An orthogonal IL-2 and IL-2Rbeta
Menée in vitro et à l'aide de modèles murins de leucémie ou de lymphome, cette étude met en évidence l'intérêt thérapeutique d'un système utilisant des interleukines IL-2 modifiées et des lymphocytes CAR-T anti CD-19 exprimant un récepteur capable de lier ces interleukines modifiées
Chimeric antigen receptor (CAR) T cells induce durable responses in patients with refractory hematological tumors. However, low CAR T cell activity, poor engraftment, or short in-patient persistence can lead to tumor progression or relapse. Furthermore, excessive CAR T cell expansion and activation can result in life-threatening cytokine release syndrome (CRS). Thus, in-patient control of the CAR T cell population is essential. Interleukin-2 (IL-2) is a critical cytokine for T cell proliferation and effector function, but its clinical use is limited by immune-mediated toxicity. Here, we report on an orthogonal IL-2 receptor and ligand system that enables specific in vivo control of CAR T cell expansion and activation, wherein an orthogonal human IL-2 (STK-009) selectively pairs with an orthogonal human IL-2R
β (hoRb) expressed on CAR T cells. STK-009 expands hoRb-expressing CAR T cells in the presence and absence of tumor antigen and maintains the presence of stem cell memory T cells (TSCM) and effector T cells. In preclinical models of human CAR-refractory lymphoma, STK-009 treatment resulted in systemic and intratumoral expansion and activation of hoRb-expressing anti
–CD19-CD28
ζ CAR T cells (SYNCAR). The orthogonal IL-2 receptor/ligand system delivers complete responses in large subcutaneous lymphomas, even with substantially reduced CAR T cell doses, by selectively expanding and activating CAR T cells in vivo. STK-009 withdrawal allowed normal CAR T cell contraction, thereby limiting CRS induced by tumor antigen
–specific T cell activation. These data suggest that the orthogonal IL-2 receptor/ligand system provides the in vivo control necessary to maximize efficacy of CAR T therapies.