Durvalumab consolidation therapy following chemoradiotherapy among patients with unresectable stage III non-small cell lung cancer (NSCLC) treated in a US community oncology network

295 Background: While the introduction of durvalumab consolidation therapy shifted the treatment paradigm for unresectable stage III NSCLC, few studies have examined real-world use of durvalumab in this patient population. Methods: This was a retrospective study of adult patients diagnosed with unresectable Stage III NSCLC between 8/1/2017-2/29/2020 who received chemoradiotherapy (CRT) followed by durvalumab consolidation therapy in The US Oncology Network. Structured electronic health record (EHR) data was used to screen for potentially eligible patients who received durvalumab consolidation. Through a targeted chart review, patients’ eligibility was verified. Study variables on patient demographics, clinical characteristics, CRT and durvalumab treatment patterns were sourced from structured and unstructured EHR data. Results: Among 1,626 patients who received CRT during the study observation period and were screened through structured records, 851 (52.3%) of these patients received durvalumab. Through chart review, 528 patients were verified to be eligible for this analysis (median age 70 years, 51.5% male, 18% Eastern Cooperative Oncology Group performance status [ECOG PS] score of 0, 59% with an ECOG PS score of 1). Across the study population, 73.9% received a total radiation dose between 54 and 66 Gy, with the rest receiving higher doses (6.5%), lower doses (3.2%) or doses not documented (15.8%). The mean and median time from end of radiation to post-CRT scan were 41 and 36 days, respectively; the mean and median time from end of radiation to durvalumab initiation were 58 and 47 days, respectively, with 57% of patients initiating durvalumab > 42 days. At the end of study observation period (median follow-up duration of 46.9 weeks), 173 of 528 patients (32.7%) were still actively receiving durvalumab treatment, 98 (18.6%) had completed planned treatment and 257 (48.7%) had discontinued treatment due to progression (18.2%), adverse events (17.2%), death (5.3%) or other reasons (8%). Conclusions: These results provide insights into real-world use of the PACIFIC regimen in a community setting with an older and more fragile population. Radiation therapy doses administered during CRT were largely consistent with the PACIFIC trial. There were delays in time to post-CRT scan and durvalumab initiation, with more than half of patients starting durvalumab > 42 days after CRT. These findings highlight opportunities for quality improvement measures in this population.