LAUSR

2531 Background: Immune checkpoint inhibitors plus chemotherapy had showed benefits for advanced non–small-cell lung cancer (NSCLC) patients without targetable mutations. Autologous cytokine-induced killer (CIK) cells can restore the antitumor immunity to improve patient outcome. Combining CIK cells with anti-PD-1 mAb plus chemotherapy may strengthen the results in patients with advanced NSCLC. Methods: This is a single-center, open-label, phase 1b trial of combination CIK cells with sintilimab (anti-PD-1 mAb) plus chemotherapy in stage IIIB-IV NSCLC patients. Systemic therapy naïve patients received platinum-based doublet chemotherapy, sintilimab, and CIK cells every 3 weeks for 4 cycles，then sintilimab, and CIK cells for maintenance therapy until disease progression or unacceptable toxicity. Results: From May 2019 to Jan 2021, 34 patients (19 squamous， 15 non-squamous NCSLC)aged 46-73 years (median age 64 years) were enrolled. Among 32 evaluable patients, the ORR was 81.3% (73.7% in squamous and 92.3% in non-squamous NSCLC)and DCR was 100%. Among the 25 PR assessed by RECIST, CMR was demonstrated in 5 (23.1%) by PET-CT. Among 3 patients with brain metastases, 2 patients achieve intracranial CR, and 1 was PR. With a median follow-up of 7.5 months, the median DOR was not reached (range 0.5m-NA), and the median PFS and OS were not mature. Grade 3 or more TRAEs included pneumonia (n = 3); thrombocytopenia, leukopenia (n = 2 each); anemia, dysphagia, cardiomyopathy, rash (n = 1 each). Biomarkers and subgroups which correlated with efficacy and AEs are being analyzed included TMB, PDL1 expression, distribution of TILs, cytokines and so on. Conclusions: CIK cells therapy in combination with sintilimab plus chemotherapy were well tolerated and showed encouraging efficacy. Further studies are warranted to confirm these preliminary results. Research Sponsor: Tianjin Medical University Cancer Institute and Hospital. Clinical trial information: NCT03987867. [Table: see text]