Sandrine Faivre

Background: Buparlisib, combined with paclitaxel, improved survival in BERIL-1 trial patients with recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC). However, predictive biomarkers of benefit remain undefined. Objective: To evaluate whether spatial biomarkers extracted from hematoxylin and eosin (H&E) slides using artificial intelligence (AI) can predict overall survival benefit from buparlisib. Methods: Whole-slide H&E images from BERIL-1 trial patients were analyzed using a deep learning model trained to segment tissue compartments and classify cell phenotypes. Three predefined spatial features were evaluated: tumor-infiltrating lymphocyte density, tumor microenvironment heterogeneity, and granulocyte fraction in the tumor invasive margin. Cox proportional hazards model assessed biomarker-treatment interactions. Results: Of 158 trial participants, 144 had available slides. High tumor-infiltrating lymphocyte density (>10%) was associated with significantly improved overall survival with buparlisib versus placebo (HR, 0.25 (95% CI, 0.01–0.64; p = 0.002)), as were high tumor microenvironment heterogeneity (HR, 0.47 (95% CI, 0.27–0.80; p = 0.005)) and granulocyte enrichment in the tumor invasive margin (HR, 0.51 (95% CI, 0.30–0.88; p = 0.01)); within-arm proximity analysis showed higher granulocyte–tumor-cell proximity correlated with improved overall survival on buparlisib (HR, 0.32 (95% CI, 0.18–0.58; p < 0.001)). AI-derived spatial metrics outperformed CD3 immunohistochemistry. Among oropharyngeal tumors, HPV-positive cases were more frequent in patients with high tumor-infiltrating lymphocytes. Conclusions: AI-extracted spatial features from H&E slides were associated with overall survival benefit from buparlisib in R/M HNSCC. These scalable biomarkers support image-based patient selection strategies and are being prospectively evaluated in the BURAN phase 3 trial.

Tumor-associated macrophages (TAMs) and other PD-L1-expressing immune cells play a key role in head and neck squamous cell carcinoma (HNSCC). As PD-1 inhibitors have become standard therapy for recurrent/metastatic disease and are now used perioperatively in locally advanced resectable cases, understanding their impact on TAMs dynamics is critical. This study investigated the association between clinical features and TAMs prevalence in HNSCC, and their potential role in tumor progression and resistance to PD-1 blockade. Tumor samples from HNSCC patients were analyzed by simplex and multiplex immunohistochemistry, and fresh tumor slices were cultured ex vivo with PD-1 inhibitors. CD68 + and CD163 + macrophages and PD-L1 expression were quantified and correlated with clinical parameters. In a tissue microarray cohort of 96 patients, CD68 + and CD163 + macrophages were more abundant in oral and oropharyngeal tumors compared to laryngeal and hypopharyngeal carcinomas ( p = 0.001 and p = 0.06, respectively). In 10% of cases, TAMs formed a barrier between tumor nests and immune infiltrates. Among nine patients with matched pre- and post-immunotherapy samples, TAMs density significantly increased post-treatment ( p = 0.01 and p = 0.03), with CD163 + macrophages clustering at the tumor periphery in 78% of cases. Multiplex staining confirmed this spatial reorganization. Ex vivo exposure to PD-1 inhibitors reproduced the increase in TAMs. These results suggest that PD-1 blockade may foster M2-like macrophage accumulation, potentially contributing to immune evasion. This underscores the need for prospective studies and the development of macrophage-targeted strategies, particularly in the emerging context of perioperative immunotherapy in HNSCC.

PURPOSE: MET amplification ( METamp) has been reported in 1%-5% of patients with hepatocellular carcinoma (HCC) and may be sensitive to MET inhibition. Tepotinib, a selective MET inhibitor, has shown promising activity in HCC with MET overexpression. We investigated the preclinical and clinical activity of tepotinib in HCC with METamp ( MET gene copy number [GCN] ≥5), including high-level METamp ( MET GCN ≥10). METHODS: Preclinical antitumor activity of tepotinib 100 mg/kg (orally, days 1-5, every 7 days, 3-5 weeks; 3-12 replicates) was evaluated according to METamp status, as determined using the nCounter platform (NanoString), in 37 HCC patient-derived xenografts (PDXs) in immunodeficient mice. Clinical outcomes were evaluated in patients with METamp by fluorescence in situ hybridization who received tepotinib 500 mg (450 mg active moiety) in two phase Ib/II trials in HCC with MET overexpression. RESULTS: Across the PDX models, tepotinib induced complete or near-complete tumor regression in the only two models with high-level METamp. Median tumor volume reductions were 100% and 99.8% in models with MET GCN 47.1 and 44.0, respectively. Across the two clinical trials, 15/121 patients had METamp. Disease control was achieved by 11/15 patients with METamp (complete response [CR], n = 1; partial response [PR], n = 4; stable disease [SD], n = 6) and 4/4 with high-level METamp (CR, n = 1; PR, n = 2; SD, n = 1). All three patients with high-level METamp and objective response received treatment for >1 year, including one patient who received first-line tepotinib for >6 years. CONCLUSION: High-level METamp may be an oncogenic driver in HCC that is sensitive to MET inhibitors such as tepotinib.

Outcomes for patients with advanced hepatocellular carcinoma (HCC) remain poor despite recent progress in drug development. Emerging data implicate FGF19 as a potential HCC driver, suggesting its receptor, FGFR4, as a novel therapeutic target. We evaluated fisogatinib (BLU-554), a highly potent and selective oral FGFR4 inhibitor, in a phase I dose-escalation/dose-expansion study in advanced HCC using FGF19 expression measured by IHC as a biomarker for pathway activation. For dose escalation, 25 patients received 140 to 900 mg fisogatinib once daily; the maximum tolerated dose (600 mg once daily) was expanded in 81 patients. Fisogatinib was well tolerated; most adverse events were manageable, grade 1/2 gastrointestinal events, primarily diarrhea, nausea, and vomiting. Across doses, the overall response rate was 17% in FGF19-positive patients [median duration of response: 5.3 months (95% CI, 3.7–not reached)] and 0% in FGF19-negative patients. These results validate FGFR4 as a targetable driver in FGF19-positive advanced HCC.Significance:Fisogatinib elicited clinical responses in patients with tumor FGF19 overexpression in advanced HCC. These results validate the oncogenic driver role of the FGFR4 pathway in HCC and the use of FGF19 as a biomarker for patient selection.See related commentary by Subbiah and Pal, p. 1646.This article is highlighted in the In This Issue feature, p. 1631

Acquired resistance to protein kinase C (PKC) modulators may explain the failure of clinical trials in patients with cancer. Herein, we established a human colon cancer cell line resistant to PEP005, a drug that inhibits PKCα and activates PKCδ. Colo205-R cells, selected by stepwise exposure to PEP005, were >300-fold more resistant to PEP005 than parental Colo205-S cells and were cross-resistant to phorbol 12-myristate 13-acetate, bryostatin, bistratene A, and staurosporine. No PKCα or PKCδ mutation was detected in Colo205-S and Colo205-R cells. Changes in Colo205-R cells were reminiscent of the epithelial-to-mesenchymal transition (EMT) phenotype. Accordingly, Colo205-R cells were more invasive than Colo205-S in Matrigel assays and in mouse xenografts. We also found an increased mRNA expression of several EMT genes, such as those encoding for transforming growth factor-β and vimentin, along with a decreased mRNA expression of genes involved in epithelial differentiation, such as CDH1 (E-cadherin), CLDN4 (claudin 4), S100A4, and MUC1, in Colo205-R compared with Colo205-S cells in vitro and in vivo. Interestingly, high expression of ET-1 was shown in Colo205-R cells and correlated with low sensitivity to PEP005 and staurosporine in a panel of 10 human cancer cell lines. Inhibition of the ET-1 receptor ETR-A with bosentan restored the antiproliferative effects of PEP005 in Colo205-R cells and decreased the invasive properties of this cell line. Exogenous exposure to ET-1 and silencing ET-1 expression using small interfering RNA modulated cell signaling in Colo205-S and Colo205-R. In summary, acquired resistance to PEP005 was associated with expression of EMT markers and activates the ET-1/ETR-A cell signaling. [Cancer Res 2009;69(10):4260–69]

Mammalian target of rapamycin (mTOR) regulates cellular functions by integrating intracellular signals and signals from the tumor microenvironment (TME). The PI3K-AKT-mTOR pathway is activated in 70% of head and neck squamous cell carcinoma (HNSCC) and associated with poor prognosis. This phase I-II study investigated the effect of mTOR inhibition using weekly everolimus (30 mg for dose level 1, 50 mg for dose level 2) combined with weekly induction chemotherapy (AUC2 carboplatin and 60 mg/m² paclitaxel) in treatment-naïve patients with locally advanced T3-4/N0-3 HNSCC. Patients received 9 weekly cycles before chemoradiotherapy. Objectives were safety and antitumor activity along with tissue and blood molecular biomarkers. A total of 50 patients were enrolled. Among 41 evaluable patients treated at the recommended dose of 50 mg everolimus weekly, tolerance was good and overall response rate was 75.6%, including 20 major responses (≥50% reduction in tumor size). A significant decrease in expression of p-S6K (p-value: 0.007) and Ki67 (p-value: 0.01) was observed in post-treatment tumor tissue. Pro-immunogenic cytokine release (Th1 cytokines IFN-γ, IL-2, and TNF-β) was observed in the peripheral blood. The combination of everolimus and chemotherapy in HNSCC was safe and achieved major tumor responses. This strategy favorably impacts the TME and might be combined with immunotherapeutic agents.