Abstract 1386: NSCLC patient-derived organoids recapitulate tissue signalling and impairment of infiltrated immune cell activation predicting patients’ response to therapy.

Abstract Non-small cell lung cancer (NSCLC) with its rapid growth and early metastasis onset, represents the most common cause of cancer-related deaths worldwide. Current treatments offer limited long-term survival, necessitating novel approaches. Immunotherapy, specifically anti-PD1 and anti-PD-L1, has transformed NSCLC treatment, but only a small percentage of patients respond. There is an unmet need to predict immuno-therapy susceptibilities, achieve a cancer patient risk stratification and identify targeted therapies. Patient-derived organoids (PDOs) are in vitro 3D structures that recapitulate the complexity of the tumours from which they derived, showing a great potential as preclinical model for drug screening and tailored treatment. We used 12 PDO models established from chemotherapy-naïve high-risk NSCLC patients tissues collected at the Guy’s Hospital, London. Patients’ follow-up was performed for more than 24 months post resection/biopsy/surgery. PDOs were treated with cisplatin, then co-cultured with pre-activated immune cells in the presence of IO drugs and subjected to multiple assays including imaging, flow cytometry, genomic and transcriptomic analysis and proteomic from exosome isolation. This multi-omics approach allows for simultaneous analysis of different biological parameters before and after treatment to understand tumour cell interaction with immune cells and drug-induced changes. According to patients’ clinical response to standard of care treatment, PDOs were classified as responder (R) and not responder (NR). Cisplatin IC50, elaborated from PDOs cytotoxicity analysis, correlated with R and NR dichotomy, predicting the response status of the patients in vivo. When PDOs were cocultured with PBMC, counterintuitively, we observed a higher immune cells infiltration after cisplatin treatment in the NR-PDOs. Neither baseline CD45 infiltration nor the composition of infiltrating PBMC differed between NR and R-PDOs. However, in the baseline condition, the CD8pos cells infiltrating NR-PDOs presented a predominantly exhaustion profile. Transcriptomic analysis of untreated PDOs revealed higher activation of inflammatory response signalling in the NR-PDOs compared to responders, and the same signalling upregulation was identify from spatial transcriptomic analysis on primary tumour tissues derived from NR patients. Proteomic analysis of extracellular vesicles cargo also identified different protein content in R vs NR-PDO supporting the involvement of EV in the crosstalk between PDO and immune cells. We found that PDOs maintain the transcriptomic profile of the tissue they derived from with different activation of specific signalling that contributes to the creation of an inflammatory microenvironment and correlates with drug response status. Citation Format: Anna Pasto, Halh Al-Serori, Maria Fankhaenel, Zeinab Mokhtari, Debayan Mukherjee, Ruben Drews, Paul Barber, Jessica Davis, Lena Wedeken, Veronika Yankova, Jürgen Loskutov, James Monypenny, Nikunjkumar Prakashbhai Patel, Mint Htun, Michael Finn, Susan Ndagire, Eleni Karapanagiotou, Edmund Moon, Cheryl Gillett, Andrea Bille, Tony Ng. NSCLC patient-derived organoids recapitulate tissue signalling and impairment of infiltrated immune cell activation predicting patients’ response to therapy abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 1386.