Patient-Reported Outcomes in OAK: A Phase III Study of Atezolizumab Versus Docetaxel in Advanced Non-Small-cell Lung Cancer

Background: The randomized phase III OAK (a study of atezolizumab compared with docetaxel in participants with locally advanced or metastatic non-small-cell lung cancer [NSCLC] who have failed platinum-containing therapy) trial investigated the anti-programmed cell death ligand 1 (PD-L1) antibody atezolizumab for advanced or metastatic, previously treated, NSCLC. Atezolizumab significantly improved overall survival (OS) compared with docetaxel (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.62-0.87; P = .0003; median OS, 13.8 vs. 9.6 months, respectively). Patient-reported outcomes (PROs) were collected to evaluate disease-related symptoms and health-related quality of life (HRQoL) to support the finding of a survival benefit.

Patients and methods: The first 850 patients were randomized to receive atezolizumab (1200 mg every 3 weeks) or docetaxel (75 mg/m² every 3 weeks). PROs were collected on day 1 of cycle 1, day 1 of every subsequent cycle, and at the end-of-treatment visit for patients who completed ≥ 1 baseline and 1 postbaseline PRO assessment. The European Organisation for the Research and Treatment of Cancer QoL questionnaire and lung cancer module were used to assess PROs.

Results: Atezolizumab delayed the time to deterioration (TTD) in physical function (HR, 0.75; 95% CI, 0.58-0.98) and role function (HR, 0.79; 95% CI, 0.62-1.00) and numerically improved patients' HRQoL from baseline compared with docetaxel. Atezolizumab also prolonged the TTD in chest pain (HR, 0.71; 95% CI, 0.49-1.05; P = .0823), although both arms showed an objective reduction relative to baseline. Overall, the patients had no clinically significant worsening in treatment-related symptoms, although the scores favored atezolizumab.

Conclusion: These PRO data support the clinical benefit of atezolizumab in patients with previously treated advanced or metastatic NSCLC. Atezolizumab prolonged the TTD of patients' limitations in role and physical functions compared with docetaxel.