Intensity-Modulated Radiotherapy for Locally Advanced Lung Cancer in the Immunotherapy Era: A Prospective Study WJOG12019L.

INTRODUCTION

Chemoradiotherapy (CRT) followed by durvalumab is the standard of care for unresectable locally advanced NSCLC. Limited prospective data have been reported on intensity-modulated radiotherapy (IMRT)-adapted CRT in the immunotherapy era.

METHODS

In this multicenter prospective observational study, patients underwent IMRT-adapted CRT (platinum-doublet chemotherapy plus 60 Gy IMRT in 30 fractions under a prespecified radiation protocol), followed by consolidative durvalumab. The primary outcome was the durvalumab introduction rate within 42 days post-CRT.

RESULTS

Thirty-two patients with unresectable locally advanced NSCLC were enrolled between November 2019 and February 2021. Among the 28 evaluable cases, durvalumab was introduced in 24 (85.7%, 90% confidence interval: 70.2%-95.0%) of 28 patients after CRT, achieving the primary end point. All 29 patients who received IMRT completed the scheduled 60 Gy radiotherapy dose. One year of durvalumab treatment was completed in 12 of 24 patients (50%). In the 24 patients who were durvalumab-introduced, the median progression-free survival and overall survival were 20.9 (95% confidence interval: 6.9-not evaluable) months and not reached, respectively. Two-year progression-free survival and overall survival rates were 44% and 73%, respectively. Among the 29 patients in the safety analysis set, there were no treatment-related deaths or grade 4 nonhematological adverse events. Pneumonitis grade 1 was observed in 13 patients (45%), grade 2 in seven (24%), and grade 3 in one (3%).

CONCLUSIONS

High durvalumab introduction rate was reported after the completion of IMRT-adapted CRT under a prespecified radiation protocol. Its efficacy has been suggested, with favorable safety profiles, including a low incidence of severe pneumonitis.

TRIAL REGISTRATION

University Hospital Medical Information Network database ID: UMIN000038366.