Clinical Factors Associated With Non-Completion of Durvalumab Maintenance Therapy After Chemoradiotherapy in Patients...

Durvalumab maintenance following concurrent chemoradiotherapy (CCRT) is the standard treatment for unresectable stage III non-small cell lung cancer (NSCLC); however, some patients discontinue treatment before completing 12 months. We explored whether pretreatment peripheral blood inflammatory and nutritional markers are associated with durvalumab non-completion.

We retrospectively reviewed patients with locally advanced NSCLC who initiated durvalumab between August 2018 and April 2024. Laboratory data obtained within 7 days before the first dose were analyzed. Completion was defined as 12 months (365 days) of treatment. Routine laboratory parameters and inflammatory/nutritional indices were compared between completers and non-completers. Exploratory multivariable logistic regression and clinically adjusted sensitivity analyses were performed.

Eighty patients were included: 36 completers and 44 non-completers. Durvalumab was discontinued because of disease progression (n = 24), radiation pneumonitis (n = 14), immune-related adverse events (n = 5), and aspiration pneumonia (n = 1). Conventional inflammatory indices did not differ between groups. In the primary exploratory multivariable model, a higher albumin-to-globulin (A/G) ratio was associated with durvalumab completion (OR, 9.74; 95% CI, 1.01-93.9; p = 0.048), whereas RDW-SD showed a non-significant inverse association with completion (OR, 0.942; 95% CI, 0.883-1.01; p = 0.076). After adjustment for age, ECOG performance status, and histology, these associations were not statistically significant.

Lower A/G ratio and higher RDW-SD before durvalumab initiation may be associated with non-completion. Given the exploratory design, limited sample size, attenuation after clinical adjustment, and heterogeneous reasons for discontinuation, these findings require external validation.