Assessing the predictive value of ctDNA on relapse in patients with resected stage IB-IIIA NSCLC treated with adjuvant chemotherapy plus concomitant atezolizumab followed by atezolizumab: BTCRC LUN 19-396.

TPS8592 Background: A standard of care treatment for most patients with stage II and III non-small cell lung cancer (NSCLC) and a PD-L1 > 1% is surgery followed by adjuvant (adj) histology-specific chemotherapy followed by 1 year of atezolizumab. The benefit of adding atezolizumab concomitantly to chemotherapy in the adj setting has not been reported. In addition, the optimal duration of adjuvant therapy is undefined. Emerging data have demonstrated the potential for ctDNA to predict clinical recurrence in patients with surgically resected lung, breast, and colon cancer. The current study explores the predictive value of ctDNA for early relapse in patients treated with adj chemotherapy plus atezolizumab. Methods: The LUN19-396 is a phase II biomarker study that enrolls pts with resected NSCLC stage IB (tumors ≥ 4cm), IIA, IIB, and select IIIA (T3N1-2, T4N0-2). The ctDNA will be assessed within 60 days post-surgery and then every 3 months up to 12 months. All pts will receive treatment with 4 cycles of Cisplatin 60-75mg/m2 + Docetaxel 60-75mg/m2 + Atezolizumab 1200mg IV on day 1 q 3w (for patients with squamous cell cancer) or Cisplatin 60-75mg/m2 + Pemetrexed 500mg/m2 + Atezolizumab 1200mg on day 1 IV q 3w (for patients with non-squamous cell), followed by up to 13 additional cycles of Atezolizumab 1200mg IV every 3w. This trial will enroll a total of 100 pts to achieve more than 80% power. The primary objective is to estimate the percentage of pts with detectable ctDNA after surgery who have clearance of ctDNA at designated time points during adjuvant therapy. The key secondary objective is to estimate the 1-year disease-free survival in pts with undetectable ctDNA after 4 cycles of adj chemotherapy plus atezolizumab who had detectable ctDNA after surgery. This trial has enrolled 17 pts as of February 8, 2022. Clinical trial information: NCT04367311.