CAR-T cell-induced cytokine release syndrome is rapidly alleviated by tripterygium glycosides (preprint)

Background Cytokine release syndrome (CRS) is a life-threatening complication of chimeric antigen receptor T cell (CAR-T) therapy. Macrophages/ monocytes are mediators of CRS. Tripterygium glycosides is an immunomodulator which could inhibit macrophages/ monocytes in animal models.Methods Two patients with relapsed and refractory hematological malignancies developed CRS after receiving CAR-T therapy. They received short-term tripterygium glycosides orally.Results Both patients showed rapid mitigation of fever with evidently decrease in elevated inflammatory cytokines within 72 hours. The patients' monocytes diminished remarkably, while CAR-T cells were neglectably affected. Treatment of 30 ng/mL triptolide in ex vivo cultured patients' blood for 24 hours selectively deplete over half of monocytes. Single cell RNA sequencing suggested selective depletion of CD14+CD16+ monocytes with decreased pro-inflammatory cytokines.Conclusions The low-cost and orally available tripterygium glycosides could be a promising alternative for CAR-T induced CRS, as well as other diseases complicated with CRS, e.g., coronavirus disease 2019.

Tripterygium glycosides as a potential treatment for CAR-T induced cytokine release syndrome: implication of monocyte depletion (preprint)

Summary Background Cytokine release syndrome (CRS) is a potentially life-threatening complication of chimeric antigen receptor T (CAR-T) cell therapy. Recent studies indicated critical roles of macrophages and monocytes in CAR-T induced CRS. Here, we report rapid dissipation of CAR-T induced CRS in two patients after receiving Tripterygium glycosides (TG). Effects of triptolide, the major active component of TG, on macrophages and monocytes were examined in animal models. Methods Two patients with CRS after CAR-T cell therapy (for hematological malignancy) received TG (50 mg, p.o.). Flow cytometry analysis and single cell RNA sequencing (scRNAseq) were conducted to examine the effects of TG on immune cells. Potential effects of triptolide were also examined ex vivo using patient-derived monocytes, as well as in mice. Findings Rapid alleviation of fever and cytokine storm was observed within 72 hours after TG treatment. Blood concentration of triptolide ranged from 21 to 154 ng/mL during treatment. Flow cytometry and scRNAseq showed selective depletion of monocytes with minimal impact on CAR-T cells in both patients. In ex vivo experiments with patient-derived monocytes, triptolide dramatically inhibited the synthesis of pro-inflammatory cytokines (e.g., IL-6, IL-10, and IP-10). Triptolide also rapidly and selectively depleted peritoneal concanavalin A activated macrophages and monocytes in mice. Interpretation TG could be a promising treatment for CAR-T induced CRS, as well as other diseases with similar mechanisms, e.g., hemophagocytic lymphohistiocytosis and COVID-19. Our preliminary findings require further verification with properly designed clinical trials.