Ramalingam, Suresh S.

8534 Background: Immunotherapy (IO) has transformed treatment for non–small cell lung cancer (NSCLC), but not all patients (pts) benefit, underscoring the need for predictive biomarkers to guide IO versus chemotherapy (Ch). CheckMate 227 (CM227; NCT02477826) showed a survival benefit of first-line nivolumab plus ipilimumab (nivo+ipi) over Ch in stage IV NSCLC. CD8⁺ T cells are key mediators of antitumor immunity and are associated with IO benefit. We developed an artificial intelligence (AI)–based pipeline (VIGOR-CD8) that predicts spatial CD8⁺ immune signatures from routine baseline H&E whole-slide images using histopathology foundation model embeddings (H-Optimus-0) and virtual gene expression modeling (HE2Gene), and evaluated its ability to identify pts who do and do not derive IO benefit over Ch in CM227. Methods: 1,598 pts with advanced NSCLC were analyzed, including multi-institutional retrospective cohorts (n = 487; 65 for patch-level CD8⁺ prediction and overall survival (OS), 422 for patient-level OS) and a blinded CM227 validation subset (n = 1,111). For orthogonal validation, 86,470 H&E patches were co-registered with quantitative CD8⁺ immunofluorescence. H-Optimus-0 and HE2Gene immune-related embeddings were used to train a random forest classifier to predict patch-level CD8⁺ probability. Patch-level probabilities were aggregated into a patient-level CD8⁺ signature and dichotomized into biomarker-positive (B⁺) and biomarker-negative (B⁻) groups by the training-set median. Cox models assessed the impact of VIGOR-CD8 on OS. In CM227, prognostic and predictive utility were evaluated using treatment-specific analyses; investigators were blinded to outcomes, and models were trained on independent, non-overlapping cohorts. Results: VIGOR-CD8 was associated with longer OS in the testing cohort (n = 422; HR 0.68, 95% CI 0.53–0.87, p = 0.00163) and CM227 (n = 1,111; HR 0.8, 95% CI 0.67–0.96, p = 0.016), irrespective of treatment type and PD-L1 expression. Among pts with evaluable PD-L1, B⁺ pts treated with nivo+ipi had superior OS versus Ch (n = 617; HR 0.72, 95% CI 0.58–0.90, p = 0.003), while in B⁻ pts there was no significant OS difference between treatment arms (n = 130; HR 1.18, 95% CI 0.79–1.75, p = 0.436), supporting a predictive rather than purely prognostic role for VIGOR-CD8. Conclusions: An AI-derived CD8⁺ immune signature from routine baseline H&E slides was associated with favorable OS in CM227 and predicted differential benefit from nivo+ipi versus Ch. VIGOR-CD8 may help identify advanced NSCLC pts most likely to benefit from first-line dual IO, but further validation in independent and prospective trials is warranted.

8000 Background: The NCI’s ALCHEMIST program has screened thousands of patients with resected lung adenocarcinoma for mutations in EGFR and ALK. EA5142 studied the efficacy of adjuvant nivolumab after standard of care adjuvant therapy in patients with resected lung adenocarcinoma without sensitizing EGFR and ALK alterations and squamous cell carcinoma. Methods: Patients enrolled in the ALCHEMIST screening trial (A151216) with resected NSCLC tumors at least 4 cm and/or lymph node positive (N1/2) (for lung adenocarcinoma, without sensitizing EGFR and ALK alterations), were centrally tested for tumor cell PD-L1 expression using the DAKO 28-8 clone. After completion of all planned adjuvant therapy (chemotherapy and/or post-operative radiation) patients were randomized 1:1 to adjuvant nivolumab 480 mg IV every 4 weeks for up to 1 year or best supportive care. Patients were stratified by tumor histology, stage (AJCC 7 th edition IB/IIA vs IIB/IIIA), prior adjuvant treatment, and PD-L1 status (<1% vs ≥1%). The primary study endpoints were disease free survival (DFS) in all patients and in patients with high tumor PD-L1 expression (≥50%). Overall survival was powered to be tested hierarchically, if DFS was positive. Results: Between July 2016 and October 2019, 935 patients were randomized across 378 sites. The treatment arms were balanced for age (median 66 years), sex (52% male), smoking status (10% never smoked), histology (29% squamous), stage and PD-L1 expression (29% PD-L1 high). With a median follow-up of 72.6 months, nivolumab did not improve DFS in the intention to treat population (median DFS 71.3 months vs. 68.8 months in observation arm), hazard ratio (HR) 0.97 (95% CI 0.81-1.17, p=0.78) or the PD-L1 ≥50% subset (median DFS 89.8 months vs. 78.5 months in observation arm), HR 0.86 (95% CI 0.59-1.25, p=0.43). In multivariate analysis, adjusting for age, gender, and smoking history, the DFS HR was 0.99 (95% CI 0.82-1.19, p=0.89) in all randomized patients and 0.82 (95% CI 0.56-1.2, p=0.31) in the PD-L1 ≥50% subset. As the primary recurrence endpoint included any lung cancer, including new primaries, a sensitivity analysis was performed excluding new primary lung cancers, DFS HR 0.97 (95% CI 0.80-1.18, p=0.76) in all patients and HR 0.88 (95% CI 0.60-1.30, p=0.52 in the ≥50% subset. The median duration of treatment with adjuvant nivolumab was 9.4 months (range 0-12.7 months). The most common reasons for nivolumab discontinuation were adverse event (29%), patient withdrawal (11%), and disease progression while on treatment (10%). Treatment related grade 3-5 toxicities were reported in 25% of patients: Grade 3: 23%, Grade 4: 2%, Grade 5: <1%. Conclusions: In patients with resected NSCLC (≥4cm or LN+, EGFR/ALK -) adjuvant nivolumab did not improve DFS, irrespective of tumor PD-L1 expression. Clinical trial information: NCT02595944 .