B cells and the coordination of immune checkpoint inhibitor response in patients with solid tumors.

Immunotherapy profoundly changed the landscape of cancer therapy by providing long-lasting responses in subsets of patients and is now the standard of care in several solid tumor types. However, immunotherapy activity beyond conventional immune checkpoint inhibition is plateauing, and biomarkers are overall lacking to guide treatment selection. Most studies have focused on T cell engagement and response, but there is a growing evidence that B cells may be key players in the establishment of an organized immune response, notably through tertiary lymphoid structures. Mechanisms of B cell response include antibody-dependent cellular cytotoxicity and phagocytosis, promotion of CD4+ and CD8+ T cell activation, maintenance of antitumor immune memory. In several solid tumor types, higher levels of B cells, specific B cell subpopulations, or the presence of tertiary lymphoid structures have been associated with improved outcomes on immune checkpoint inhibitors. The fate of B cell subpopulations may be widely influenced by the cytokine milieu, with versatile roles for B-specific cytokines B cell activating factor and B cell attracting chemokine-1/CXCL13, and a master regulatory role for IL-10. Roles of B cell-specific immune checkpoints such as TIM-1 are emerging and could represent potential therapeutic targets. Overall, the expanding field of B cells in solid tumors of holds promise for the improvement of current immunotherapy strategies and patient selection.

Safety and efficacy of nivolumab in elderly patients with metastatic clear cell renal cell carcinoma: Analysis of the NIVOREN GETUG-AFU 26 study.

INTRODUCTION: Immune checkpoint inhibitors are standard of care in metastatic renal cell carcinoma but their activity and safety in elderly patients is insufficiently explored. We evaluated outcomes of elderly patients with mRCC treated with nivolumab in the GETUG-AFU 26 NIVOREN phase 2 trial (NCT03013335) and conducted exploratory circulating biomarker analyses. METHODS: Patients with mRCC were treated with nivolumab after at least one antiangiogenic therapy. The main endpoint of this analysis was safety in patients ≥ 70 years old (y.o), as per the rate of treatment-related grade 3-5 events (TRAE). Secondary endpoints included overall response rate (ORR), progression-free survival (PFS), overall survival. Exploration of candidate biomarkers associated with aging included baseline circulating cytokines involved in inflammation, adhesion, immune checkpoints, angiogenesis (IL6, IL7, IL8, BAFF, CXCL13, VCAM-1, 4-1BB, VEGF). RESULTS: Of 720 patients, 515 were < 70 y.o and 205 ≥ 70 y.o. Patients ≥ 70 y.o exhibited numerically less IMDC poor risk disease (21.0% vs 26.9%), sarcomatoid component (4.9% vs 9.8%) or brain metastases (5.9% vs. 14.7%), but more previous treatment lines (≥ 2 in 54.1% vs 48.5%). TRAE were higher in patients ≥ 70 y.o (24.9% vs. 17.9%, p = 0.033). Respective ORR (19.2% vs. 22.1%) and median PFS (4.5 versus 3.0 months, HR 0.97 [95%CI 0.81-1.15]) were similar. Overall survival was shorter in patients ≥ 70 y.o (19.3 versus 26.9 months, HR 1.26 [95%CI 1.04-1.51]), but not significantly in a competitive risk model. Only V-CAM1 and 4-1BB were found to be increased in patients ≥ 70 y.o. CONCLUSIONS: Nivolumab displayed higher grade 3/4 TRAE but manageable toxicity in elderly patients, with sustained activity. Elderly patients did not display specific inflammatory or angiogenic circulating profiles.