Neoadjuvant Atezolizumab and Chemotherapy for Non-Squamous Non-Small Cell Lung Cancer: Efficacy and Safety Results of an Open-Label, Single-Arm, Phase II Trial.

Immune checkpoint inhibitors have shown promising results in the neoadjuvant treatment of resectable non-small cell lung cancer. This open-label, single-arm, prospective, monocentric trial evaluated the efficacy and safety of neoadjuvant atezolizumab plus carboplatin/nab-paclitaxel in patients with resectable non-squamous non-small cell lung cancer. Patients with previously untreated, pathologically confirmed, non-squamous non-small cell lung cancer in stage II, IIIA, and select IIIB (T3N2 only) were treated with atezolizumab and carboplatin/nab-paclitaxel for 3 cycles followed by curative intent surgery. Major pathologic response (MPR) was defined as primary endpoint. 20 patients with histologically confirmed pulmonary adenocarcinoma in TNM-stage IIA (n = 1, 5%), stage IIB (n = 7, 35%), and stage IIIA (n = 12, 60%) were enrolled and treated according to the study protocol. 151 treatment-related adverse events were recorded, and 13 patients (65%) had treatment-related adverse events of grade 3 or higher. There were no grade 5 events. All patients underwent complete anatomical resection (R0). MPR was observed in 9 patients (45%), including 5 (25%) patients with complete pathological response. The proportion of remaining viable tumor showed a significant but weak association to the relative tumor size change in CT (p = 0.018) and the relative change in SUVmax (p = 0.006). In conclusion, neoadjuvant chemoimmunotherapy with atezolizumab achieved a promising MPR-rate of 45% while being well tolerated and allowing a safe and complete surgical resection. These results strongly support the further investigation of atezolizumab as preoperative therapy in resectable non-small cell lung cancer and underline the continued need to develop biomarkers of response.