Single-cell dynamics of breakthrough toxicities after anakinra prophylaxis for axicabtagene ciloleucel in lymphoma

Chimeric antigen receptor (CAR) T-cell (CAR-T) therapy is limited by cytokine release syndrome (CRS) and neurotoxicity (NT). We sought to use once-daily prophylactic anakinra, an interleukin-1 (IL-1) receptor antagonist, to prevent CRS/NT that would require hospitalization (grade ≥2) in patients receiving axicabtagene ciloleucel for large-cell lymphoma, with the goal of facilitating outpatient therapy and management. Our study, in line with others, demonstrates that once-daily prophylactic anakinra is insufficient to prevent the development of toxicities that would require hospitalization in most patients. As part of the initial study design, we prospectively incorporated single-cell RNA sequencing to gain insight into the molecular immune signaling associated with breakthrough CRS and NT despite anakinra prophylaxis. In patients who developed breakthrough CRS or NT, we found that interferon gamma (IFN-γ) pathways and ligand-receptor activities were significantly enriched, as were cytokine levels of IFN-γ and CXCL10 in CD14+ monocytes. This correlated with increased IFN-γ and other cytokines in the peripheral blood. In infused CAR-T products, IL-4 and IL-10 anti-inflammatory pathways were negatively associated with grade ≥2 toxicities, regardless of anakinra treatment. These data identify IFN-γ as a potential key mechanism in CAR-T-associated toxicities, which is not inhibited by anakinra but may be otherwise targetable. This trial was registered at www.ClinicalTrials.gov as #NCT04150913.