e21058 Background: Definitive concurrent chemoradiation (cCRT) and durvalumab is a standard therapy for patients with unresectable stage III non-small cell lung cancers (NSCLC). Data is limited on outcomes with this regimen outside of clinical trials. Local-regional control rates to date remain undefined. Methods: We reviewed patients with stage III unresectable NSCLC treated between November 2017 and February 2019 with cCRT. Patients that received at least one cycle of durvalumab were further assessed for 12-month progression free survival (PFS), overall survival (OS), and the incidence and pattern of local-regional and metastatic failures. Disease-relapse was characterized to determine patients potentially eligible for metastasis-directed ablative therapies. Toxicities leading to durvalumab discontinuation were evaluated using CTCAE v.5.0. Results: Of the 83 patients with stage III NSCLC treated with cCRT (median 60Gy), 62 received durvalumab and were evaluable (median follow-up: 12 months). Patients (n = 21, 25%) did not receive durvalumab largely related to metastatic progression (n = 9) or persistent cCRT toxicity (n = 10). In the 62 durvalumab treated patients the median age was 66 (range: 49 - 86), 73% had stage IIIB (n = 33) or IIIC (n = 12) disease, and 58% (n = 36) had adenocarcinoma. The median time from cCRT end to durvalumab start was 1.5 months. Patients received a median of 8 months of durvalumab; 35% (n = 22) of patients completed 12 months of therapy. Common reasons for discontinuing durvalumab included disease progression (32%, 20/62) and toxicity (24%, 15/62). The estimated 12-month PFS and OS were 65% (95% CI: 51 - 79%) and 85% (95% CI: 75 - 95%), respectively. High TMB (≥ 8.8 mt/Mb) or PD-L1 (≥ 1% or PD-L1 ≥ 50%) did not predict improved PFS. Patients who discontinued durvalumab due to toxicity did not have inferior PFS. The cumulative 12-month incidence of local-regional and distant metastatic failures were 18% (95% CI: 5.9 - 30%) and 30% (95% CI: 16.3 - 44.5%), respectively. Of the 17 patients with distant metastases, 9 had oligometastases and would have been potential candidates for comprehensive ablative therapies. Conclusions: Outcomes and toxicities outcomes with cCRT and durvalumab in clinical practice align with the PACIFIC trial. Analysis of disease-relapse suggests a substantial minority of patients with disease progression may be potential candidates for metastasis-directed therapies. Local regional outcomes appear improved to historical data of cCRT alone.
One-Year Disease Outcomes in Stage III Non-Small Cell Lung Cancers Treated with Trimodality Therapy vs Concurrent Chemoradiation and Durvalumab