Real world assessment of clinical benefit with consolidation durvalumab following chemoradiotherapy in stage III unresectable non-small cell lung cancer.

Abstract

e18853 Background: The phase III PACIFIC trial compared the efficacy of consolidation durvalumab to placebo in newly diagnosed, unresectable stage III non-small cell lung cancer (NSCLC) who had not progressed after chemoradiotherapy (CRT). With a median follow-up of 34.2 months, the median progression free survival (PFS) was 16.9 months (13.0-23.9) compared to 5.6 months (4.6-7.7) for placebo (HR = 0.55, 95% CI,0.45-0.68). We report a real-world study that utilizes surrogate endpoints to assess duration of clinical benefit with consolidation durvalumab. Methods: OncoHealth, a digital health company, conducted a retrospective observational real-world study to assess time to treatment failure in patients with unresectable Stage III NSCLC who received consolidation durvalumab after completion of CRT between June 2018-June 2021. Data sources included electronic medical records (EMR) submitted with prior authorization (PA) requests to OncoHealth and medical claims data. With a data cut-off of 12/22/2022, real-world Time to Progression (rwTTP), and real-world Time to Next Treatment (rwTTNT) were evaluated to assess time to treatment failure. All end points were measured from durvalumab administration dates, rwTTP spanned until earliest date of clinician-assessed progression, and rwTTNT spanned until initiation of subsequent treatment. Results: Total of 281 patients with unresectable Stage III NSCLC who received durvalumab after completion of definitive CRT were identified. Median age was 71 years (range: 53 to 88), 57% male, 53% former smokers, 47% Stage IIIA, 52% non-squamous histology and 98% received concomitant platinum-based chemotherapy prior to durvalumab. Median time between completing CRT and initiating durvalumab was 41 days. With a cutoff date of 12/22/2022, and a median follow up of 28.4 months, 34% (n = 95) experienced disease progression. Sites of progression included lung, lymph nodes, adrenal, liver, bone and brain. The median rwTTP was 10.6 months (range: 2.0-38.1 months) and median rwTTNT was 12.4 months (range: 2.5-39.6 months). Conclusions: In this real-world study, the patient and disease characteristics available in EMR were comparable to those reported in the PACIFIC trial. The rwTTP and rwTTNT reported here suggest treatment failure occurred within one year of exposure to durvalumab and subsequent line of treatment was initiated shortly thereafter. Variables such as co-morbidities, performance status, treatment compliance, change of payers and barriers to treatment in real world will be further explored.