenance after completion of CRT in PD-L1 expressing inoperable NSCLC patients has a favourable safety profile. After a median follow-up of 19.8 months, durvalumab was discontinued in 25% of all patients due to progressive disease. All patients with progressive disease were eligible for second-line treatment.