Project description:Phosphoinositide 3-kinase δ (PI3Kδ) plays key roles in lymphocytes and inhibitors targeting this PI3K have been approved for hematological malignancies. While preclinical data in hematological and solid tumor models have demonstrated that PI3Kδ inhibitors (PI3Kδi) can induce anti-tumor immunity, the impact of PI3Kδi in human solid tumors remains unknown. Here, we assessed the effects of the PI3Kδi AMG319 in patients with early stage head and neck cancer in a neoadjuvant, double-blind and placebo-controlled randomised phase-II trial. We find that PI3Kδ inhibition decreases tumor-infiltrating TREG cells and causes heightened cytotoxic potential of tumor-infiltrating CD8+ and CD4+ T cells. Loss of intratumoral TREG cells and an increase in the frequency of activated TREG cells in the blood post-treatment are indicative of systemic effects on TREG cell tissue retention and maintenance. At the chosen AMG319 dosing, the occurrence of immune-related adverse events caused treatment discontinuation in 43% of drug-treated patients, further suggestive of systemic effects on TREG cells. Consistent with this notion, in a murine syngeneic tumor model, PI3Kδi caused a decrease in TREG cells in both tumor and non-malignant tissues and affected TREG subtype composition, maintenance and functionality.
Project description:Phosphoinositide 3-kinase δ (PI3Kδ) plays key roles in lymphocytes and inhibitors targeting this PI3K have been approved for hematological malignancies. While preclinical data in hematological and solid tumor models have demonstrated that PI3Kδ inhibitors (PI3Kδi) can induce anti-tumor immunity, the impact of PI3Kδi in human solid tumors remains unknown. Here, we assessed the effects of the PI3Kδi AMG319 in patients with early stage head and neck cancer in a neoadjuvant, double-blind and placebo-controlled randomised phase-II trial. We find that PI3Kδ inhibition decreases tumor-infiltrating TREG cells and causes heightened cytotoxic potential of tumor-infiltrating CD8+ and CD4+ T cells. Loss of intratumoral TREG cells and an increase in the frequency of activated TREG cells in the blood post-treatment are indicative of systemic effects on TREG cell tissue retention and maintenance. At the chosen AMG319 dosing, the occurrence of immune-related adverse events caused treatment discontinuation in 43% of drug-treated patients, further suggestive of systemic effects on TREG cells. Consistent with this notion, in a murine syngeneic tumor model, PI3Kδi caused a decrease in TREG cells in both tumor and non-malignant tissues and affected TREG subtype composition, maintenance and functionality.
Project description:Chimeric antigen receptor (CAR)-T cell therapies have shown great success in treating hematologic malignancies. Nonetheless, their therapeutic effect on solid tumors remains to be improved. Recently, macrophages have attracted great attention, given their ability to infiltrate solid tumors, phagocytize tumor cells as well as their immunomodulatory capacities. The first generation of CD3ζ-based CAR-macrophages demonstrated that the CAR could stimulate macrophage phagocytosis in a tumor antigen-dependent way. Here, we genetically engineered induced pluripotent stem cell (iPSC)-derived macrophages (iMACs) with TLR4 intracellular TIR domain-containing CARs against EGFRvIII and GPC3, which yielded markedly enhanced antitumor effect in two different solid tumor models including glioblastoma, and hepatocellular carcinoma in which complete remission was achieved with CAR-iMACs alone or in combination with CD47 antibody. Moreover, the tandem CD3ζ-TIR-CAR, or the “second-generation” design of TIR-based dual signaling CAR, endowed iMACs with both target engulfment/efferocytosis capacity against antigen-expressing solid tumor cells, and potency of antigen-dependent M1 state polarization and M2 state resistance in an NF-κB dependent manner. We also illustrated a surprising mechanism of tumor cell elimination by CAR-induced efferocytosis against tumor cell apoptotic bodies. Taken together, we established the next generation CAR-iMACs equipped with orthogonal phagocytosis and polarization capacity for better antitumor functions in treating solid tumors.
Project description:Mutations or aberrant upregulation of the histone methyltransferase EZH2 occur frequently in human cancers yet EZH2-targeted therapies have only shown very limited clinical benefits in hematological malignancies. We report here that upon EZH2 inhibition, MLL1 interacts with p300/CBP complex that directs H3K27me loss to gain of H3K27ac modification. This histone modification crosstalk leads to transcriptional reprogramming that restricts the therapeutic response to EZH2 inhibition. Concurrent inhibition of H3K27 methylation and acetylation results in transcriptional repression and growth dependency on the MAPK signaling pathway in a large cancer subset. In pre-clinical models encompassing a broad spectrum of EZH2-aberrant solid tumors, a combination of EZH2 and BRD4 inhibitors or a triple-combination including MAPK inhibition display robust efficacy with tolerable toxicity, in particular in liver and pancreatic cancers. Our results suggest an attractive precision treatment and patient stratification strategy for EZH2-aberrant tumors on the basis of intrinsic MLL1 expression and feedback MAPK activation.
Project description:A phase I/II study of PI3Kinase inhibition (copanlisib) and anti-PD-1 antibody nivolumab in relapsed/refractory solid tumors with expansions in mismatch-repair proficient (MSS) colorectal cancer.