Postoperative Chemotherapy Use and Outcomes From ADAURA: Osimertinib as Adjuvant Therapy for Resected EGFR-Mutated NSCLC.

Abstract

Adjuvant chemotherapy is recommended in patients with resected stage IIꟷIIIA (and select IB) NSCLC; however, recurrence rates are high. In the phase III, ADAURA study (NCT02511106), osimertinib demonstrated a highly statistically significant improvement in disease-free survival (DFS) in patients with resected stage IBꟷIIIA EGFRm NSCLC. Here, we report prespecified and exploratory analyses of adjuvant chemotherapy use and outcomes from ADAURA. Patients with resected stage IBꟷIIIA EGFRm NSCLC were randomized 1:1 to receive osimertinib or placebo for 3 years. Adjuvant chemotherapy before randomization was not mandatory, per physician and patient choice. DFS in the overall population (IBꟷIIIA), with/without adjuvant chemotherapy, was a prespecified analysis. Exploratory analyses included: adjuvant chemotherapy use by patient age, disease stage and geographical location; DFS by adjuvant chemotherapy use and disease stage. Overall, 410/682 patients (60%) received adjuvant chemotherapy (osimertinib, n = 203; placebo, n = 207) for a median duration of 4.0 cycles. Adjuvant chemotherapy use was more frequent in patients: aged <70 years (338/509; 66%) versus ≥70 years (72/173; 42%); with stage II-IIIA disease (352/466; 76%) versus stage IB (57/216; 26%); enrolled in Asia (268/414; 65%) versus outside of Asia (142/268; 53%). A DFS benefit favoring osimertinib versus placebo was observed in patients with (DFS HR = 0.16, 95% CI: 0.10ꟷ0.26) and without adjuvant chemotherapy (HR = 0.23, 95% CI: 0.13ꟷ0.40), regardless of disease stage. These findings support adjuvant osimertinib as an effective treatment for patients with stage IB-IIIA EGFRm NSCLC after resection, with or without prior adjuvant chemotherapy.